// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

import Quickshell
import Quickshell.Io
import Quickshell.Wayland
import QtQuick
import ".."
import "Files.js" as Files

// The assistant canvas: a view over desktop-assistant's socket. The daemon
// owns the model, the tools and the history; this keeps the conversation it
// was told about, so the card reopens where it was, and sends what is typed.
// Protocol: desktop-assistant, docs/superpowers/specs/2026-10-16-text-daemon-design.md.
Scope {
    id: root

    property string monitor: "DP-1"
    // The daemon's socket; a check against a scratch daemon points it elsewhere.
    property string socketPath: `${Quickshell.env("XDG_RUNTIME_DIR") || "/tmp"}/desktop-assistant.sock`
    property bool open: false
    property bool historyOpen: false
    property bool pickerOpen: false
    property string pickDir: ""           // where the picker opened last; "" is home

    // Files waiting to go with the next question: [{path, name, kind}].
    property var staged: []
    // Chat about it: the chat layout before any turn exists.
    property bool chatting: false
    // When the conversation last moved, for the resume rule in show().
    property double lastActive: 0

    // entry: one line. file: files staged, nothing asked yet. chat: turns.
    readonly property string mode: turns.count || root.chatting ? "chat"
                                 : root.staged.length ? "file" : "entry"
    // The Do row's operation: one at a time, either fileops (a Process) or
    // the daemon's write (To .md). Its result stays on the card.
    property string opLabel: ""
    property bool opRunning: false
    property bool opDaemon: false
    property int opChars: 0
    property var opOut: []
    property string opError: ""
    // Results folder: $(xdg-user-dir DOCUMENTS)/Assistant, read once.
    property string outDir: (Quickshell.env("HOME") || "") + "/Documents/Assistant"
    readonly property string fileops:
        decodeURIComponent(Qt.resolvedUrl("fileops").toString().replace(/^file:\/\//, ""))
    readonly property string mdPrompt: "Rewrite this document as Markdown: keep its wording; "
        + "use headings, lists and tables where the original has them; transcribe scanned "
        + "pages. Output only the Markdown."

    // A staged kind chat does not take holds the question back.
    readonly property bool blocked: root.staged.some(f => !Files.chats(f.kind))

    readonly property bool connected: link.item?.connected ?? false
    property string state: "idle"
    property string model: ""
    // The preferred model being loaded on open, shown in the header until
    // the router reports it loaded. Set from shell.qml.
    property string swapping: ""
    property int ctxUsed: 0
    property int ctxMax: 0
    property var convId: null
    property string notice: ""            // an error with no turn to hang it on
    property string runningTool: ""
    property var convs: []
    property var results: []
    readonly property bool busy: root.state !== "idle"

    // A daemon gone mid-reply sends no idle; its hello on return redraws.
    onConnectedChanged: if (!root.connected) {
        root.state = "idle";
        root.runningTool = "";
        if (root.opRunning && root.opDaemon) { root.opRunning = false; root.opError = "assistant gone"; }
    }

    // One row per turn. tools is a comma-joined string: a ListModel role
    // holding an array becomes a nested model, which a Repeater can read but
    // setProperty cannot append to.
    ListModel { id: turns }
    readonly property alias turnsModel: turns   // read by the load check harness

    // Tokens arrive faster than markdown is worth re-rendering, so they
    // collect here and reach the model on a 50 ms tick.
    property string bufReply: ""
    property string bufThink: ""

    readonly property var screenObj:
        Quickshell.screens.find(s => s.name === root.monitor) ?? Quickshell.screens[0]

    function toggle() { if (root.open) root.close(); else root.show(); }

    // A conversation idle for 10 minutes is over: opening starts a new one,
    // the old one staying in History. ponytail: a constant, not a setting.
    function show() {
        // Never while a reply runs: new would stop it, and a stopped turn is
        // not saved.
        if (turns.count && !root.busy && Date.now() - root.lastActive > 10 * 60 * 1000) root.fresh();
        root.open = true;
    }

    function close() { root.open = false; root.historyOpen = false; root.pickerOpen = false; }
    // Escape: the picker, then the history panel, then the card.
    function back() {
        if (root.pickerOpen) root.pickerOpen = false;
        else if (root.historyOpen) root.historyOpen = false;
        else root.close();
    }

    function fresh() {
        root.send({ type: "new" });
        root.chatting = false;
    }

    // A drop is a new task: a new conversation with these files staged.
    function attach(paths) {
        const files = paths.filter(p => p !== "").map(Files.file);
        if (!files.length) return;
        if (root.opRunning) root.stopOp();      // a drop is a new task
        root.fresh();
        root.clearOp();
        root.staged = files;
        root.historyOpen = root.pickerOpen = false;
        root.open = true;
        root.refine();
    }

    function stage(path) {
        if (root.staged.some(f => f.path === path)) return;
        root.staged = root.staged.concat([Files.file(path)]);
        root.refine();
    }

    function clearOp() {
        if (root.opRunning) return;
        root.opLabel = root.opError = "";
        root.opOut = [];
        root.opChars = 0;
    }

    function runOp(o) {
        if (root.opRunning || !root.staged.length) return;
        root.clearOp();
        root.opLabel = o.label;
        root.opRunning = true;
        const paths = root.staged.map(f => f.path);
        if (o.op === "md") {
            if (!root.connected) { root.opRunning = false; root.opError = "assistant not running"; return; }
            root.opDaemon = true;
            const name = root.staged[0].name.replace(/\.[^.]*$/, "") + ".md";
            root.send({ type: "write", files: paths, prompt: root.mdPrompt, dir: root.outDir, name: name });
        } else {
            root.opDaemon = false;
            // A Process per run: a stopped run's late answer must not be
            // read as the next run's.
            root.opProc = opRun.createObject(root, { command: [root.fileops, o.op, root.outDir].concat(paths) });
        }
    }

    property var opProc: null

    function stopOp() {
        if (!root.opRunning) return;
        if (root.opDaemon) root.send({ type: "stop" });
        else if (root.opProc) {
            root.opProc.running = false;   // fileops kills its tool, removes the partial
            root.opProc = null;
        }
        root.opRunning = false;
        root.opError = "stopped";
    }

    Component {
        id: opRun
        Process {
            id: proc
            running: true
            stdout: StdioCollector {
                onStreamFinished: {
                    if (root.opProc !== proc) { proc.destroy(); return; }   // stopped, or superseded
                    root.opProc = null;
                    root.opRunning = false;
                    try {
                        const r = JSON.parse(text.trim().split("\n").pop());
                        if (r.ok) root.opOut = r.out; else root.opError = r.error;
                    } catch (e) {
                        root.opError = "fileops gave no answer";
                    }
                    proc.destroy();
                }
            }
        }
    }

    Process {
        running: true
        command: ["xdg-user-dir", "DOCUMENTS"]
        stdout: StdioCollector {
            // With no documents folder set, xdg-user-dir answers $HOME itself.
            onStreamFinished: {
                const d = text.trim();
                if (d.startsWith("/") && d !== Quickshell.env("HOME")) root.outDir = d + "/Assistant";
            }
        }
    }

    // A file whose name says nothing (a script with no suffix) is "other"
    // until file(1) has read it. One run for all of them; the daemon makes
    // its own call on the content when the question is sent.
    function refine() {
        const unknown = root.staged.filter(f => f.kind === "other").map(f => f.path);
        if (!unknown.length) return;
        sniff.paths = unknown;
        sniff.running = false;            // a running Process ignores running = true
        sniff.running = true;
    }

    Process {
        id: sniff
        property var paths: []
        command: ["file", "-b", "--mime-type", "--"].concat(paths)
        stdout: StdioCollector {
            onStreamFinished: {
                const mimes = text.trim().split("\n");
                root.staged = root.staged.map(f => {
                    const i = sniff.paths.indexOf(f.path);
                    return i < 0 || f.kind !== "other" ? f
                         : Object.assign({}, f, { kind: Files.fromMime(mimes[i] ?? "") });
                });
            }
        }
    }
    function unstage(i) {
        const s = root.staged.slice();
        s.splice(i, 1);
        root.staged = s;
    }

    function send(cmd) {
        if (!link.item) return;
        link.item.write(JSON.stringify(cmd) + "\n");
        link.item.flush();
    }

    // The chips stay until the daemon's user event takes them: a refused
    // file (unreadable, too big, a model without vision) comes back as an
    // error, and the chips must still be there to fix it. chatting keeps the
    // chat layout meanwhile, so the card does not shrink while a PDF is read.
    function ask(text) {
        if (!root.connected || root.blocked || root.opRunning
            || (text.trim() === "" && !root.staged.length)) return false;
        root.notice = "";
        root.chatting = true;
        root.send({ type: "ask", text: text, files: root.staged.map(f => f.path) });
        return true;
    }

    function showHistory() {
        root.pickerOpen = false;
        root.historyOpen = true;
        root.send({ type: "list" });
    }

    function row(t, live) {
        return { user: t.user ?? "", reply: t.reply ?? "", think: t.think ?? "",
                 tools: (t.tools ?? []).join(","), error: "", live: live,
                 // JSON for the same reason tools is a string.
                 files: JSON.stringify(t.files ?? []),
                 stopped: false, expanded: false };
    }

    function load(id, list, pending) {
        root.bufReply = root.bufThink = "";
        turns.clear();
        for (const t of list) turns.append(root.row(t, false));
        if (pending) turns.append(root.row(pending, true));
        root.convId = id;
        root.notice = "";
    }

    function last() { return turns.count ? turns.get(turns.count - 1) : null; }

    function flush() {
        const t = root.last();
        if (!t || !t.live) { root.bufReply = root.bufThink = ""; return; }
        if (root.bufThink) turns.setProperty(turns.count - 1, "think", t.think + root.bufThink);
        if (root.bufReply) turns.setProperty(turns.count - 1, "reply", t.reply + root.bufReply);
        root.bufReply = root.bufThink = "";
    }

    function handle(line) {
        let e;
        try { e = JSON.parse(line); } catch (err) { return; }
        const i = turns.count - 1;
        switch (e.type) {
        case "hello":
            root.state = e.state;
            root.runningTool = e.state === "tool" ? e.tool : "";
            root.model = e.model ?? "";
            root.ctxUsed = e.ctx_used;
            root.ctxMax = e.ctx_max;
            root.load(e.id, e.turns, e.pending);
            // A restart or reload counts as active: the conversation it
            // reconnects to is not stale just because this process is new.
            if (e.pending || e.turns.length) root.lastActive = Date.now();
            break;
        case "conversation":
            root.load(e.id, e.turns, null);
            // Opened from History on purpose: it counts as active now.
            if (e.turns.length) root.lastActive = Date.now();
            // Emptied (New, or the current one deleted) with nothing staged:
            // back to the entry line.
            else if (!root.staged.length) root.chatting = false;
            break;
        case "user":
            turns.append(root.row({ user: e.text, files: e.files }, true));
            root.staged = [];
            root.lastActive = Date.now();
            break;
        case "think": root.bufThink += e.delta; break;
        case "token": root.bufReply += e.delta; break;
        case "tool":
            root.flush();
            if (!e.done && i >= 0 && turns.get(i).live) {
                const t = turns.get(i).tools;
                turns.setProperty(i, "tools", t ? t + "," + e.name : e.name);
            }
            break;
        case "done":
            root.flush();
            if (i >= 0 && turns.get(i).live) {
                turns.setProperty(i, "live", false);
                turns.setProperty(i, "stopped", e.stopped === true);
            }
            if (!e.stopped) root.convId = e.id;
            root.lastActive = Date.now();
            break;
        case "progress": if (root.opDaemon) root.opChars = e.chars; break;
        case "written":
            if (root.opDaemon && root.opRunning) { root.opRunning = false; root.opOut = [e.path]; }
            break;
        case "error":
            // A write's outcome. An older daemon answers it with a plain
            // error and no turn; while nothing else runs, that is the write's.
            if (root.opDaemon && root.opRunning && (e.turn || root.state === "idle")) {
                root.opRunning = false;
                root.opError = e.message;
                break;
            }
            // Only an error marked turn ended the reply. A command error,
            // perhaps another client's, leaves a streaming reply alone.
            if (e.turn && i >= 0 && turns.get(i).live) {
                root.flush();
                turns.setProperty(i, "error", e.message);
                turns.setProperty(i, "live", false);
            } else {
                root.notice = e.message;
            }
            break;
        case "state":
            root.state = e.state;
            root.runningTool = e.state === "tool" ? e.tool : "";
            break;
        // ctx carries the model since the router can swap it after hello; an
        // older daemon leaves it out, and the hello's name stands.
        case "ctx": root.ctxUsed = e.used; root.ctxMax = e.max; if (e.model) root.model = e.model; break;
        case "conversations": root.convs = e.items; break;
        case "results": root.results = e.items; break;
        }
    }

    Timer {
        interval: 50
        repeat: true
        running: root.bufReply !== "" || root.bufThink !== ""
        onTriggered: root.flush()
    }

    // The daemon may start after this shell, or restart: keep trying with a
    // fresh Socket each time. Quickshell 0.3.1 keeps the QLocalSocket of a
    // failed connect, so setting `connected` again on the same Socket never
    // retries. See AGENTS.md.
    LazyLoader {
        id: link
        active: true
        Socket {
            path: root.socketPath
            connected: true
            parser: SplitParser { onRead: line => root.handle(line) }
        }
    }

    Timer {
        interval: 2000
        repeat: true
        running: !root.connected
        onTriggered: { link.active = false; link.active = true; }
    }

    LazyLoader {
        active: root.open

        PanelWindow {
            screen: root.screenObj
            anchors { top: true; left: true; right: true; bottom: true }
            color: Qt.alpha(Theme.crust, 0.35)
            exclusionMode: ExclusionMode.Ignore
            WlrLayershell.layer: WlrLayer.Overlay
            WlrLayershell.namespace: "quickshell-assistant"
            WlrLayershell.keyboardFocus: WlrKeyboardFocus.Exclusive

            MouseArea { anchors.fill: parent; onClicked: root.close() }

            Card {
                anchors.centerIn: parent
                width: Math.min(760, parent.width - 48)
                fullHeight: Math.round(parent.height * 0.7)
                canvas: root
                turnModel: turns
            }
        }
    }
}