import type { StorageNamespace } from "@dispatch/kernel";
import type {
  EnqueueInput,
  EnqueueResult,
  SessionOrchestrator,
  StartTurnResult,
  TurnEventListener,
} from "@dispatch/session-orchestrator";
import { describe, expect, it } from "vitest";
import { createHeartbeatService } from "./heartbeat.js";

function createMemoryStorage(): StorageNamespace {
  const data = new Map<string, string>();
  return {
    get: async (key) => data.get(key) ?? null,
    set: async (key, value) => {
      data.set(key, value);
    },
    delete: async (key) => {
      data.delete(key);
    },
    has: async (key) => data.has(key),
    keys: async (prefix) => {
      const all = [...data.keys()];
      if (prefix === undefined) return all;
      return all.filter((k) => k.startsWith(prefix));
    },
  };
}

/** A controllable fake clock with an `advance` to move virtual time. */
function createFakeTimers() {
  let now = 0;
  let nextId = 1;
  const timers = new Map<number, { readonly fn: () => void; readonly firesAt: number }>();
  return {
    timers: {
      now: () => now,
      setTimeout: (fn: () => void, ms: number) => {
        const id = nextId++;
        timers.set(id, { fn, firesAt: now + ms });
        return id as unknown as ReturnType<typeof setTimeout>;
      },
      clearTimeout: (handle: ReturnType<typeof setTimeout> | undefined) => {
        if (handle !== undefined) timers.delete(handle as unknown as number);
      },
    },
    advance(ms: number): void {
      now += ms;
      const due = [...timers.entries()]
        .filter(([, t]) => t.firesAt <= now)
        .sort((a, b) => a[0] - b[0]);
      for (const [id, t] of due) {
        timers.delete(id);
        t.fn();
      }
    },
  };
}

interface PendingTurn {
  readonly conversationId: string;
  readonly text: string;
  readonly systemPrompt?: string;
  readonly modelName?: string;
  readonly reasoningEffort?: unknown;
  readonly workspaceId?: string;
  readonly cwd?: string;
  resolve: () => void;
}

/**
 * A fake orchestrator that records handleMessage calls and lets the test
 * control when each turn seals. This is the injected edge — the service depends
 * on the SessionOrchestrator interface, not its implementation.
 */
function createFakeOrchestrator(): SessionOrchestrator & {
  readonly pending: readonly PendingTurn[];
  readonly stopped: readonly string[];
} {
  const pending: PendingTurn[] = [];
  const stopped: string[] = [];
  const turns = new Map<string, { resolve: () => void; reject: (e: unknown) => void }>();

  const fake: SessionOrchestrator = {
    startTurn(): StartTurnResult {
      return { started: false, reason: "already-active" };
    },
    enqueue(_input: EnqueueInput): EnqueueResult {
      return { startedTurn: false, queue: [] };
    },
    subscribe(_conversationId: string, _listener: TurnEventListener): () => void {
      return () => {};
    },
    isActive(_conversationId: string): boolean {
      return false;
    },
    closeConversation(_conversationId: string): { abortedTurn: boolean } {
      return { abortedTurn: false };
    },
    stopTurn(conversationId: string): { abortedTurn: boolean } {
      stopped.push(conversationId);
      const t = turns.get(conversationId);
      if (t !== undefined) {
        turns.delete(conversationId);
        t.resolve();
      }
      return { abortedTurn: true };
    },
    handleMessage(input): Promise<void> {
      return new Promise<void>((resolve, reject) => {
        const entry: PendingTurn = {
          conversationId: input.conversationId,
          text: input.text,
          ...(input.systemPrompt !== undefined ? { systemPrompt: input.systemPrompt } : {}),
          ...(input.modelName !== undefined ? { modelName: input.modelName } : {}),
          ...(input.reasoningEffort !== undefined
            ? { reasoningEffort: input.reasoningEffort }
            : {}),
          ...(input.workspaceId !== undefined ? { workspaceId: input.workspaceId } : {}),
          ...(input.cwd !== undefined ? { cwd: input.cwd } : {}),
          resolve,
        };
        pending.push(entry);
        turns.set(input.conversationId, { resolve, reject });
      });
    },
  };
  return Object.assign(fake, {
    get pending(): readonly PendingTurn[] {
      return pending;
    },
    get stopped(): readonly string[] {
      return stopped;
    },
  });
}

// Drain microtasks so async .finally handlers (run completion) run. `fire` has
// nested awaits (configStore.get → storage.get, runStore.create → storage.set)
// before it reaches handleMessage, so a single queueMicrotask isn't enough —
// setTimeout(0) schedules a macrotask, letting ALL pending microtasks drain.
const flush = async (): Promise<void> => {
  await new Promise((r) => setTimeout(r, 0));
};

function createService(opts: {
  readonly orch: ReturnType<typeof createFakeOrchestrator>;
  readonly storage?: StorageNamespace;
  readonly resolvePrompt?: (
    template: string,
    ctx: {
      readonly workspaceId: string;
      readonly conversationId: string;
      readonly model: string;
    },
  ) => Promise<string>;
  readonly getGlobalSystemPrompt?: () => Promise<string>;
  readonly getWorkspaceCwd?: (workspaceId: string) => Promise<string | null>;
}) {
  const fake = createFakeTimers();
  let id = 0;
  const storage = opts.storage ?? createMemoryStorage();
  const svc = createHeartbeatService({
    storage,
    orchestrator: opts.orch,
    timers: fake.timers,
    generateId: () => `id-${++id}`,
    ...(opts.resolvePrompt !== undefined ? { resolvePrompt: opts.resolvePrompt } : {}),
    ...(opts.getGlobalSystemPrompt !== undefined
      ? { getGlobalSystemPrompt: opts.getGlobalSystemPrompt }
      : {}),
    ...(opts.getWorkspaceCwd !== undefined ? { getWorkspaceCwd: opts.getWorkspaceCwd } : {}),
  });
  return { svc, advance: fake.advance, storage };
}

describe("createHeartbeatService", () => {
  it("returns the default config for an unknown workspace", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    const cfg = await svc.getConfig("ws-1");
    expect(cfg.enabled).toBe(false);
    expect(cfg.intervalMinutes).toBe(30);
  });

  it("arming an enabled config does not fire immediately (waits for the interval)", () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    void svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go" });
    // Just arming → no turn yet.
    expect(orch.pending).toHaveLength(0);
    // Advancing just shy of the interval still no fire.
    advance(59_999);
    expect(orch.pending).toHaveLength(0);
  });

  it("fire sends the task prompt with the explicit system prompt + model + effort, and marks completed on seal", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", {
      enabled: true,
      systemPrompt: "you are a monitor",
      taskPrompt: "check stuck chats",
      model: "opencode/gpt-4o",
      reasoningEffort: "high",
      intervalMinutes: 1,
    });

    advance(60_000); // 1-minute interval → fire
    await flush(); // let the async fire() reach handleMessage
    expect(orch.pending).toHaveLength(1);
    const turn = orch.pending[0]!;
    expect(turn.text).toBe("check stuck chats");
    expect(turn.systemPrompt).toBe("you are a monitor");
    expect(turn.modelName).toBe("opencode/gpt-4o");
    expect(turn.reasoningEffort).toBe("high");
    // Spawned conversations go to the DEDICATED heartbeat workspace (not
    // the configured workspace), while the run stays tracked under ws-1.
    expect(turn.workspaceId).toBe("heartbeat");

    expect((await svc.listRuns("ws-1"))[0]?.status).toBe("running");

    turn.resolve();
    await flush();
    expect((await svc.listRuns("ws-1"))[0]?.status).toBe("completed");
  });

  it("heartbeat conversations always go to the dedicated heartbeat workspace, regardless of the configured workspace", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    // Two DIFFERENT workspaces each configure a heartbeat.
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    await svc.updateConfig("ws-2", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });

    advance(60_000); // both fire (1-minute interval)
    await flush();
    expect(orch.pending).toHaveLength(2);
    // Every spawned conversation is filed in the heartbeat workspace —
    // NOT ws-1 or ws-2 — so heartbeat runs don't clog either workspace's
    // tabs. The run history, however, stays tracked per configured workspace.
    for (const turn of orch.pending) {
      expect(turn.workspaceId).toBe("heartbeat");
    }
    // Run history is still per configured workspace.
    expect((await svc.listRuns("ws-1"))[0]?.status).toBe("running");
    expect((await svc.listRuns("ws-2"))[0]?.status).toBe("running");
    for (const turn of orch.pending) {
      turn.resolve();
    }
    await flush();
  });

  it("the turn cwd is pinned to the CONFIGURED workspace's defaultCwd (not the heartbeat workspace's empty defaultCwd)", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({
      orch,
      // The configured workspace has a defaultCwd.
      getWorkspaceCwd: (wsId) => Promise.resolve(wsId === "ws-1" ? "/home/proj/ws-1" : null),
    });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    // The conversation is filed in the heartbeat workspace …
    expect(turn.workspaceId).toBe("heartbeat");
    // … but the turn's cwd is the CONFIGURED workspace's defaultCwd, so
    // tools run where the prompt's [prompt:cwd] advertises (not the
    // heartbeat workspace's empty defaultCwd → process.cwd()).
    expect(turn.cwd).toBe("/home/proj/ws-1");
    turn.resolve();
    await flush();
  });

  it("omits the cwd override when the configured workspace has no defaultCwd (orchestrator falls back to the server default)", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({
      orch,
      // The configured workspace has NO defaultCwd.
      getWorkspaceCwd: () => Promise.resolve(null),
    });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    expect(turn.workspaceId).toBe("heartbeat");
    // No cwd override sent — the orchestrator resolves the turn cwd from
    // the heartbeat workspace (no defaultCwd → server default cwd).
    expect(turn.cwd).toBeUndefined();
    turn.resolve();
    await flush();
  });

  it("omits the cwd override when getWorkspaceCwd is not wired (resolution is optional)", async () => {
    const orch = createFakeOrchestrator();
    // No getWorkspaceCwd → no cwd override (the default).
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    expect(turn.workspaceId).toBe("heartbeat");
    expect(turn.cwd).toBeUndefined();
    turn.resolve();
    await flush();
  });

  it("omits modelName/reasoningEffort when empty/null (inherit defaults)", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", {
      enabled: true,
      taskPrompt: "go",
      model: "",
      reasoningEffort: null,
      intervalMinutes: 1,
    });
    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    expect(turn.modelName).toBeUndefined();
    expect(turn.reasoningEffort).toBeUndefined();
    turn.resolve();
    await flush();
  });

  it("resolves [type:name] variables in both systemPrompt and taskPrompt before sending", async () => {
    const orch = createFakeOrchestrator();
    // A fake resolver that mirrors the real resolver's contract: substitute
    // known [type:name] placeholders, leave unknown text verbatim.
    const resolvePrompt = async (
      template: string,
      ctx: {
        readonly workspaceId: string;
        readonly conversationId: string;
        readonly model: string;
      },
    ): Promise<string> => {
      return template
        .replaceAll("[system:os]", "Linux (WSL)")
        .replaceAll("[prompt:cwd]", "/repo")
        .replaceAll("[prompt:workspace_id]", ctx.workspaceId)
        .replaceAll("[prompt:conversation_id]", ctx.conversationId)
        .replaceAll("[prompt:model]", ctx.model);
    };
    const { svc, advance } = createService({ orch, resolvePrompt });
    await svc.updateConfig("ws-1", {
      enabled: true,
      systemPrompt: "You run on [system:os] in [prompt:cwd] (ws [prompt:workspace_id]).",
      taskPrompt: "Check chats for [prompt:conversation_id] on [system:os].",
      model: "opencode/gpt-4o",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    expect(orch.pending).toHaveLength(1);
    const turn = orch.pending[0]!;
    // Variables substituted — NOT left as literal [type:name] text.
    expect(turn.systemPrompt).toBe("You run on Linux (WSL) in /repo (ws ws-1).");
    expect(turn.text).toBe(`Check chats for ${turn.conversationId} on Linux (WSL).`);
    expect(turn.modelName).toBe("opencode/gpt-4o");
    turn.resolve();
    await flush();
  });

  it("passes prompts through raw when no resolver is wired (resolution is optional)", async () => {
    const orch = createFakeOrchestrator();
    // No resolvePrompt → raw pass-through (the default).
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", {
      enabled: true,
      systemPrompt: "raw [system:os] prompt",
      taskPrompt: "raw [system:date] task",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    // Unresolved — literals reach the orchestrator verbatim.
    expect(turn.systemPrompt).toBe("raw [system:os] prompt");
    expect(turn.text).toBe("raw [system:date] task");
    turn.resolve();
    await flush();
  });

  it("an empty systemPrompt inherits the global system prompt template (CR-HB-2)", async () => {
    const orch = createFakeOrchestrator();
    // The global getter returns the workspace's regular system prompt
    // template (the same one GET /system-prompt returns). No resolver → the
    // inherited template reaches the orchestrator verbatim (isolates CR-HB-2
    // from CR-HB-1).
    const { svc, advance } = createService({
      orch,
      getGlobalSystemPrompt: () => Promise.resolve("GLOBAL DEFAULT TEMPLATE"),
    });
    await svc.updateConfig("ws-1", {
      enabled: true,
      // Empty systemPrompt = inherit the global default, NOT "no prompt".
      systemPrompt: "",
      taskPrompt: "go",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    expect(orch.pending).toHaveLength(1);
    const turn = orch.pending[0]!;
    expect(turn.systemPrompt).toBe("GLOBAL DEFAULT TEMPLATE");
    turn.resolve();
    await flush();
  });

  it("CR-HB-2 composes with CR-HB-1: the inherited global template's [type:name] placeholders are resolved", async () => {
    const orch = createFakeOrchestrator();
    const resolvePrompt = async (
      template: string,
      ctx: {
        readonly workspaceId: string;
        readonly conversationId: string;
        readonly model: string;
      },
    ): Promise<string> => {
      return template
        .replaceAll("[system:os]", "Linux (WSL)")
        .replaceAll("[prompt:cwd]", "/repo")
        .replaceAll("[prompt:workspace_id]", ctx.workspaceId);
    };
    // The global template carries [type:name] placeholders (like the real
    // default template embeds [prompt:cwd] / [file:AGENTS.md]).
    const { svc, advance } = createService({
      orch,
      resolvePrompt,
      getGlobalSystemPrompt: () =>
        Promise.resolve("You run on [system:os] in [prompt:cwd] (ws [prompt:workspace_id])."),
    });
    await svc.updateConfig("ws-1", {
      enabled: true,
      // Empty → inherit the global template, THEN resolve its placeholders.
      systemPrompt: "",
      taskPrompt: "go",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    expect(orch.pending).toHaveLength(1);
    const turn = orch.pending[0]!;
    // The global template was inherited (not empty), then its [type:name]
    // placeholders were substituted — NOT left literal, NOT empty.
    expect(turn.systemPrompt).toBe("You run on Linux (WSL) in /repo (ws ws-1).");
    turn.resolve();
    await flush();
  });

  it("a non-empty systemPrompt override bypasses the global template (only CR-HB-1 applies)", async () => {
    const orch = createFakeOrchestrator();
    const resolvePrompt = async (template: string): Promise<string> =>
      template.replaceAll("[system:os]", "Linux (WSL)");
    const { svc, advance } = createService({
      orch,
      resolvePrompt,
      // A DISTINCT global template — must NOT be used when overriding.
      getGlobalSystemPrompt: () => Promise.resolve("GLOBAL SHOULD NOT APPEAR [system:os]"),
    });
    await svc.updateConfig("ws-1", {
      enabled: true,
      systemPrompt: "custom override on [system:os]",
      taskPrompt: "go",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    // The override is used (and resolved), not the global template.
    expect(turn.systemPrompt).toBe("custom override on Linux (WSL)");
    turn.resolve();
    await flush();
  });

  it("an empty systemPrompt stays empty when no global getter is wired (resolution is optional)", async () => {
    const orch = createFakeOrchestrator();
    // No getGlobalSystemPrompt → empty stays empty (no system prompt).
    // Mirrors the no-resolver pass-through default: both deps are optional.
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", {
      enabled: true,
      systemPrompt: "",
      taskPrompt: "go",
      intervalMinutes: 1,
    });

    advance(60_000);
    await flush();
    const turn = orch.pending[0]!;
    expect(turn.systemPrompt).toBe("");
    turn.resolve();
    await flush();
  });

  it("stopRun aborts the turn and marks the run stopped (not overwritten on completion)", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    advance(60_000);
    await flush();
    const conversationId = orch.pending[0]?.conversationId;
    const runId = (await svc.listRuns("ws-1"))[0]?.id;

    const res = await svc.stopRun("ws-1", runId);
    expect(res).toEqual({ ok: true });
    expect(orch.stopped).toEqual([conversationId]);

    await flush(); // the aborted turn's handleMessage resolves
    expect((await svc.listRuns("ws-1"))[0]?.status).toBe("stopped");
  });

  it("stopRun is idempotent for an already-finished run", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    advance(60_000);
    await flush();
    orch.pending[0]?.resolve();
    await flush();

    const runId = (await svc.listRuns("ws-1"))[0]?.id;
    const res = await svc.stopRun("ws-1", runId);
    expect(res).toEqual({ ok: true });
    expect(orch.stopped).toEqual([]); // no abort on a completed run
  });

  it("stopRun throws for an unknown run id", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    await expect(svc.stopRun("ws-1", "nope")).rejects.toThrow();
  });

  it("disabling the config stops the schedule (no further fires)", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go" });
    await svc.updateConfig("ws-1", { enabled: false });
    advance(60_000);
    expect(orch.pending).toHaveLength(0);
  });

  it("startAll sweeps stale running runs to stopped", async () => {
    const storage = createMemoryStorage();
    await storage.set(
      "run:ws-1:stale",
      JSON.stringify({
        id: "stale",
        conversationId: "c-stale",
        triggeredAt: "2026-01-01T00:00:00.000Z",
        status: "running",
      }),
    );
    await storage.set(
      "config:ws-1",
      JSON.stringify({
        enabled: false,
        systemPrompt: "",
        taskPrompt: "",
        intervalMinutes: 30,
        model: "",
        reasoningEffort: null,
      }),
    );

    const { svc } = createService({ orch: createFakeOrchestrator(), storage });
    await svc.startAll();
    expect((await svc.listRuns("ws-1"))[0]?.status).toBe("stopped");
  });

  it("startAll arms enabled workspaces and skips disabled ones", async () => {
    const orch = createFakeOrchestrator();
    const { svc: svc1, storage } = createService({ orch });
    await svc1.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    await svc1.updateConfig("ws-2", { enabled: false, taskPrompt: "no" });
    svc1.stopAll();

    // Re-create a fresh service over the SAME storage (simulates a reboot),
    // with new fake timers we can advance.
    const fake = createFakeTimers();
    let id = 1000;
    const svc2 = createHeartbeatService({
      storage,
      orchestrator: orch,
      timers: fake.timers,
      generateId: () => `id-${++id}`,
    });
    await svc2.startAll();
    fake.advance(60_000);
    await flush();
    // ws-1 (enabled) fired → its spawned conversation is filed in the
    // heartbeat workspace; ws-2 (disabled) never fired.
    expect(orch.pending).toHaveLength(1);
    expect(orch.pending[0]?.workspaceId).toBe("heartbeat");
  });

  // ─── nextRunAt (CR-HB-3: server-authoritative next-run time) ────────────────

  it("nextRunAt returns null when the heartbeat is disabled", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    // Default config → disabled → no schedule armed.
    expect(await svc.nextRunAt("ws-1")).toBeNull();
  });

  it("nextRunAt returns the ISO timestamp of the next fire when enabled", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    // now=0, interval=1m → next fire at epoch-ms 60_000 → its ISO form.
    expect(await svc.nextRunAt("ws-1")).toBe(new Date(60_000).toISOString());
  });

  it("nextRunAt returns null while a run is in progress, then the next fire after it completes", async () => {
    const orch = createFakeOrchestrator();
    const { svc, advance } = createService({ orch });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    expect(await svc.nextRunAt("ws-1")).toBe(new Date(60_000).toISOString());

    advance(60_000); // fire → run in progress
    await flush();
    expect(orch.pending).toHaveLength(1);
    // In flight → no next run queued yet.
    expect(await svc.nextRunAt("ws-1")).toBeNull();

    orch.pending[0]?.resolve();
    await flush();
    // Re-armed at completion-time (60_000) + interval (60_000) = 120_000.
    expect(await svc.nextRunAt("ws-1")).toBe(new Date(120_000).toISOString());
  });

  it("nextRunAt returns null after disabling the heartbeat", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    expect(await svc.nextRunAt("ws-1")).not.toBeNull();
    await svc.updateConfig("ws-1", { enabled: false });
    expect(await svc.nextRunAt("ws-1")).toBeNull();
  });

  it("nextRunAt reflects a changed interval on the next re-arm", async () => {
    const { svc } = createService({ orch: createFakeOrchestrator() });
    await svc.updateConfig("ws-1", { enabled: true, taskPrompt: "go", intervalMinutes: 1 });
    expect(await svc.nextRunAt("ws-1")).toBe(new Date(60_000).toISOString());
    // Re-arm with a 5-minute interval (not running) → recomputed fire time.
    await svc.updateConfig("ws-1", { intervalMinutes: 5 });
    expect(await svc.nextRunAt("ws-1")).toBe(new Date(5 * 60_000).toISOString());
  });
});