Pure history

8 files changed, 680 insertions, 268 deletions

diff --git a/Cargo.lock b/Cargo.lock
index a504a3f..6e73af8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3,6 +3,15 @@
 version = 4
 
 [[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
+[[package]]
 name = "arrayref"
 version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -15,18 +24,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
 
 [[package]]
+name = "autocfg"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
+
+[[package]]
 name = "base64"
 version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
 
 [[package]]
-name = "bitflags"
-version = "2.13.0"
+name = "bincode"
+version = "1.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4388bee8683e3d04af747c73422af53102d2bd24d9eadb6cbc100baef4b43f8"
+checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
 dependencies = [
- "serde_core",
+ "serde",
 ]
 
 [[package]]
@@ -41,6 +56,22 @@ dependencies = [
 ]
 
 [[package]]
+name = "bumpalo"
+version = "3.20.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72f5acc6cb2ba439de613abc23857ec3d78374d8ed5ac84e9d11336e87da8649"
+
+[[package]]
+name = "cc"
+version = "1.2.67"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e17dd265a7d0f31ef544e1b20e03add05d3b45b491b633b10d67145d2acc1a38"
+dependencies = [
+ "find-msvc-tools",
+ "shlex",
+]
+
+[[package]]
 name = "cfg-if"
 version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -58,19 +89,29 @@ dependencies = [
 ]
 
 [[package]]
+name = "chrono"
+version = "0.4.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1aa79e62e7697b8e29b513a68abacf485adcd1fe8284a4316c5ae868e6633327"
+dependencies = [
+ "iana-time-zone",
+ "js-sys",
+ "num-traits",
+ "wasm-bindgen",
+ "windows-link",
+]
+
+[[package]]
 name = "constant_time_eq"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
 [[package]]
-name = "convert_case"
-version = "0.10.0"
+name = "core-foundation-sys"
+version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "633458d4ef8c78b72454de2d54fd6ab2e60f9e02be22f3c6104cdc8a4e0fceb9"
-dependencies = [
- "unicode-segmentation",
-]
+checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
 [[package]]
 name = "cpufeatures"
@@ -88,29 +129,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61803da095bee82a81bb1a452ecc25d3b2f1416d1897eb86430c6159ef717c17"
 
 [[package]]
-name = "derive_more"
-version = "2.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d751e9e49156b02b44f9c1815bcb94b984cdcc4396ecc32521c739452808b134"
-dependencies = [
- "derive_more-impl",
-]
-
-[[package]]
-name = "derive_more-impl"
-version = "2.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "799a97264921d8623a957f6c3b9011f3b5492f557bbb7a5a19b7fa6d06ba8dcb"
-dependencies = [
- "convert_case",
- "proc-macro2",
- "quote",
- "rustc_version",
- "syn",
- "unicode-xid",
-]
-
-[[package]]
 name = "directories"
 version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -154,6 +172,36 @@ dependencies = [
 ]
 
 [[package]]
+name = "find-msvc-tools"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
+
+[[package]]
+name = "futures-core"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e3450815272ef58cec6d564423f6e755e25379b217b0bc688e295ba24df6b1d"
+
+[[package]]
+name = "futures-task"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "037711b3d59c33004d3856fbdc83b99d4ff37a24768fa1be9ce3538a1cde4393"
+
+[[package]]
+name = "futures-util"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "389ca41296e6190b48053de0321d02a77f32f8a5d2461dd38762c0593805c6d6"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "pin-project-lite",
+ "slab",
+]
+
+[[package]]
 name = "getrandom"
 version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -188,6 +236,47 @@ dependencies = [
 ]
 
 [[package]]
+name = "iana-time-zone"
+version = "0.1.65"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e31bc9ad994ba00e440a8aa5c9ef0ec67d5cb5e5cb0cc7f8b744a35b389cc470"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "log",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "itoa"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+
+[[package]]
+name = "js-sys"
+version = "0.3.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53b44bfcdb3f8d5837a46dae1ca9660a837176eee74a28b229bc626816589102"
+dependencies = [
+ "cfg-if",
+ "futures-util",
+ "wasm-bindgen",
+]
+
+[[package]]
 name = "lazy_static"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -209,19 +298,41 @@ dependencies = [
 ]
 
 [[package]]
+name = "log"
+version = "0.4.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ceec5bc11778974d1bcb055b18002eba7f4b3518b6a0081b3af5f21666da9ad"
+
+[[package]]
+name = "memchr"
+version = "2.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf8baf1c55e62ffcace7a9f06f4bd9cd3f0c4beb022d3b367256b91b87513d98"
+
+[[package]]
 name = "mood"
 version = "0.1.0"
 dependencies = [
- "derive_more",
+ "bincode",
+ "chrono",
  "directories",
  "expanduser",
  "rand",
- "ron",
  "serde",
+ "serde_json",
  "walkdir",
 ]
 
 [[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
 name = "once_cell"
 version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -234,6 +345,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
 
 [[package]]
+name = "pin-project-lite"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
+
+[[package]]
 name = "proc-macro2"
 version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -313,20 +430,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "ron"
-version = "0.12.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81116b9531d61eabc41aeb228e4b6b2435bcca3233b98cf3b3077d4e6e9debb3"
-dependencies = [
- "bitflags",
- "once_cell",
- "serde",
- "serde_derive",
- "typeid",
- "unicode-ident",
-]
-
-[[package]]
 name = "rust-argon2"
 version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -339,13 +442,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "rustc_version"
-version = "0.4.1"
+name = "rustversion"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
-dependencies = [
- "semver",
-]
+checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
 [[package]]
 name = "same-file"
@@ -357,12 +457,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "semver"
-version = "1.0.28"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
-
-[[package]]
 name = "serde"
 version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -393,6 +487,31 @@ dependencies = [
 ]
 
 [[package]]
+name = "serde_json"
+version = "1.0.150"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
+dependencies = [
+ "itoa",
+ "memchr",
+ "serde",
+ "serde_core",
+ "zmij",
+]
+
+[[package]]
+name = "shlex"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
+
+[[package]]
+name = "slab"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c790de23124f9ab44544d7ac05d60440adc586479ce501c1d6d7da3cd8c9cf5"
+
+[[package]]
 name = "syn"
 version = "2.0.118"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -444,30 +563,12 @@ dependencies = [
 ]
 
 [[package]]
-name = "typeid"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc7d623258602320d5c55d1bc22793b57daff0ec7efc270ea7d55ce1d5f5471c"
-
-[[package]]
 name = "unicode-ident"
 version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
 [[package]]
-name = "unicode-segmentation"
-version = "1.13.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
-
-[[package]]
-name = "unicode-xid"
-version = "0.2.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
-
-[[package]]
 name = "walkdir"
 version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -490,6 +591,51 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
+name = "wasm-bindgen"
+version = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b067c0c11094aef6b7a801c1e34a26affafdf3d051dba08456b868789aaf9a4"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "rustversion",
+ "wasm-bindgen-macro",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "167ce5e579f6bcf889c4f7175a8a5a585de84e8ff93976ce393efa5f2837aab1"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3997c7839262f4ef12cf90b818d6340c18e80f263f1a94bf157d0ec4420380e"
+dependencies = [
+ "bumpalo",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc1b4cb0cc549fcf58d7dfc081778139b3d283a081644e833e84682ad71cea24"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
 name = "winapi"
 version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -521,12 +667,65 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
+name = "windows-core"
+version = "0.62.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8e83a14d34d0623b51dce9581199302a221863196a1dde71a7663a4c2be9deb"
+dependencies = [
+ "windows-implement",
+ "windows-interface",
+ "windows-link",
+ "windows-result",
+ "windows-strings",
+]
+
+[[package]]
+name = "windows-implement"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "windows-interface"
+version = "0.59.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
 [[package]]
+name = "windows-result"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7781fa89eaf60850ac3d2da7af8e5242a5ea78d1a11c49bf2910bb5a73853eb5"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
+name = "windows-strings"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7837d08f69c77cf6b07689544538e017c1bfcf57e34b4c0ff58e6c2cd3b37091"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
 name = "windows-sys"
 version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -534,3 +733,9 @@ checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
  "windows-link",
 ]
+
+[[package]]
+name = "zmij"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29666d0abbfad1e3dc4dcf6144730dd3a3ab225bbbdac83319345b1b44ccfc1b"
diff --git a/Cargo.toml b/Cargo.toml
index 7b9fc39..0b3052f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,13 +1,20 @@
 [package]
 name = "mood"
 version = "0.1.0"
+description = "A music player governed by your moods."
 edition = "2024"
 
 [dependencies]
-derive_more = { version = "2.1.1", features = ["display"] }
+bincode = "=1.3.3"
+chrono = "0.4.45"
 directories = "6.0.0"
 expanduser = "1.2.2"
 rand = "0.10.2"
-ron = "0.12.2"
 serde = {version = "1.0.228", features = ["derive"] }
+serde_json = "1.0.150"
 walkdir = "2.5.0"
+
+[profile.release]
+strip = true
+lto = "thin"
+opt-level = 3
diff --git a/src/cli.rs b/src/cli.rs
new file mode 100644
index 0000000..f1563b3
--- /dev/null
+++ b/src/cli.rs
@@ -0,0 +1,60 @@
+use std::env;
+
+#[derive(Debug, PartialEq)]
+pub enum Action {
+    NewConfig,
+    NewState,
+    DumpTrajectory,
+    DumpLearner,
+    DumpAlbums,
+    Run,
+}
+
+const NAME: &str = env!("CARGO_PKG_NAME");
+const VERSION: &str = env!("CARGO_PKG_VERSION");
+const DESCRIPTION: &str = env!("CARGO_PKG_DESCRIPTION");
+
+fn print_help() {
+    println!(
+        "\
+        {NAME}: {DESCRIPTION}
+Usage: {NAME} [OPTION]
+
+Options:
+  --help            Show this help message.
+  --version         Show version information.
+  --new-config      Write a default config file and exit.
+  --new-state       Write a default state file and exit.
+  --dump-trajectory Dump the play trajectory as JSON to stdout.
+  --dump-learner    Dump learner weights as JSON to stdout.
+  --dump-albums     Dump album list from state as JSON to stdout.
+<no option>       Suggest and play the next album"
+    );
+}
+
+pub fn parse() -> Option<Action> {
+    let mut args = env::args();
+
+    let _binary_name = args.next();
+
+    match args.next().as_deref() {
+        None => Some(Action::Run),
+        Some("--help") | Some("-h") => {
+            print_help();
+            None
+        }
+        Some("--version") | Some("-V") | Some("-v") => {
+            println!("{NAME} {VERSION}");
+            None
+        }
+        Some("--new-config") => Some(Action::NewConfig),
+        Some("--new-state") => Some(Action::NewState),
+        Some("--dump-trajectory") => Some(Action::DumpTrajectory),
+        Some("--dump-learner") => Some(Action::DumpLearner),
+        Some("--dump-albums") => Some(Action::DumpAlbums),
+        Some(unknown) => {
+            eprintln!("Unknown option: {unknown}");
+            std::process::exit(1);
+        }
+    }
+}
diff --git a/src/config.rs b/src/config.rs
index 0be1d09..f38b571 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,26 +1,44 @@
 use directories::{ProjectDirs, UserDirs};
 use serde::{Deserialize, Serialize};
+use std::fs;
+
+use expanduser::expanduser;
 
 #[derive(Serialize, Deserialize)]
 pub struct Config {
     pub music_roots: Vec<String>,
     pub audio_exts: Vec<String>,
     pub skip_window_secs: u64,
-    pub learning_rate: f32,
-    pub decay_rate: f32,
-    pub min_score_thresh: f32,
     pub temperature: f32,
+    pub low_weight: f32,
+    pub mid_weight: f32,
+    pub high_weight: f32,
+    pub max_weight: f32,
 }
 
-pub fn default_state_path() -> String {
+fn default_config_path() -> String {
+    let name = "mood.json";
     ProjectDirs::from("qualifier", "organisation", "mood")
-        .and_then(|pd| {
-            pd.config_dir()
-                .join("mood.ron")
-                .to_str()
-                .map(|x| x.to_string())
-        })
-        .unwrap_or("~/.config/mood/mood.ron".to_string())
+        .and_then(|pd| pd.config_dir().join(name).to_str().map(|x| x.to_string()))
+        .unwrap_or(format!("~/.config/mood/{name}"))
+}
+
+impl Config {
+    pub fn try_load() -> Result<Config, String> {
+        expanduser(default_config_path())
+            .map_err(|e| e.to_string())
+            .and_then(|p| fs::read_to_string(p).map_err(|e| e.to_string()))
+            .and_then(|contents| serde_json::from_str(&contents).map_err(|e| e.to_string()))
+    }
+
+    pub fn try_save(&self) -> Result<(), String> {
+        let path = expanduser(default_config_path()).map_err(|e| e.to_string())?;
+        _ = path.parent().map(std::fs::create_dir_all);
+        let serialised = serde_json::to_string_pretty(self)
+            .map_err(|e| format!("Failed to serialize config: {}", e))?;
+        fs::write(&path, serialised).map_err(|e| format!("Failed to write config file: {}", e))?;
+        Ok(())
+    }
 }
 
 impl Default for Config {
@@ -39,10 +57,11 @@ impl Default for Config {
                 .map(String::from)
                 .collect(),
             skip_window_secs: 60,
-            learning_rate: 0.1,
-            decay_rate: 0.001,
-            min_score_thresh: 1e-5,
             temperature: 0.6,
+            low_weight: 0.25,
+            mid_weight: 0.5,
+            high_weight: 0.75,
+            max_weight: 1.0,
         }
     }
 }
diff --git a/src/learner.rs b/src/learner.rs
index 91b24fe..59db567 100644
--- a/src/learner.rs
+++ b/src/learner.rs
@@ -5,24 +5,15 @@ use serde::{Deserialize, Serialize};
 
 use crate::{config::Config, trajectory::Action};
 
-fn key(a: &str, b: &str) -> (String, String) {
-    let a = a.to_string();
-    let b = b.to_string();
-    if a < b { (a, b) } else { (b, a) }
-}
-
-fn compute_sum(
-    cand: &str,
-    known_keys: &HashSet<&String>,
-    map: &HashMap<(String, String), f32>,
-) -> f32 {
-    known_keys
-        .iter()
-        .filter_map(|k| map.get(&key(k, cand)))
-        .sum()
+fn compute_weight(past: &HashSet<String>, now: &HashSet<&String>) -> f32 {
+    let inter = now.iter().filter(|&&p| past.contains(p)).count();
+    if inter == 0 {
+        return 0.0;
+    }
+    (inter as f32) / ((now.len() as f32).sqrt() * (past.len() as f32).sqrt())
 }
 
-fn softmax_sample(items: &[(&String, f32)], temperature: f32) -> Option<(String, f32)> {
+fn softmax_sample(items: &[(String, f32)], temperature: f32) -> Option<(String, f32)> {
     if items.is_empty() {
         return None;
     }
@@ -35,7 +26,7 @@ fn softmax_sample(items: &[(&String, f32)], temperature: f32) -> Option<(String,
 
     let exp_values: Vec<_> = items
         .iter()
-        .map(|&(k, val)| (k, ((val - max_val) / temperature).exp()))
+        .map(|(k, val)| (k, ((val - max_val) / temperature).exp()))
         .collect();
 
     let sum: f32 = exp_values.iter().map(|(_, v)| *v).sum();
@@ -48,80 +39,79 @@ fn softmax_sample(items: &[(&String, f32)], temperature: f32) -> Option<(String,
         .ok()
 }
 
+#[derive(Serialize, Deserialize)]
+enum Episode {
+    Continue {
+        group: HashSet<String>,
+        avoid: Option<String>,
+        committed: String,
+    },
+    Escape {
+        from: HashSet<String>,
+        to: String,
+        committed: String,
+    },
+}
+
+impl Episode {
+    fn prune_mut(&mut self, valid: &HashSet<String>) -> bool {
+        match self {
+            Episode::Continue { group, avoid, .. } => {
+                if let Some(a) = avoid
+                    && valid.contains(a)
+                {
+                } else {
+                    *avoid = None;
+                };
+                group.retain(|g| valid.contains(g));
+                !group.is_empty()
+            }
+            Episode::Escape { from, to, .. } => {
+                if !valid.contains(to) {
+                    return false;
+                };
+                from.retain(|f| valid.contains(f));
+                !from.is_empty()
+            }
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Default)]
 pub struct Learner {
-    similar: HashMap<(String, String), f32>,
-    different: HashMap<(String, String), f32>,
+    history: Vec<Episode>,
 }
 
-#[derive(Debug)]
 pub enum Learning {
-    SkipExtend,
-    MoreExtend(Vec<String>, String),
     SkipToMore(Vec<String>, String),
     MoreToSkip(Vec<String>, String),
 }
 
 impl Learner {
     pub fn prune(&mut self, valid: &HashSet<String>) {
-        self.similar
-            .retain(|(a, b), _v| valid.contains(a) && valid.contains(b));
-        self.different
-            .retain(|(a, b), _v| valid.contains(a) && valid.contains(b));
+        self.history.retain_mut(|e| e.prune_mut(valid));
     }
+}
 
-    pub fn learn(&mut self, config: &Config, learning: &Learning) {
-        // global decay
-        for (_k, v) in self.similar.iter_mut().chain(self.different.iter_mut()) {
-            *v *= 1.0 - config.decay_rate;
-        }
-        // update
+impl Learner {
+    pub fn learn(&mut self, learning: &Learning) {
+        let stamp = chrono::Utc::now().format("U%Y%m%d-%H%M%S").to_string();
         match learning {
-            Learning::SkipExtend => {
-                // This is the least information carrying case, it does not
-                // follow that the trajectory contains similar or different
-                // items, we may simply be seeking something in particular.
-            }
-            Learning::MoreExtend(trajectory, new) => {
-                // We're continuing a good run so `new` is similar to everything
-                // in `trajectory`, but to account for the possibilty that our
-                // mood has changed over the course of this streak we damp
-                // sub-linearly that update by a proxy of temporal distance.
-                for (distance, e) in trajectory.iter().rev().enumerate() {
-                    let damp = ((distance + 1) as f32).powf(-0.5);
-                    let v = self.similar.entry(key(e, new)).or_default();
-                    *v = (1.0 - config.learning_rate) * *v + config.learning_rate * damp;
-                }
-            }
             Learning::SkipToMore(trajectory, new) => {
-                // We have learnt that `new` is different to everything in
-                // `trajectory`, the strongest signal we have.
-                for e in trajectory {
-                    let v = self.different.entry(key(e, new)).or_default();
-                    *v = (1.0 - config.learning_rate) * *v + config.learning_rate;
-                }
+                self.history.push(Episode::Escape {
+                    from: trajectory.iter().map(String::clone).collect(),
+                    to: new.clone(),
+                    committed: stamp,
+                });
             }
             Learning::MoreToSkip(trajectory, new) => {
-                // `new` could be different to everything in `trajectory`, or we
-                // simply changed our minds, so we have only weak evidence of
-                // difference. The positive coherence of trajectory was taken
-                // care of during MoreExtend above.
-                let damp = (trajectory.len() + 1) as f32;
-                for e in trajectory {
-                    let v = self.different.entry(key(e, new)).or_default();
-                    *v = (1.0 - config.learning_rate) * *v + config.learning_rate / damp;
-                }
+                self.history.push(Episode::Continue {
+                    group: trajectory.iter().map(String::clone).collect(),
+                    avoid: Some(new.clone()),
+                    committed: stamp,
+                });
             }
         };
-        // global threshold drop
-        self.similar = self
-            .similar
-            .extract_if(|_k, v| (*v).abs() > config.min_score_thresh)
-            .collect();
-        self.different = self
-            .different
-            .extract_if(|_k, v| (*v).abs() > config.min_score_thresh)
-            .collect();
     }
 
     pub fn sample(
@@ -129,10 +119,9 @@ impl Learner {
         trajectory: &[String],
         action: &Action,
         candidates: &HashSet<String>,
-        temperature: f32,
+        config: &Config,
     ) -> Option<(String, f32)> {
         let trajectory: HashSet<_> = trajectory.iter().collect();
-        let normalisation: f32 = f32::max(trajectory.len() as f32, 1.0);
 
         let candidates: Vec<_> = candidates
             .iter()
@@ -143,19 +132,57 @@ impl Learner {
             return None;
         }
 
-        let items = candidates
-            .iter()
-            .map(|&c| {
-                let sim = compute_sum(c, &trajectory, &self.similar);
-                let dif = compute_sum(c, &trajectory, &self.different);
-                let score = match action {
-                    Action::Skip => dif - sim,
-                    Action::More => sim - dif,
-                };
-                (c, score / normalisation)
-            })
-            .collect::<Vec<_>>();
+        let mut items: HashMap<String, f32> =
+            candidates.into_iter().map(|c| (c.clone(), 0.0)).collect();
+
+        for episode in self.history.iter() {
+            match (episode, action) {
+                (Episode::Escape { from, to, .. }, Action::Skip) => {
+                    let w = compute_weight(from, &trajectory);
+                    if let Some(to_w) = items.get_mut(to) {
+                        *to_w += config.max_weight * w;
+                    }
+                    for f in from {
+                        if let Some(from_weight) = items.get_mut(f) {
+                            *from_weight -= config.mid_weight * w;
+                        }
+                    }
+                }
+                (Episode::Escape { from, to, .. }, Action::More) => {
+                    let w = compute_weight(from, &trajectory);
+                    if trajectory.contains(to) {
+                        for f in from {
+                            if let Some(f_w) = items.get_mut(f) {
+                                *f_w -= config.low_weight * w;
+                            }
+                        }
+                    }
+                }
+                (Episode::Continue { group, avoid, .. }, Action::More) => {
+                    let w = compute_weight(group, &trajectory);
+                    for g in group {
+                        if let Some(g_w) = items.get_mut(g) {
+                            *g_w += config.max_weight * w;
+                        }
+                    }
+                    if let Some(a) = avoid
+                        && let Some(a_w) = items.get_mut(a)
+                    {
+                        *a_w -= config.low_weight * w;
+                    }
+                }
+                (Episode::Continue { group, .. }, Action::Skip) => {
+                    let w = compute_weight(group, &trajectory);
+                    for g in group {
+                        if let Some(v) = items.get_mut(g) {
+                            *v -= config.high_weight * w;
+                        }
+                    }
+                }
+            }
+        }
 
-        softmax_sample(&items, temperature)
+        let pairs: Vec<_> = items.into_iter().collect();
+        softmax_sample(&pairs, config.temperature)
     }
 }
diff --git a/src/main.rs b/src/main.rs
index 74f90c8..86c6341 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,61 +1,135 @@
-use std::process::Command;
+use std::{process::Command, process::exit};
 
+mod cli;
 mod config;
 mod learner;
 mod state;
 mod trajectory;
 
-use crate::{config::default_state_path, state::State};
+use crate::cli::{Action, parse};
+use crate::config::Config;
+use crate::state::State;
 
 fn mpc_load_and_play(path: &str) {
-    _ = Command::new("mpc")
-        .arg("clear")
-        .output()
-        .expect("failed to execute mpc clear");
-
-    _ = Command::new("mpc")
-        .args(["add", path])
-        .output()
-        .expect("failed to execute mpc add");
-
-    _ = Command::new("mpc")
-        .arg("play")
-        .output()
-        .expect("failed to execute mpc play");
+    _ = Command::new("mpc").arg("clear").output();
+
+    _ = Command::new("mpc").args(["add", path]).output();
+
+    _ = Command::new("mpc").arg("play").output();
 }
 
 fn notify(text: &str) {
     if let Err(e) = Command::new("notify-send")
-        .args(["-t", "5000", "-a", "mood", &text])
+        .args(["-t", "5000", "-a", "mood", text])
         .status()
     {
         eprintln!("Failed to show notification: {e}");
     }
 }
 
+fn load_state_no_default() -> State {
+    State::try_load().unwrap_or_else(|e| {
+        eprintln!("Failed to load state: {e}, nothing to dump.");
+        exit(1);
+    })
+}
+
 fn main() {
-    let state = State::load(&default_state_path());
-    let mut state = match state {
-        Err(e) => {
-            eprintln!("Failed to load state: {e}");
-            State::default()
-        }
-        Ok(s) => s,
+    let action = parse();
+    if action.is_none() {
+        return;
     };
 
-    let ur = state.update_albums();
-    println!("Update result: {ur}");
+    let action = action.unwrap();
 
-    if let Some((next_album, prob)) = state.next() {
-        let text = format!("Now playing: {next_album} ({:.2}%)", prob * 100.0);
-        println!("{text}");
-        mpc_load_and_play(&next_album);
-        notify(&text);
-    } else {
-        println!("No next album available.");
-    }
+    match action {
+        Action::DumpAlbums => {
+            let state = load_state_no_default();
+            println!(
+                "{}",
+                state.dump_albums().unwrap_or_else(|e| {
+                    eprintln!("Failed to serialize state (dump-albums): {e}");
+                    exit(1);
+                })
+            );
+        }
+
+        Action::DumpLearner => {
+            let state = load_state_no_default();
+            println!(
+                "{}",
+                state.dump_learner().unwrap_or_else(|e| {
+                    eprintln!("Failed to serialize state (dump-learner): {e}");
+                    exit(1);
+                })
+            );
+        }
+
+        Action::DumpTrajectory => {
+            let state = load_state_no_default();
+            println!(
+                "{}",
+                state.dump_trajectory().unwrap_or_else(|e| {
+                    eprintln!("Failed to serialize state (dump-trajectory): {e}");
+                    exit(1);
+                })
+            );
+        }
+
+        Action::NewState => {
+            let default = State::default();
+            if let Err(e) = default.try_save() {
+                eprintln!("Failed to write new state: {e}");
+                exit(1);
+            }
+            println!("New state written.");
+        }
+
+        Action::NewConfig => {
+            let default = Config::default();
+            if let Err(e) = default.try_save() {
+                eprintln!("Failed to write new config: {e}");
+                exit(1);
+            }
+            println!("New config written.");
+        }
 
-    if let Err(e) = state.try_save() {
-        eprintln!("Failed to save state: {e}");
+        Action::Run => {
+            let config = match Config::try_load() {
+                Ok(c) => c,
+                Err(e) => {
+                    eprintln!("Failed to load config: {e}, writing defaults.");
+                    let default = Config::default();
+                    if let Err(se) = default.try_save() {
+                        panic!("Failed to save default config: {se}");
+                    }
+                    default
+                }
+            };
+
+            let mut state = match State::try_load() {
+                Ok(s) => s,
+                Err(e) => {
+                    eprintln!("Failed to load state: {e}");
+                    State::default()
+                }
+            };
+
+            let ur = state.update_albums(&config);
+            println!("Update result: {ur}");
+
+            if let Some((next_album, prob)) = state.next(&config) {
+                let text = format!("Now playing: {next_album} ({:.2}%)", prob * 100.0);
+                println!("{text}");
+                mpc_load_and_play(&next_album);
+                notify(&text);
+            } else {
+                println!("No next album available.");
+            }
+
+            if let Err(e) = state.try_save() {
+                panic!("Failed to save state: {e}");
+            }
+        }
     }
 }
diff --git a/src/state.rs b/src/state.rs
index b9a6618..a04412f 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -1,36 +1,36 @@
-use std::{collections::HashSet, fs};
-
-use derive_more::Display;
+use std::{collections::HashSet, fmt, fs};
+use directories::ProjectDirs;
 use expanduser::expanduser;
 use serde::{Deserialize, Serialize};
 use walkdir::WalkDir;
 
-use crate::{
-    config::{Config, default_state_path},
-    learner::Learner,
-    trajectory::Trajectory,
-};
+use crate::{config::Config, learner::Learner, trajectory::Trajectory};
+
+fn default_state_path() -> String {
+    let name = "mood.bin";
+    ProjectDirs::from("qualifier", "organisation", "mood")
+        .and_then(|pd| pd.config_dir().join(name).to_str().map(|x| x.to_string()))
+        .unwrap_or(format!("~/.config/mood/{name}"))
+}
 
 #[derive(Serialize, Deserialize, Default)]
 pub struct State {
-    pub config: Config,
     trajectory: Trajectory,
     learner: Learner,
     albums: HashSet<String>,
 }
 
 impl State {
-    pub fn next(&mut self) -> Option<(String, f32)> {
-        let learning = self.trajectory.step(self.config.skip_window_secs);
+    pub fn next(&mut self, config: &Config) -> Option<(String, f32)> {
+        let learning = self.trajectory.step(config.skip_window_secs);
         if let Some(ref learning) = learning {
-            println!("Obtained learning: {learning:?}");
-            self.learner.learn(&self.config, learning);
+            self.learner.learn(learning);
         }
         if let Some((new_album, prob)) = self.learner.sample(
             self.trajectory.slice(),
             &learning.as_ref().into(),
             &self.albums,
-            self.config.temperature,
+            config,
         ) {
             self.trajectory.log(&new_album);
             Some((new_album, prob))
@@ -40,36 +40,39 @@ impl State {
     }
 }
 
-#[derive(Display)]
-#[display("+{added}/-{removed}, total {new_total}")]
 pub struct UpdateResult {
     added: usize,
     removed: usize,
     new_total: usize,
 }
 
+impl fmt::Display for UpdateResult {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "+{}/-{}, total {}", self.added, self.removed, self.new_total)
+    }
+}
+
 impl State {
-    pub fn load(path: &str) -> Result<State, String> {
-        expanduser(path)
+    pub fn try_load() -> Result<State, String> {
+        expanduser(default_state_path())
             .map_err(|e| e.to_string())
-            .and_then(|p| fs::read_to_string(p).map_err(|e| e.to_string()))
-            .and_then(|contents| ron::from_str(&contents).map_err(|e| e.to_string()))
+            .and_then(|p| fs::read(p).map_err(|e| e.to_string()))
+            .and_then(|contents| bincode::deserialize(&contents).map_err(|e| e.to_string()))
     }
 
     pub fn try_save(&self) -> Result<(), String> {
         let str_path = default_state_path();
         let path = expanduser(&str_path).map_err(|e| e.to_string())?;
-        _ = path.parent().map(|parent| std::fs::create_dir_all(parent));
-        let serialised = ron::ser::to_string_pretty(self, ron::ser::PrettyConfig::default())
-            .map_err(|e| format!("Failed to serialize state: {}", e))?;
+        _ = path.parent().map(std::fs::create_dir_all);
+        let serialised =
+            bincode::serialize(self).map_err(|e| format!("Failed to serialize state: {}", e))?;
         fs::write(&path, serialised)
             .map_err(|e| format!("Failed to write state file at {}: {}", str_path, e))?;
         Ok(())
     }
 
-    pub fn update_albums(&mut self) -> UpdateResult {
-        let roots: Vec<_> = self
-            .config
+    pub fn update_albums(&mut self, config: &Config) -> UpdateResult {
+        let roots: Vec<_> = config
             .music_roots
             .iter()
             .filter_map(|x| expanduser(x).ok().filter(|p| p.is_dir()))
@@ -77,14 +80,14 @@ impl State {
 
         let mut new_albums: HashSet<String> = HashSet::new();
 
-        for root_path in roots {
+        for root_path in &roots {
             for entry in WalkDir::new(&root_path) {
                 let entry = match entry {
                     Ok(e) if e.path().is_dir() => e,
                     _ => continue,
                 };
 
-                if !self.contains_audio(&entry) {
+                if !Self::contains_audio(&entry, config) {
                     continue;
                 }
 
@@ -113,21 +116,35 @@ impl State {
         }
     }
 
-    fn contains_audio(&self, entry: &walkdir::DirEntry) -> bool {
+    fn contains_audio(entry: &walkdir::DirEntry, config: &Config) -> bool {
         fs::read_dir(entry.path()).ok().is_some_and(|mut entries| {
             entries.any(|e| {
                 e.as_ref()
-                    .is_ok_and(|entry| self.is_audio_file(&entry.path()))
+                    .is_ok_and(|entry| Self::is_audio_file(&entry.path(), config))
             })
         })
     }
 
-    fn is_audio_file(&self, path: &std::path::Path) -> bool {
+    fn is_audio_file(path: &std::path::Path, config: &Config) -> bool {
         !path.is_dir()
             && path
                 .extension()
                 .and_then(|ext| ext.to_str())
                 .map(|s| s.to_lowercase())
-                .is_some_and(|ext| self.config.audio_exts.contains(&format!(".{ext}")))
+                .is_some_and(|ext| config.audio_exts.contains(&format!(".{ext}")))
+    }
+}
+
+impl State {
+    pub fn dump_albums(&self) -> Result<String, String> {
+        serde_json::to_string_pretty(&self.albums).map_err(|e| e.to_string())
+    }
+
+    pub fn dump_learner(&self) -> Result<String, String> {
+        serde_json::to_string_pretty(&self.learner).map_err(|e| e.to_string())
+    }
+
+    pub fn dump_trajectory(&self) -> Result<String, String> {
+        serde_json::to_string_pretty(&self.trajectory).map_err(|e| e.to_string())
     }
 }
diff --git a/src/trajectory.rs b/src/trajectory.rs
index 214e16c..cbb0661 100644
--- a/src/trajectory.rs
+++ b/src/trajectory.rs
@@ -3,7 +3,7 @@ use std::{collections::HashSet, time::SystemTime};
 
 use crate::learner::Learning;
 
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize)]
 struct LastData {
     timestamp: SystemTime,
     album: String,
@@ -16,7 +16,7 @@ pub struct Trajectory {
     history: Vec<String>,
 }
 
-#[derive(Serialize, Deserialize, Clone, PartialEq, Debug)]
+#[derive(Serialize, Deserialize, Clone, PartialEq)]
 pub enum Action {
     Skip,
     More,
@@ -26,8 +26,8 @@ impl From<Option<&Learning>> for Action {
     fn from(learning: Option<&Learning>) -> Action {
         if let Some(ts) = learning {
             match ts {
-                Learning::SkipExtend | Learning::MoreToSkip(_, _) => Action::Skip,
-                Learning::MoreExtend(_, _) | Learning::SkipToMore(_, _) => Action::More,
+                Learning::MoreToSkip(_, _) => Action::Skip,
+                Learning::SkipToMore(_, _) => Action::More,
             }
         } else {
             Action::Skip
@@ -71,26 +71,29 @@ impl Trajectory {
 
             let last_album = last_data.album.clone();
             let current_streak = self.history.clone();
+            let learnt_nothing = self
+                .streak_kind
+                .as_ref()
+                .map(|kind| *kind == action)
+                .unwrap_or(false);
 
-            let learning = if let Some(ref kind) = self.streak_kind
-                && kind == &action
-            {
-                self.history.push(last_album.clone());
-                match action {
-                    Action::Skip => Learning::SkipExtend,
-                    Action::More => Learning::MoreExtend(current_streak, last_album),
+            let learning = match (learnt_nothing, &action) {
+                (false, Action::Skip) => {
+                    Some(Learning::MoreToSkip(current_streak, last_album.clone()))
                 }
-            } else {
-                self.history.clear();
-                self.history.push(last_album.clone());
-                match action {
-                    Action::Skip => Learning::MoreToSkip(current_streak, last_album),
-                    Action::More => Learning::SkipToMore(current_streak, last_album),
+                (false, Action::More) => {
+                    Some(Learning::SkipToMore(current_streak, last_album.clone()))
                 }
+                _ => None,
+            };
+
+            if !learnt_nothing {
+                self.history.clear();
             };
+            self.history.push(last_album);
 
             self.streak_kind = Some(action);
-            Some(learning)
+            learning
         } else {
             None
         }