pragma Singleton

// The allow-listed machine boundary for Panama Settings. Visual pages call
// these methods; no UI text is ever interpolated into a shell command.

import Quickshell
import Quickshell.Io
import QtQuick
import qs.config

Singleton {
    id: root

    property string monitorName: ""
    property string monitorDescription: ""
    property int monitorWidth: 0
    property int monitorHeight: 0
    property real monitorRefreshRate: 0
    property real monitorScale: 1
    property string monitorFormat: ""
    property string colorPreset: ""
    property bool monitorVrrActive: false

    property bool nextcloudActive: false
    property bool rustdeskActive: false
    property bool kdeconnectActive: false
    property bool hyprpaperActive: false
    property bool hypridleActive: false
    property bool vicinaeActive: false
    property bool bluebubblesDetected: false

    property string hyprlandVersion: ""
    property string quickshellVersion: "0.3.0"
    property string lastError: ""

    // Explicit seams keep reset sequencing testable without changing the live
    // keymap, wallpaper, or display from an isolated contract harness.
    property var displayBusy: function() { return Displays.busy || Displays.awaitingConfirmation; }
    property var readDisplays: function() { return DesktopPreferences.get("displays"); }
    property var protectDisplays: function(value) { return DesktopPreferences.set("displays", value); }
    property var setDisplayBlocked: function(blocked) { Displays.externalChangeBlocked = blocked; }
    property var reloadKeybinds: function() { Keybinds.applyReload(); }
    property var keybindsReloading: function() { return Keybinds.reloading; }
    property var applyWallpaper: function(path) { Wallpaper.set(path); }

    readonly property bool busy: monitorQuery.running || serviceQuery.running || versionQuery.running
        || configWrite.running || configVerify.running || bluebubblesQuery.running

    readonly property bool bluebubblesAvailable: root.bluebubblesDetected

    readonly property bool autoHdr: DesktopPreferences.get("autoHdr")
    readonly property int vrrPolicy: DesktopPreferences.get("vrrPolicy")
    readonly property int directScanoutPolicy: DesktopPreferences.get("directScanoutPolicy")

    // ── The Hyprland write boundary ─────────────────────────────────────────
    // Every option Panama may write, with the hl.config path used to set it and
    // the getoption path used to read it back. The UI never names an option or
    // supplies a raw value: it calls a setter, which resolves the option here
    // and range-checks the value against `allowed`. Nothing user-supplied is
    // ever interpolated into the payload.
    //
    // `hyprctl keyword` is deliberately NOT used. On a Lua-configured Hyprland
    // it refuses the write, prints "keyword can't work with non-legacy parsers"
    // to stdout, and still exits 0 -- so code branching on the exit status
    // believes it succeeded. `hyprctl eval` has the same hazard: it exits 0 on
    // syntax and runtime errors, reporting them as an "error:" line instead.
    //
    // Success therefore means exactly one thing here: the value was read back
    // from the compositor and matched what was requested.
    //
    // The set of writable options is not restated here: it is every schema
    // entry carrying a `hypr` block. Adding a live-adjustable Hyprland setting
    // is a schema entry plus a prefs.get() call in the Lua, and needs no new
    // code in this file.

    Process {
        id: monitorQuery
        command: ["hyprctl", "-j", "monitors"]
        stdout: StdioCollector {
            onStreamFinished: root.parseMonitors(this.text)
        }
        onExited: (exitCode, exitStatus) => {
            if (exitCode !== 0)
                root.lastError = "Could not read the active display.";
        }
    }

    Process {
        id: serviceQuery
        command: [
            "bash", "-lc",
            "printf '{\"nextcloud\":%s,\"rustdesk\":%s,\"kdeconnect\":%s,\"hyprpaper\":%s,\"hypridle\":%s,\"vicinae\":%s}\\n' "
                + "$(pgrep -x nextcloud >/dev/null && printf true || printf false) "
                + "$(systemctl is-active --quiet rustdesk.service && printf true || printf false) "
                + "$(pgrep -x kdeconnectd >/dev/null && printf true || printf false) "
                + "$(systemctl --user is-active --quiet hyprpaper.service && printf true || printf false) "
                + "$(systemctl --user is-active --quiet hypridle.service && printf true || printf false) "
                + "$(systemctl --user is-active --quiet vicinae.service && printf true || printf false)"
        ]
        stdout: StdioCollector {
            onStreamFinished: root.parseServices(this.text)
        }
    }

    Process {
        id: versionQuery
        command: ["Hyprland", "--version"]
        stdout: StdioCollector {
            onStreamFinished: {
                const match = this.text.match(/Hyprland\s+([0-9.]+)/);
                root.hyprlandVersion = match ? match[1] : this.text.trim().split("\n")[0];
            }
        }
    }

    // Applies a validated batch of options in one `hl.config{}` call, then hands
    // off to configVerify. Never commits anything on its own: an "ok" here only
    // means Hyprland parsed the payload.
    Process {
        id: configWrite

        // id -> integer value, already validated by applyOptions().
        property var pending: ({})

        stdout: StdioCollector {
            onStreamFinished: {
                if (this.text.indexOf("error:") >= 0) {
                    root.reportWriteFailure(configWrite.pending, this.text);
                    return;
                }
                root.verifyPending();
            }
        }
    }

    Process {
        id: bluebubblesQuery
        command: ["flatpak", "info", "app.bluebubbles.BlueBubbles"]
        onExited: (exitCode, exitStatus) => root.bluebubblesDetected = exitCode === 0
    }

    // Reads the written options back out of the compositor. This is the only
    // thing that decides whether a write succeeded.
    Process {
        id: configVerify

        stdout: StdioCollector {
            onStreamFinished: root.commitVerified(configWrite.pending, this.text)
        }
    }

    Timer {
        // Preferences load asynchronously from disk. Applying after one quiet
        // second avoids racing their restore and runs only once per shell start.
        interval: 1000
        running: true
        onTriggered: root.applyPersistedDisplayPolicy()
    }

    Component.onCompleted: root.refresh()

    function refresh(): void {
        root.lastError = "";
        if (!monitorQuery.running)
            monitorQuery.running = true;
        if (!serviceQuery.running)
            serviceQuery.running = true;
        if (!versionQuery.running && !root.hyprlandVersion)
            versionQuery.running = true;
        if (!bluebubblesQuery.running)
            bluebubblesQuery.running = true;
    }

    function parseMonitors(text: string): void {
        try {
            const monitors = JSON.parse(text);
            const monitor = monitors.find(item => item.focused) ?? monitors[0];
            if (!monitor)
                throw new Error("No active monitor");
            root.monitorName = monitor.name ?? "";
            root.monitorDescription = monitor.description ?? monitor.model ?? "Display";
            root.monitorWidth = monitor.width ?? 0;
            root.monitorHeight = monitor.height ?? 0;
            root.monitorRefreshRate = monitor.refreshRate ?? 0;
            root.monitorScale = monitor.scale ?? 1;
            root.monitorFormat = monitor.currentFormat ?? "";
            root.colorPreset = monitor.colorManagementPreset ?? "";
            root.monitorVrrActive = monitor.vrr ?? false;
        } catch (error) {
            root.lastError = "The display response could not be read.";
        }
    }

    function parseServices(text: string): void {
        try {
            const state = JSON.parse(text);
            root.nextcloudActive = state.nextcloud === true;
            root.rustdeskActive = state.rustdesk === true;
            root.kdeconnectActive = state.kdeconnect === true;
            root.hyprpaperActive = state.hyprpaper === true;
            root.hypridleActive = state.hypridle === true;
            root.vicinaeActive = state.vicinae === true;
        } catch (error) {
            root.lastError = "Startup-service status could not be read.";
        }
    }

    // ── Applying options ────────────────────────────────────────────────────
    // `values` maps schema keys to values, e.g. { vrrPolicy: 3, gapsOut: 12 }.
    // The whole batch is validated before anything is sent, so one bad value
    // rejects the batch rather than half-applying it.
    function applyOptions(values: var): bool {
        const requested = {};
        for (const key in values) {
            const entry = PreferenceSchema.spec(key);
            if (!entry || !entry.hypr) {
                root.lastError = "That setting is not applied by the compositor.";
                return false;
            }
            const coerced = PreferenceSchema.coerce(key, values[key]);
            if (coerced === undefined) {
                root.lastError = `Unsupported value for ${entry.label}.`;
                return false;
            }
            requested[key] = coerced;
        }
        if (Object.keys(requested).length === 0)
            return false;

        // A write in flight is queued rather than refused. Options are applied
        // and verified one batch at a time, but the callers are a settings UI
        // and a startup replay of every compositor-backed preference -- they
        // overlap routinely, and dropping a change on the floor would leave the
        // stored value and the compositor disagreeing. Later values for the
        // same key win.
        if (configWrite.running || configVerify.running) {
            root.queued = Object.assign({}, root.queued, requested);
            return true;
        }

        root.startWrite(requested);
        return true;
    }

    // Merged batches waiting for the current write to finish.
    property var queued: ({})

    function startWrite(requested: var): void {
        configWrite.pending = requested;
        configWrite.exec(["hyprctl", "eval", root.buildConfigPayload(requested)]);
    }

    // Called when a write settles, however it settled. A failed batch must not
    // strand whatever queued up behind it.
    function drainQueue(): void {
        const next = root.queued;
        if (Object.keys(next).length === 0)
            return;
        root.queued = ({});
        root.startWrite(next);
    }

    // The value as Hyprland stores it. Several options are a toggle in the UI
    // but an integer in the compositor (cm_auto_hdr, follow_mouse); `readAs`
    // decides, and config/dot/hypr/prefs.lua does the same conversion via
    // prefs.getInt so both sides agree.
    function hyprValue(entry: var, value: var): var {
        if (typeof value === "boolean" && entry.hypr.readAs !== "bool")
            return value ? 1 : 0;
        return value;
    }

    // Serialises validated values into a nested hl.config{} call. Table paths
    // come from the schema and values have already passed coerce(), including
    // the pattern check on constrained strings, so nothing caller-supplied
    // reaches the payload unchecked.
    function buildConfigPayload(requested: var): string {
        const tree = {};
        for (const key in requested) {
            const entry = PreferenceSchema.spec(key);
            const path = entry.hypr.path;
            let node = tree;
            for (let i = 0; i < path.length - 1; i++)
                node = node[path[i]] = node[path[i]] ?? {};
            node[path[path.length - 1]] = root.serialiseValue(root.hyprValue(entry, requested[key]));
        }
        return `hl.config(${root.serialiseTable(tree)})`;
    }

    function serialiseValue(value: var): string {
        if (typeof value === "boolean")
            return value ? "true" : "false";
        if (typeof value === "number")
            return String(value);
        // Strings only reach here after the schema's pattern check; quoting is
        // belt-and-braces rather than the primary defence.
        return `"${String(value).replace(/["\\]/g, "")}"`;
    }

    function serialiseTable(node: var): string {
        const parts = [];
        for (const name in node) {
            const child = node[name];
            parts.push(`${name} = ${typeof child === "string" ? child : root.serialiseTable(child)}`);
        }
        return `{ ${parts.join(", ")} }`;
    }

    function verifyPending(): void {
        const options = Object.keys(configWrite.pending)
            .map(key => `getoption ${PreferenceSchema.spec(key).hypr.option}`)
            .join(" ; ");
        configVerify.exec(["hyprctl", "-j", "--batch", options]);
    }

    // The compositor's answer is authoritative. Preferences are only updated for
    // options that actually read back with the requested value.
    function commitVerified(requested: var, text: string): void {
        // Each getoption answers with its own flat JSON object, and the field
        // carrying the value depends on the option's type -- int, bool, float,
        // str, or css for the gap box.
        const observed = {};
        for (const block of text.match(/\{[^{}]*\}/g) ?? []) {
            try {
                const parsed = JSON.parse(block);
                if (parsed.option !== undefined)
                    observed[parsed.option] = parsed;
            } catch (error) {
                // A partial line is treated as "not observed", which fails the
                // comparison below rather than being mistaken for success.
            }
        }

        const rejected = [];
        for (const key in requested) {
            const entry = PreferenceSchema.spec(key);
            if (!root.matchesObserved(entry, requested[key], observed[entry.hypr.option])) {
                rejected.push(entry.label);
                continue;
            }
            DesktopPreferences.set(key, requested[key]);
        }

        root.lastError = rejected.length === 0 ? "" : `Hyprland did not apply ${rejected.join(" or ")}.`;
        root.drainQueue();
    }

    function matchesObserved(entry: var, value: var, answer: var): bool {
        if (!answer)
            return false;
        const expected = root.hyprValue(entry, value);
        switch (entry.hypr.readAs) {
        case "bool":
            return answer.bool === expected;
        case "int":
            return answer.int === expected;
        case "float":
            // getoption prints six decimal places; compare within that.
            return Math.abs(answer.float - expected) < 1e-5;
        case "str":
            return answer.str === expected;
        case "css":
            // Gaps read back as a box, e.g. "10 10 10 10".
            return Number(String(answer.css).trim().split(/\s+/)[0]) === expected;
        }
        return false;
    }

    function reportWriteFailure(requested: var, text: string): void {
        const labels = Object.keys(requested).map(key => PreferenceSchema.spec(key).label);
        root.lastError = `Hyprland rejected ${labels.join(" and ")}.`;
        root.drainQueue();
    }

    // The one entry point the settings UI uses to change any preference.
    //
    // A compositor-backed setting must be applied and verified before it is
    // stored, so that preferences never claim a value Hyprland refused.
    // Everything else is a direct write. Rows bind a schema key and call this;
    // they never need to know which kind they are holding.
    function commitPreference(key: string, value: var): bool {
        const entry = PreferenceSchema.spec(key);
        if (!entry) {
            root.lastError = "That setting is not part of Panama.";
            return false;
        }
        if (entry.hypr) {
            const batch = {};
            batch[key] = value;
            return root.applyOptions(batch);
        }
        return DesktopPreferences.set(key, value);
    }

    // Restores shipped defaults across every store Panama owns, not just the
    // schema. Panama keeps user state in more than one file -- the schema store,
    // the focus session, and the Home accessory arrangement -- and a reset that
    // silently skipped one would be worse than no reset at all.
    //
    // Compositor-backed values are re-applied afterwards, since resetting the
    // stored value does not by itself tell Hyprland anything.
    function restoreDefaults(): bool {
        if (root.displayBusy()) {
            root.lastError = "Finish the current display change before restoring defaults.";
            return false;
        }

        const currentDisplays = root.readDisplays();
        const protectedDisplays = JSON.parse(JSON.stringify(
            currentDisplays && typeof currentDisplays === "object" ? currentDisplays : {}));
        root.setDisplayBlocked(true);
        DesktopPreferences.resetDesktopDefaults();
        if (!root.protectDisplays(protectedDisplays)) {
            root.setDisplayBlocked(false);
            root.lastError = "The current display setting could not be protected during reset.";
            return false;
        }

        // Home accessories keep their own store (panama-home.json), so a reset
        // that only cleared the schema store would silently leave a customised
        // favourites list behind while claiming to restore Panama's defaults.
        //
        // HomePreferences owns the write-through boundary so the state file is
        // rewritten before this reset can be considered complete.
        HomePreferences.resetHomeDefaults();

        resettleTimer.restart();
        return true;
    }

    Timer {
        id: resettleTimer
        interval: 60
        onTriggered: {
            root.applyPersistedDisplayPolicy();
            root.reloadKeybinds();
            root.applyWallpaper(String(DesktopPreferences.get("wallpaperPath") ?? ""));
            resetRelease.attempts = 0;
            resetRelease.restart();
        }
    }

    Timer {
        id: resetRelease
        property int attempts: 0
        interval: 100
        repeat: true
        onTriggered: {
            attempts++;
            if ((!root.keybindsReloading() && !root.busy) || attempts >= 50) {
                stop();
                root.setDisplayBlocked(false);
            }
        }
    }

    function setAutoHdr(enabled: bool): void {
        root.applyOptions({ autoHdr: enabled });
    }

    function setVrrPolicy(policy: int): void {
        root.applyOptions({ vrrPolicy: policy });
    }

    function setDirectScanoutPolicy(policy: int): void {
        root.applyOptions({ directScanoutPolicy: policy });
    }

    // Replays every compositor-owned preference in one batch at shell start, so
    // a value the user changed in Settings survives a reboot even though the
    // Lua config only reads the file once, at launch.
    function applyPersistedDisplayPolicy(): void {
        const values = {};
        for (const entry of PreferenceSchema.hyprEntries())
            values[entry.key] = DesktopPreferences.get(entry.key);
        root.applyOptions(values);
    }

    function isGnomePanelAllowed(panel: string): bool {
        // Verified against `gnome-control-center --list` on this system. A name
        // that panel list does not contain opens nothing and reports an error,
        // so guessing one here would be a silently dead button.
        return [
            "applications", "background", "bluetooth", "color", "display",
            "keyboard", "mouse", "multitasking", "network", "notifications",
            "online-accounts", "power", "printers", "privacy", "search",
            "sharing", "sound", "system", "universal-access", "wacom",
            "wellbeing", "wifi", "wwan"
        ].indexOf(panel) >= 0;
    }

    function openGnomePanel(panel: string): bool {
        if (!root.isGnomePanelAllowed(panel)) {
            root.lastError = "That GNOME Settings panel is not available.";
            return false;
        }
        Quickshell.execDetached({
            command: ["gnome-control-center", panel],
            environment: { "XDG_CURRENT_DESKTOP": "GNOME" }
        });
        return true;
    }

    function openApplication(id: string): bool {
        const commands = {
            "nextcloud": ["nextcloud"],
            "rustdesk": ["rustdesk"],
            "kdeconnect": ["kdeconnect-app"],
            "mission-center": ["flatpak", "run", "io.missioncenter.MissionCenter"],
            "bluebubbles": ["flatpak", "run", "app.bluebubbles.BlueBubbles"]
        };
        const command = commands[id];
        if (!command) {
            root.lastError = "That application is not managed by Panama Settings.";
            return false;
        }
        Quickshell.execDetached(command);
        return true;
    }
}