function shellQuote(value) {
    return "'" + String(value).replace(/'/g, "'\\''") + "'";
}

function serviceCommands(action) {
    var groups = action.scopes || [{ scope: "system", units: action.units || [] }, { scope: "user", units: action.units || [] }];
    var commands = [];
    groups.forEach(function (group) {
        if (!group.units.length) return;
        var prefix = ["systemctl"].concat(group.scope === "user" ? ["--user"] : []);
        commands.push(prefix.concat(["--no-pager", "--full", "status", "--"], group.units));
    });
    return commands;
}

function eventCommand(action) {
    if (!/^[0-9a-f]{32}$/.test(action.bootId || "") || !/^[\x21-\x7e]{1,512}$/.test(action.cursor || "") || !isFinite(Date.parse(action.timestamp))) return null;
    return ["journalctl", "--boot=" + action.bootId, "--cursor=" + action.cursor, "--lines=+1", "--no-pager"];
}

function eventContextCommand(action) {
    var time = Date.parse(action.timestamp);
    if (!/^[0-9a-f]{32}$/.test(action.bootId || "") || !isFinite(time)) return null;
    // PIDs can be reused. Pin the boot and a narrow time interval instead.
    return ["journalctl", "--boot=" + action.bootId, "--since=" + new Date(time - 60000).toISOString(),
        "--until=" + new Date(time + 60000).toISOString(), "--lines=100", "--no-pager"];
}

function terminalCommands(commands) {
    return ["wezterm", "start", "--", "sh", "-c", commands.map(function (argv) {
        return argv.map(shellQuote).join(" ");
    }).join("; ") + '; exec "$SHELL"'];
}

function actionPlan(action) {
    var a = action || {};
    var kind = String(a.kind || "");
    if (kind === "btm") return { ok: true, kind: kind, argv: ["wezterm", "start", "--", "btm"] };
    if (kind === "systemctl-status") return { ok: true, kind: kind, argv: terminalCommands(serviceCommands(a)) };
    if (kind === "journal-event") {
        var command = eventCommand(a);
        if (command) return { ok: true, kind: kind, argv: terminalCommands([command, eventContextCommand(a)]) };
    }
    if (kind === "open-mount") return { ok: true, kind: kind, argv: ["wezterm", "start", "--cwd", String(a.target || "/")] };
    if (kind === "update") return { ok: true, kind: kind, argv: ["wezterm", "start", "--", "sh", "-c", 'sudo pacman -Syu; exec "$SHELL"'] };
    return { ok: false, reason: "unknown-action", kind: kind };
}

function issueAction(issues, id) {
    var issue = (issues || []).filter(function (entry) { return entry.id === String(id); })[0];
    if (!issue || !issue.action) return { ok: false, reason: "no-action", id: String(id) };
    var plan = actionPlan(issue.action);
    if (!plan.ok) return plan;
    return { ok: true, id: String(id), kind: plan.kind, argv: plan.argv };
}

function agentAllowed(issue) {
    return !!issue && issue.id !== "updates" && issue.id !== "battery-health";
}

function agentAction(issues, id, context, template) {
    var issue = (issues || []).filter(function (entry) { return entry.id === String(id); })[0];
    if (!issue) return { ok: false, reason: "issue-gone", id: String(id) };
    if (!agentAllowed(issue)) return { ok: false, reason: "agent-not-applicable", id: String(id) };
    var ctx = context || {};
    if (!ctx.home || String(ctx.home)[0] !== "/") return { ok: false, reason: "home-unavailable", id: String(id) };
    var stateHome = ctx.stateHome && String(ctx.stateHome)[0] === "/" ? String(ctx.stateHome) : String(ctx.home).replace(/\/+$/, "") + "/.local/state";
    var workingDirectory = stateHome.replace(/\/+$/, "") + "/nuguland/repairs";
    var parts = String(template || "").split("{{context}}");
    if (parts.length !== 2) return { ok: false, reason: "prompt-invalid", id: String(id) };
    var snapshot = {
        observedAt: ctx.observedAt,
        machine: ctx.identity || {},
        issue: {
            id: issue.id,
            type: issue.context ? issue.context.source : String(issue.id).split(":")[0],
            label: issue.label,
            detail: issue.detail,
            severity: issue.severity,
            historical: !!issue.context,
            measurements: issue.measurements || null,
            context: issue.context || null,
            occurrences: issue.context ? (issue.events || [issue.context]).length : null,
            events: issue.events || (issue.context ? [issue.context] : [])
        },
        serviceScopes: issue.action && issue.action.scopes || []
    };
    // One literal substitution: injected metadata is never re-expanded.
    var prompt = parts[0] + JSON.stringify(snapshot, null, 2) + parts[1];
    return { ok: true, id: String(id), kind: "agent", argv: ["wezterm", "start", "--cwd", workingDirectory, "--", "pi", "--name", "arrrgh: " + issue.label, "--", prompt] };
}

function issueHeading(issue) {
    var metadata = issue.context && issue.context.metadata;
    if (metadata) return metadata.comm || metadata.executable || metadata.target || issue.label;
    if (issue.action && issue.action.kind === "systemctl-status") return issue.action.units.join(", ");
    return issue.label;
}

function issueDescription(issue) {
    var metadata = issue.context && issue.context.metadata;
    if (metadata) {
        var label = issue.events ? issue.events.length + (issue.events.length === 1 ? " crash" : " crashes") : issue.label;
        var signal = (metadata.signal || "").toLowerCase();
        if (issue.events && issue.events.length > 1 && signal) signal = "latest " + signal;
        return [label, signal, metadata.pid ? "pid " + metadata.pid : ""].filter(Boolean).join(" · ");
    }
    if (issue.action && issue.action.kind === "systemctl-status") return issue.label + " · " + (issue.action.scopes || []).filter(function (group) { return group.units.length; }).map(function (group) { return group.scope; }).join(" / ");
    return issue.detail;
}

function eventTime(timestamp, now) {
    var event = new Date(timestamp);
    var current = new Date(now);
    if (!isFinite(event.getTime()) || !isFinite(current.getTime())) return "";
    var minutes = Math.max(0, Math.floor((current - event) / 60000));
    var ago = minutes < 1 ? "just now" : minutes < 60 ? minutes + " min ago" : Math.floor(minutes / 60) + " h ago";
    var yesterday = new Date(current.getFullYear(), current.getMonth(), current.getDate() - 1);
    var day = event.toDateString() === current.toDateString() ? "today" : event.toDateString() === yesterday.toDateString() ? "yesterday" : event.getDate() + "/" + (event.getMonth() + 1);
    function pad(n) { return n < 10 ? "0" + n : String(n); }
    return ago + " · " + day + ", " + pad(event.getHours()) + ":" + pad(event.getMinutes());
}

if (typeof module !== 'undefined' && module.exports) {
    module.exports = { actionPlan: actionPlan, issueAction: issueAction, agentAction: agentAction, agentAllowed: agentAllowed,
        issueHeading: issueHeading, issueDescription: issueDescription, eventTime: eventTime };
}