// 記憶、技能、範本 (the original: user bot memories, agent skills and template skills/bots).
// - Memories belong to a bot: facts it was asked to keep across chats.
// - Skills are shared, named procedures; the bot sees their names and loads one when it needs it.
// - Templates start a new bot with a ready role and instructions.

use serde::{Deserialize, Serialize};

/// Most memories a bot keeps; the oldest go first (estimated).
pub const MAX_MEMORIES: usize = 200;
/// Longest memory (estimated).
pub const MAX_MEMORY_CHARS: usize = 500;

#[derive(Clone, Serialize, Deserialize, Debug, PartialEq)]
pub struct Skill {
    pub name: String,
    pub description: String,
    pub instructions: String,
}

pub struct Template {
    pub name: &'static str,
    pub description: &'static str,
    pub instructions: &'static str,
    pub shape: &'static str,
    pub color: &'static str,
}

pub const TEMPLATES: [Template; 5] = [
    Template { name: "研究助理", description: "上網找資料、整理重點、附上來源", instructions: "先釐清問題，再用 web_fetch 或瀏覽器找至少兩個可靠來源。回答先給結論，再列重點，每個重點附來源網址。不確定的地方直接說不確定。", shape: "circle", color: "green" },
    Template { name: "寫作夥伴", description: "幫你構思、改寫和潤稿", instructions: "先問清楚讀者和語氣。改稿時保留作者的意思，列出改了什麼和為什麼。用繁體中文、台灣用語。", shape: "cloud", color: "purple" },
    Template { name: "電腦助手", description: "在自己的電腦上跑指令、整理檔案、操作網頁", instructions: "預設在你自己的電腦上做事。動手前先看清楚（list_dir、read_file、截圖），每一步確認結果。要動到使用者的 Mac 時先說明要做什麼。", shape: "gem", color: "blue" },
    Template { name: "客服助理", description: "在 Slack、Discord、Telegram 或 Teams 回覆客人", instructions: "回答簡短、有禮貌。不確定的事不要編，說會請同事確認。不要透露內部資料或使用者的私人資訊。", shape: "pill", color: "orange" },
    Template { name: "開發助手", description: "看程式、跑測試、追 GitHub 上的事", instructions: "改程式前先讀相關檔案和測試。每次修改後跑測試，回報結果。PR 或 CI 的事件來時，先看紀錄再下結論。", shape: "hexagon", color: "black" },
];

/// Add a memory (no duplicates; the oldest drop off past the limit).
pub fn remember(list: &mut Vec<String>, fact: &str) -> Result<String, String> {
    let f: String = fact.trim().chars().take(MAX_MEMORY_CHARS).collect();
    if f.is_empty() {
        return Err("要記住什麼？".into());
    }
    if list.iter().any(|m| m == &f) {
        return Ok(format!("已經記得：{f}"));
    }
    list.push(f.clone());
    let n = list.len();
    if n > MAX_MEMORIES {
        list.drain(..n - MAX_MEMORIES);
    }
    Ok(format!("記住了：{f}"))
}

/// Forget by number (1-based) or by text it contains.
pub fn forget(list: &mut Vec<String>, what: &str) -> Result<String, String> {
    let w = what.trim();
    let idx = match w.parse::<usize>() {
        Ok(n) if n >= 1 && n <= list.len() => Some(n - 1),
        _ => list.iter().position(|m| !w.is_empty() && m.contains(w)),
    };
    match idx {
        Some(i) => Ok(format!("忘記了：{}", list.remove(i))),
        None => Err(format!("沒有記得「{w}」這件事")),
    }
}

/// Add a skill, or replace the one with the same name. True when it is new.
pub fn upsert_skill(list: &mut Vec<Skill>, k: Skill) -> bool {
    match list.iter_mut().find(|x| x.name == k.name) {
        Some(x) => {
            *x = k;
            false
        }
        None => {
            list.push(k);
            true
        }
    }
}

// ---------- 自己進化: a job's way that worked becomes a skill ----------
// The bot forgot everything between chats: a post with a picture on Threads took it 39 steps,
// and the next one would have taken as many. After a longer job the model looks back at the
// steps and writes down the short path that worked (or improves the skill it followed); the
// next time it reads that first.

/// Steps on computers and pages a job needs before it is worth looking back on (estimated).
pub const LEARN_MIN_STEPS: usize = 5;
/// Longest learned skill (estimated; a skill is read whole before each such job).
const MAX_SKILL_CHARS: usize = 4000;

/// A turn that did enough real work, and didn't already save a skill itself.
pub fn worth_learning(turn: &[crate::model::Message]) -> bool {
    let calls: Vec<&str> = turn.iter().flat_map(|m| m.tool_calls.iter().map(|c| c.name.as_str())).collect();
    !calls.contains(&"save_skill") && calls.iter().filter(|n| !crate::appctl::is_app_tool(n) && **n != "react").count() >= LEARN_MIN_STEPS
}

pub const LEARN_SYSTEM: &str = "你在幫一個會操作電腦的 Bot 整理經驗，讓它下次做同樣的事更快、不再犯同樣的錯。下面是它剛做完的一件事：使用者的要求、每一步和結果、最後的回覆，還有它已經有的技能。

先判斷要不要存。使用者希望它從做過的事學會、下次不用重新摸索：只要這件事是在某個網站或程式上動手操作（填表、發文、回留言、按讚、上傳下載、改設定、跑一套固定的檢查），就要存，就算這次只做了一次。只有閒聊、單純回答問題、只是查資料讀內容，才不用存。這次沒做成功的，不要存成做法；但如果已經有這件事的技能，可以把「這樣做行不通」補進去。

要存的話，寫一份「下次照著做就會成功」的技能：
- 寫這次真的成功的那條最短路徑，一步一行，寫出用哪個工具、在哪台電腦、哪個網址或程式（每一步結果開頭 [ ] 裡的名字，就是那一步用的電腦）。
- 繞路和失敗的嘗試不要寫成步驟；把「哪裡會卡、要怎麼避開」寫成「注意：」。
- 用畫面上看得到的名字指東西（例如 browser_click 的 text 寫「Attach media」、browser_type 的 text 寫欄位名「Customer name」），不要寫元素編號或座標，那些每次都會變。browser_open 的結果就有這一頁的元素清單，不用另外截圖。
- 寫通用的做法，不要寫這次的內容（這篇文的文字、這張圖的檔名）；使用者表達過的偏好（語氣、格式、一定要附圖、用哪台電腦）要寫進去。
- 已經有做同一件事的技能，就用同一個名稱，把舊的和這次學到的合併成更好的一版：舊的對的保留，錯的改掉。這次照著技能做而且很順，就不用再存。

只回一個 JSON，不要別的字：
不用存：{\"save\": false, \"why\": \"一句話說為什麼\"}
要存：{\"save\": true, \"name\": \"短名稱\", \"description\": \"一行：什麼時候用\", \"instructions\": \"做法\"}";

fn cut(s: &str, n: usize) -> String {
    let flat = s.split_whitespace().collect::<Vec<_>>().join(" ");
    if flat.chars().count() <= n { flat } else { format!("{}…", flat.chars().take(n).collect::<String>()) }
}

/// What the model looks back on: the request, each step with its result, the answer and the
/// skills there are.
pub fn learn_brief(turn: &[crate::model::Message], skills: &[Skill]) -> String {
    use crate::model::Role;
    let mut steps: Vec<String> = vec![];
    for (i, m) in turn.iter().enumerate() {
        if m.role == Role::User && i > 0 {
            steps.push(format!("（使用者中途說：{}）", cut(&m.text, 300)));
        }
        for c in &m.tool_calls {
            let result = turn.iter().find(|r| r.role == Role::Tool && r.tool_call_id == c.id).map(|r| r.text.as_str()).unwrap_or("");
            let failed = if c.status == crate::model::ToolStatus::Failed { "（失敗）" } else { "" };
            steps.push(format!("{} {} → {}{failed}", c.name, cut(&c.args, 160), cut(result, 220)));
        }
    }
    const KEEP: usize = 40;
    if steps.len() > KEEP * 2 {
        let gone = steps.len() - KEEP * 2;
        steps.splice(KEEP..steps.len() - KEEP, [format!("…（中間省略 {gone} 步）…")]);
    }
    let ask = turn.first().map(|m| cut(&m.text, 800)).unwrap_or_default();
    let answer = turn.iter().rev().find(|m| m.role == crate::model::Role::Assistant && !m.text.trim().is_empty()).map(|m| cut(&m.text, 600)).unwrap_or_default();
    let mut s = format!("使用者的要求：\n{ask}\n\n每一步（工具 參數 → 結果）：\n");
    for (i, st) in steps.iter().enumerate() {
        s.push_str(&format!("{}. {st}\n", i + 1));
    }
    s.push_str(&format!("\n最後的回覆：\n{answer}\n\n已經有的技能："));
    if skills.is_empty() {
        s.push_str("（沒有）");
    }
    let mut room = 8000usize;
    for k in skills {
        let body = cut(&k.instructions, 2000.min(room));
        room = room.saturating_sub(body.chars().count());
        s.push_str(&format!("\n- {}：{}\n  做法：{body}", k.name, k.description));
    }
    s
}

/// The skill in the model's answer, when it chose to save one.
pub fn learned_skill(text: &str) -> Option<Skill> {
    let t = text.trim();
    let json = t.find('{').and_then(|a| t.rfind('}').filter(|b| *b >= a).map(|b| &t[a..=b]))?;
    let v: serde_json::Value = serde_json::from_str(json).ok()?;
    if v["save"].as_bool() != Some(true) {
        return None;
    }
    let name: String = v["name"].as_str()?.trim().chars().take(40).collect();
    let instructions: String = v["instructions"].as_str()?.trim().chars().take(MAX_SKILL_CHARS).collect();
    if name.is_empty() || instructions.is_empty() {
        return None;
    }
    Some(Skill { name, description: v["description"].as_str().unwrap_or("").trim().chars().take(120).collect(), instructions })
}

/// The line under the bot's reply that says it learned (or improved) a skill.
pub fn learned_note(name: &str, fresh: bool) -> String {
    if fresh {
        format!("\n\n（學會了新做法「{name}」，下次做這件事會照著做。）")
    } else {
        format!("\n\n（把做法「{name}」更新了，下次會照新的做。）")
    }
}

pub fn prompt_section(memories: &[String], skills: &[Skill]) -> String {
    let mut s = String::new();
    if !memories.is_empty() {
        s.push_str("\n\n你記得的事（使用者要你記住的；用 remember 新增、forget 刪除）：\n");
        for (i, m) in memories.iter().enumerate() {
            s.push_str(&format!("{}. {m}\n", i + 1));
        }
    } else {
        s.push_str("\n\n使用者說「記住…」「以後都…」時，用 remember 記下來；說「忘記…」時用 forget。");
    }
    if !skills.is_empty() {
        s.push_str("\n\n你會的技能（以前做成功的做法）。開始做一件事之前先看這裡：有符合的，先用 use_skill 讀出完整做法再照著做，不要重新摸索：\n");
        for k in skills {
            s.push_str(&format!("- {}：{}\n", k.name, k.description));
        }
    }
    s.push_str("\n使用者教你一套可以重複用的做法時，可以用 save_skill 存成技能，所有 Bot 都能用。");
    s
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn remember_and_forget() {
        let mut m = vec![];
        assert!(remember(&mut m, "我喜歡靠窗的座位").unwrap().starts_with("記住了"));
        assert!(remember(&mut m, "我喜歡靠窗的座位").unwrap().starts_with("已經記得"));
        remember(&mut m, "週五不開會").unwrap();
        assert_eq!(forget(&mut m, "1").unwrap(), "忘記了：我喜歡靠窗的座位");
        assert!(forget(&mut m, "不存在").is_err());
        assert_eq!(forget(&mut m, "週五").unwrap(), "忘記了：週五不開會");
        for i in 0..(MAX_MEMORIES + 5) {
            remember(&mut m, &format!("事 {i}")).unwrap();
        }
        assert_eq!(m.len(), MAX_MEMORIES);
        assert_eq!(m[0], "事 5");
        let p = prompt_section(&m[..1], &[Skill { name: "週報".into(), description: "整理每週進度".into(), instructions: "…".into() }]);
        assert!(p.contains("1. 事 5") && p.contains("- 週報：整理每週進度") && p.contains("use_skill"));
    }

    fn call(id: &str, name: &str, args: &str, failed: bool) -> crate::model::ToolCall {
        crate::model::ToolCall { id: id.into(), name: name.into(), args: args.into(), status: if failed { crate::model::ToolStatus::Failed } else { crate::model::ToolStatus::Done } }
    }

    fn result(id: &str, text: &str) -> crate::model::Message {
        crate::model::Message { role: crate::model::Role::Tool, tool_call_id: id.into(), text: text.into(), ..Default::default() }
    }

    /// A post with a picture: five real steps, one of them failed, the person corrects it midway.
    fn post_turn() -> Vec<crate::model::Message> {
        use crate::model::Message;
        let step = |c: crate::model::ToolCall| Message { tool_calls: vec![c], ..Message::assistant("", "b") };
        vec![
            Message::user("幫我發一篇 Threads，記得附圖"),
            step(call("1", "browser_open", r#"{"url":"https://www.threads.com/"}"#, false)),
            result("1", "已打開 https://www.threads.com/\n[13] 按鈕「Create」"),
            step(call("2", "browser_click", r#"{"ref":"13"}"#, false)),
            result("2", "已點 [13]。新出現的文字：New thread"),
            Message { steer: true, ..Message::user("語氣要輕鬆一點") },
            step(call("3", "browser_type", r#"{"ref":"12","value":"今天天氣好"}"#, false)),
            result("3", "已在 [12] 輸入。"),
            step(call("4", "browser_upload", r#"{"path":"/home/bot/x.jpg"}"#, true)),
            result("4", "這台電腦上沒有這個檔案"),
            step(call("5", "browser_upload", r#"{"path":"/home/bot/bot-6/附件/x.jpg"}"#, false)),
            result("5", "已把 /home/bot/bot-6/附件/x.jpg 放進上傳欄位。"),
            step(call("6", "remember", r#"{"fact":"x"}"#, false)),
            result("6", "記住了"),
            Message::assistant("發好了：https://www.threads.com/@me/post/1", "b"),
        ]
    }

    #[test]
    fn a_long_enough_job_is_looked_back_on() {
        let turn = post_turn();
        assert!(worth_learning(&turn));
        // App steps (remember) don't count; four real steps aren't enough.
        assert!(!worth_learning(&turn[..10]));
        // A job that saved a skill itself is left alone.
        let mut saved = turn.clone();
        saved[12].tool_calls[0].name = "save_skill".into();
        assert!(!worth_learning(&saved));
    }

    #[test]
    fn the_look_back_has_every_step_and_the_skills() {
        let skills = [Skill { name: "Threads 發文".into(), description: "在 Threads 發文".into(), instructions: "1. browser_open https://www.threads.com/".into() }];
        let b = learn_brief(&post_turn(), &skills);
        assert!(b.starts_with("使用者的要求：\n幫我發一篇 Threads，記得附圖"), "{b}");
        assert!(b.contains("1. browser_open {\"url\":\"https://www.threads.com/\"} → 已打開 https://www.threads.com/ [13] 按鈕「Create」"), "{b}");
        assert!(b.contains("（使用者中途說：語氣要輕鬆一點）"), "{b}");
        assert!(b.contains("browser_upload {\"path\":\"/home/bot/x.jpg\"} → 這台電腦上沒有這個檔案（失敗）"), "{b}");
        assert!(b.contains("最後的回覆：\n發好了"), "{b}");
        assert!(b.contains("- Threads 發文：在 Threads 發文\n  做法：1. browser_open"), "{b}");
        // A very long job keeps its start and its end.
        let mut long = vec![crate::model::Message::user("做很多事")];
        for i in 0..200 {
            long.push(crate::model::Message { tool_calls: vec![call(&i.to_string(), "browser_click", "{}", false)], ..crate::model::Message::assistant("", "b") });
        }
        let b = learn_brief(&long, &[]);
        assert!(b.contains("（中間省略 120 步）") && b.contains("81. browser_click") && !b.contains("82. "), "{b}");
    }

    #[test]
    fn a_learned_skill_is_read_from_the_answer() {
        let k = learned_skill("好的\n{\"save\": true, \"name\": \" Threads 發文附圖 \", \"description\": \"在 Threads 發一篇附圖的文\", \"instructions\": \"1. browser_open https://www.threads.com/\"}").unwrap();
        assert_eq!((k.name.as_str(), k.description.as_str()), ("Threads 發文附圖", "在 Threads 發一篇附圖的文"));
        assert!(learned_skill(r#"{"save": false}"#).is_none());
        assert!(learned_skill(r#"{"save": true, "name": "", "instructions": "x"}"#).is_none());
        assert!(learned_skill("不用存").is_none());
        assert!(learned_skill("} {").is_none());
        let mut list = vec![];
        assert!(upsert_skill(&mut list, k.clone()));
        assert!(!upsert_skill(&mut list, Skill { instructions: "新的".into(), ..k }));
        assert_eq!((list.len(), list[0].instructions.as_str()), (1, "新的"));
        assert!(learned_note("Threads 發文附圖", true).contains("學會了新做法「Threads 發文附圖」"));
    }
}