import { describe, it, expect, beforeEach, afterEach } from "vitest";
import { mkdtemp, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { FileTaskStore } from "./task-store.js";

let tempDir: string;
let store: FileTaskStore;

beforeEach(async () => {
  tempDir = await mkdtemp(join(tmpdir(), "task-store-test-"));
  store = new FileTaskStore(tempDir);
});

afterEach(async () => {
  await rm(tempDir, { recursive: true, force: true });
});

describe("create", () => {
  it("creates a task with default status open", async () => {
    const task = await store.create("My first task");

    expect(task.id).toMatch(/^[a-f0-9]{8}$/);
    expect(task.title).toBe("My first task");
    expect(task.status).toBe("open");
    expect(task.deps).toEqual([]);
    expect(task.parentId).toBeUndefined();
    expect(task.body).toBe("");
    expect(task.notes).toEqual([]);
    expect(task.created).toMatch(/^\d{4}-\d{2}-\d{2}T/);
    expect(task.assignee).toBeUndefined();
    expect(task.priority).toBeUndefined();
  });

  it("creates a task with priority", async () => {
    const task = await store.create("High priority task", { priority: 1 });

    expect(task.priority).toBe(1);
  });

  it("creates a task with custom status", async () => {
    const task = await store.create("Draft task", { status: "draft" });

    expect(task.status).toBe("draft");
  });

  it("creates a task with dependencies", async () => {
    const dep1 = await store.create("Dependency 1");
    const dep2 = await store.create("Dependency 2");
    const task = await store.create("Main task", {
      deps: [dep1.id, dep2.id],
    });

    expect(task.deps).toEqual([dep1.id, dep2.id]);
  });

  it("creates a task with body", async () => {
    const task = await store.create("Task with body", {
      body: "This is a **long** body\n\nWith multiple lines.",
    });

    expect(task.body).toBe("This is a **long** body\n\nWith multiple lines.");
  });

  it("creates a task with parentId", async () => {
    const parent = await store.create("Parent task");
    const child = await store.create("Child task", { parentId: parent.id });

    expect(child.parentId).toBe(parent.id);
  });

  it("throws when creating task with non-existent parent", async () => {
    await expect(store.create("Child", { parentId: "nonexistent" })).rejects.toThrow(
      "Parent task not found",
    );
  });

  it("creates a task with assignee", async () => {
    const task = await store.create("Task for Claude", {
      assignee: "claude",
    });

    expect(task.assignee).toBe("claude");
  });

  it("generates unique IDs for each task", async () => {
    const task1 = await store.create("Task 1");
    const task2 = await store.create("Task 2");
    const task3 = await store.create("Task 3");

    const ids = [task1.id, task2.id, task3.id];
    expect(new Set(ids).size).toBe(3);
  });

  it("sets created timestamp", async () => {
    const before = new Date().toISOString();
    const task = await store.create("Task");
    const after = new Date().toISOString();

    expect(task.created >= before).toBe(true);
    expect(task.created <= after).toBe(true);
  });

  it("returns task with raw content", async () => {
    const task = await store.create("Test task", {
      body: "Task body here",
      acceptanceCriteria: ["criterion 1", "criterion 2"],
    });

    expect(task.raw).toContain("---");
    expect(task.raw).toContain("title: Test task");
    expect(task.raw).toContain("Task body here");
    expect(task.raw).toContain("## Acceptance Criteria");
    expect(task.raw).toContain("criterion 1");
    expect(task.raw).toContain("criterion 2");
  });
});

describe("get", () => {
  it("returns task by id", async () => {
    const created = await store.create("Test task");
    const retrieved = await store.get(created.id);

    expect(retrieved).toEqual(created);
  });

  it("returns null for non-existent task", async () => {
    const result = await store.get("nonexistent");

    expect(result).toBeNull();
  });

  it("preserves assignee field", async () => {
    const created = await store.create("Task", { assignee: "codex" });
    const retrieved = await store.get(created.id);

    expect(retrieved?.assignee).toBe("codex");
  });

  it("returns raw content matching the file", async () => {
    const created = await store.create("Task with body", {
      body: "Some body content",
      acceptanceCriteria: ["test passes", "lint passes"],
    });
    await store.addNote(created.id, "A note was added");

    const retrieved = await store.get(created.id);

    expect(retrieved?.raw).toContain("title: Task with body");
    expect(retrieved?.raw).toContain("Some body content");
    expect(retrieved?.raw).toContain("## Acceptance Criteria");
    expect(retrieved?.raw).toContain("test passes");
    expect(retrieved?.raw).toContain("lint passes");
    expect(retrieved?.raw).toContain("## Notes");
    expect(retrieved?.raw).toContain("A note was added");
  });
});

describe("list", () => {
  it("returns empty array when no tasks", async () => {
    const tasks = await store.list();

    expect(tasks).toEqual([]);
  });

  it("returns all tasks", async () => {
    await store.create("Task 1");
    await store.create("Task 2");
    await store.create("Task 3");

    const tasks = await store.list();

    expect(tasks).toHaveLength(3);
    expect(tasks.map((t) => t.title).sort()).toEqual(["Task 1", "Task 2", "Task 3"]);
  });
});

describe("update", () => {
  it("updates task title", async () => {
    const task = await store.create("Original title");
    const updated = await store.update(task.id, { title: "New title" });

    expect(updated.title).toBe("New title");
    expect(updated.id).toBe(task.id);
  });

  it("updates task body", async () => {
    const task = await store.create("Task");
    const updated = await store.update(task.id, {
      body: "New body",
    });

    expect(updated.body).toBe("New body");
  });

  it("updates task assignee", async () => {
    const task = await store.create("Task");
    const updated = await store.update(task.id, { assignee: "claude" });

    expect(updated.assignee).toBe("claude");
  });

  it("persists updates", async () => {
    const task = await store.create("Task");
    await store.update(task.id, { title: "Updated" });

    const retrieved = await store.get(task.id);
    expect(retrieved?.title).toBe("Updated");
  });

  it("preserves created timestamp on update", async () => {
    const task = await store.create("Task");
    const originalCreated = task.created;

    await new Promise((r) => setTimeout(r, 10));
    await store.update(task.id, { title: "Updated" });

    const retrieved = await store.get(task.id);
    expect(retrieved?.created).toBe(originalCreated);
  });

  it("throws for non-existent task", async () => {
    await expect(store.update("nonexistent", { title: "New" })).rejects.toThrow();
  });

  it("replaces acceptance criteria", async () => {
    const task = await store.create("Task", {
      acceptanceCriteria: ["old criterion 1", "old criterion 2"],
    });

    const updated = await store.update(task.id, {
      acceptanceCriteria: ["new criterion"],
    });

    expect(updated.acceptanceCriteria).toEqual(["new criterion"]);
  });

  it("clears acceptance criteria with empty array", async () => {
    const task = await store.create("Task", {
      acceptanceCriteria: ["criterion 1", "criterion 2"],
    });

    const updated = await store.update(task.id, {
      acceptanceCriteria: [],
    });

    expect(updated.acceptanceCriteria).toEqual([]);
  });
});

describe("delete", () => {
  it("deletes a task", async () => {
    const task = await store.create("Task to delete");
    await store.delete(task.id);

    const retrieved = await store.get(task.id);
    expect(retrieved).toBeNull();
  });

  it("removes task from list", async () => {
    const task1 = await store.create("Task 1");
    const task2 = await store.create("Task 2");
    await store.delete(task1.id);

    const tasks = await store.list();
    expect(tasks).toHaveLength(1);
    expect(tasks[0].id).toBe(task2.id);
  });

  it("throws for non-existent task", async () => {
    await expect(store.delete("nonexistent")).rejects.toThrow();
  });
});

describe("status transitions", () => {
  it("transitions draft to open", async () => {
    const task = await store.create("Draft", { status: "draft" });
    await store.open(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("open");
  });

  it("reopens a done task", async () => {
    const task = await store.create("Task");
    await store.close(task.id);
    await store.open(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("open");
  });

  it("reopens a failed task", async () => {
    const task = await store.create("Task");
    await store.fail(task.id);
    await store.open(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("open");
  });

  it("reopens an in_progress task", async () => {
    const task = await store.create("Task");
    await store.start(task.id);
    await store.open(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("open");
  });

  it("is idempotent for already open task", async () => {
    const task = await store.create("Task");
    await store.open(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("open");
  });

  it("transitions open to in_progress", async () => {
    const task = await store.create("Task");
    await store.start(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("in_progress");
  });

  it("throws when task is draft", async () => {
    const task = await store.create("Draft", { status: "draft" });

    await expect(store.start(task.id)).rejects.toThrow();
  });

  it("throws when task is already done", async () => {
    const task = await store.create("Task");
    await store.close(task.id);

    await expect(store.start(task.id)).rejects.toThrow();
  });

  it("transitions open to done", async () => {
    const task = await store.create("Task");
    await store.close(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("done");
  });

  it("transitions in_progress to done", async () => {
    const task = await store.create("Task");
    await store.start(task.id);
    await store.close(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("done");
  });

  it("transitions draft to done", async () => {
    const task = await store.create("Task", { status: "draft" });
    await store.close(task.id);

    const updated = await store.get(task.id);
    expect(updated?.status).toBe("done");
  });
});

describe("dependencies", () => {
  it("adds a dependency", async () => {
    const dep = await store.create("Dependency");
    const task = await store.create("Task");

    await store.addDep(task.id, dep.id);

    const updated = await store.get(task.id);
    expect(updated?.deps).toContain(dep.id);
  });

  it("does not duplicate dependencies", async () => {
    const dep = await store.create("Dependency");
    const task = await store.create("Task");

    await store.addDep(task.id, dep.id);
    await store.addDep(task.id, dep.id);

    const updated = await store.get(task.id);
    expect(updated?.deps).toEqual([dep.id]);
  });

  it("throws for non-existent task", async () => {
    const dep = await store.create("Dependency");

    await expect(store.addDep("nonexistent", dep.id)).rejects.toThrow();
  });

  it("throws for non-existent dependency", async () => {
    const task = await store.create("Task");

    await expect(store.addDep(task.id, "nonexistent")).rejects.toThrow();
  });

  it("removes a dependency", async () => {
    const dep = await store.create("Dependency");
    const task = await store.create("Task", { deps: [dep.id] });

    await store.removeDep(task.id, dep.id);

    const updated = await store.get(task.id);
    expect(updated?.deps).toEqual([]);
  });

  it("is idempotent for non-existent dep", async () => {
    const task = await store.create("Task");

    await store.removeDep(task.id, "nonexistent");

    const updated = await store.get(task.id);
    expect(updated?.deps).toEqual([]);
  });
});

describe("notes", () => {
  it("adds a note with timestamp", async () => {
    const task = await store.create("Task");
    const before = new Date().toISOString();

    await store.addNote(task.id, "This is a note");

    const updated = await store.get(task.id);
    expect(updated?.notes).toHaveLength(1);
    expect(updated?.notes[0].content).toBe("This is a note");
    expect(updated?.notes[0].timestamp >= before).toBe(true);
  });

  it("appends multiple notes in order", async () => {
    const task = await store.create("Task");

    await store.addNote(task.id, "First note");
    await store.addNote(task.id, "Second note");
    await store.addNote(task.id, "Third note");

    const updated = await store.get(task.id);
    expect(updated?.notes).toHaveLength(3);
    expect(updated?.notes.map((n) => n.content)).toEqual([
      "First note",
      "Second note",
      "Third note",
    ]);
  });
});

describe("getReady", () => {
  it("returns open tasks with no deps", async () => {
    const task = await store.create("Ready task");

    const ready = await store.getReady();

    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(task.id);
  });

  it("excludes draft tasks", async () => {
    await store.create("Draft task", { status: "draft" });

    const ready = await store.getReady();

    expect(ready).toHaveLength(0);
  });

  it("excludes in_progress tasks", async () => {
    const task = await store.create("Task");
    await store.start(task.id);

    const ready = await store.getReady();

    expect(ready).toHaveLength(0);
  });

  it("excludes done tasks", async () => {
    const task = await store.create("Task");
    await store.close(task.id);

    const ready = await store.getReady();

    expect(ready).toHaveLength(0);
  });

  it("excludes tasks with unresolved deps", async () => {
    const dep = await store.create("Dependency");
    await store.create("Blocked task", { deps: [dep.id] });

    const ready = await store.getReady();

    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(dep.id);
  });

  it("includes tasks when all deps are done", async () => {
    const dep = await store.create("Dependency");
    const task = await store.create("Task", { deps: [dep.id] });
    await store.close(dep.id);

    const ready = await store.getReady();

    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(task.id);
  });

  it("handles multiple deps correctly", async () => {
    const dep1 = await store.create("Dep 1");
    const dep2 = await store.create("Dep 2");
    const task = await store.create("Task", { deps: [dep1.id, dep2.id] });

    // Only one dep done - task not ready
    await store.close(dep1.id);
    let ready = await store.getReady();
    expect(ready.map((t) => t.id)).not.toContain(task.id);

    // Both deps done - task ready
    await store.close(dep2.id);
    ready = await store.getReady();
    expect(ready.map((t) => t.id)).toContain(task.id);
  });

  it("sorts by created date (oldest first) when no priority", async () => {
    const task1 = await store.create("Task 1");
    await new Promise((r) => setTimeout(r, 10));
    const task2 = await store.create("Task 2");
    await new Promise((r) => setTimeout(r, 10));
    const task3 = await store.create("Task 3");

    const ready = await store.getReady();

    expect(ready.map((t) => t.id)).toEqual([task1.id, task2.id, task3.id]);
  });

  it("sorts by priority first (lower number = higher priority)", async () => {
    // Create in wrong order to prove priority wins over creation time
    const low = await store.create("Low priority", { priority: 10 });
    const high = await store.create("High priority", { priority: 1 });
    const medium = await store.create("Medium priority", { priority: 5 });

    const ready = await store.getReady();

    expect(ready.map((t) => t.id)).toEqual([high.id, medium.id, low.id]);
  });

  it("tasks with priority come before tasks without", async () => {
    // Create without priority first to prove priority wins
    const noPriority = await store.create("No priority");
    const withPriority = await store.create("With priority", { priority: 5 });

    const ready = await store.getReady();

    expect(ready.map((t) => t.id)).toEqual([withPriority.id, noPriority.id]);
  });

  it("sorts by created date within same priority", async () => {
    const first = await store.create("First", { priority: 1 });
    await new Promise((r) => setTimeout(r, 10));
    const second = await store.create("Second", { priority: 1 });
    await new Promise((r) => setTimeout(r, 10));
    const third = await store.create("Third", { priority: 1 });

    const ready = await store.getReady();

    expect(ready.map((t) => t.id)).toEqual([first.id, second.id, third.id]);
  });

  it("excludes parent task when it has open children", async () => {
    const parent = await store.create("Parent task");
    await store.create("Child 1", { parentId: parent.id });
    await store.create("Child 2", { parentId: parent.id });

    const ready = await store.getReady();

    // Children are ready but parent is not (has open children)
    expect(ready).toHaveLength(2);
    expect(ready.map((t) => t.id)).not.toContain(parent.id);
  });

  it("includes parent task when all children are done", async () => {
    const parent = await store.create("Parent task");
    const child1 = await store.create("Child 1", { parentId: parent.id });
    const child2 = await store.create("Child 2", { parentId: parent.id });

    await store.close(child1.id);
    await store.close(child2.id);

    const ready = await store.getReady();

    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(parent.id);
  });

  it("excludes parent when some children are not done", async () => {
    const parent = await store.create("Parent task");
    const child1 = await store.create("Child 1", { parentId: parent.id });
    await store.create("Child 2", { parentId: parent.id });

    await store.close(child1.id);

    const ready = await store.getReady();

    // Only child2 is ready, parent is blocked by child2
    expect(ready).toHaveLength(1);
    expect(ready.map((t) => t.id)).not.toContain(parent.id);
  });

  it("handles nested children - parent waits for all descendants", async () => {
    const parent = await store.create("Parent");
    const child = await store.create("Child", { parentId: parent.id });
    const grandchild = await store.create("Grandchild", {
      parentId: child.id,
    });

    // Only grandchild is ready (no children)
    let ready = await store.getReady();
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(grandchild.id);

    // After grandchild done, child becomes ready
    await store.close(grandchild.id);
    ready = await store.getReady();
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(child.id);

    // After child done, parent becomes ready
    await store.close(child.id);
    ready = await store.getReady();
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(parent.id);
  });

  it("combines deps and children blocking", async () => {
    const dep = await store.create("Dependency");
    const parent = await store.create("Parent", { deps: [dep.id] });
    const child = await store.create("Child", { parentId: parent.id });

    // Only dep and child are ready (parent blocked by both dep and child)
    let ready = await store.getReady();
    expect(ready).toHaveLength(2);
    expect(ready.map((t) => t.id)).toContain(dep.id);
    expect(ready.map((t) => t.id)).toContain(child.id);
    expect(ready.map((t) => t.id)).not.toContain(parent.id);

    // Close child but not dep - parent still blocked
    await store.close(child.id);
    ready = await store.getReady();
    expect(ready.map((t) => t.id)).not.toContain(parent.id);

    // Close dep - now parent is ready
    await store.close(dep.id);
    ready = await store.getReady();
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(parent.id);
  });

  it("task with no children is ready (leaf task)", async () => {
    const task = await store.create("Leaf task");

    const ready = await store.getReady();

    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(task.id);
  });

  it("returns only ready tasks in epic children tree", async () => {
    await store.create("Unrelated task");
    const epic = await store.create("Epic");
    const child = await store.create("Epic child", { parentId: epic.id });

    const ready = await store.getReady(epic.id);

    // Only child is ready (epic blocked by its open child)
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(child.id);

    // After closing child, epic becomes ready
    await store.close(child.id);
    const readyAfter = await store.getReady(epic.id);
    expect(readyAfter).toHaveLength(1);
    expect(readyAfter[0].id).toBe(epic.id);
  });

  it("returns empty when epic and children are not ready", async () => {
    const epic = await store.create("Epic", { status: "draft" });
    await store.create("Child", { parentId: epic.id, status: "draft" });

    const ready = await store.getReady(epic.id);

    expect(ready).toHaveLength(0);
  });

  it("handles nested children", async () => {
    const epic = await store.create("Epic");
    const child = await store.create("Child", { parentId: epic.id });
    const grandchild = await store.create("Grandchild", {
      parentId: child.id,
    });

    // Only grandchild is ready (leaf node)
    let ready = await store.getReady(epic.id);
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(grandchild.id);

    // After closing grandchild, child becomes ready
    await store.close(grandchild.id);
    ready = await store.getReady(epic.id);
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(child.id);

    // After closing child, epic becomes ready
    await store.close(child.id);
    ready = await store.getReady(epic.id);
    expect(ready).toHaveLength(1);
    expect(ready[0].id).toBe(epic.id);
  });
});

describe("getBlocked", () => {
  it("returns tasks with unresolved deps", async () => {
    const dep = await store.create("Dependency");
    const blocked = await store.create("Blocked", { deps: [dep.id] });

    const result = await store.getBlocked();

    expect(result).toHaveLength(1);
    expect(result[0].id).toBe(blocked.id);
  });

  it("excludes tasks with no deps", async () => {
    await store.create("No deps");

    const result = await store.getBlocked();

    expect(result).toHaveLength(0);
  });

  it("excludes tasks with all deps done", async () => {
    const dep = await store.create("Dep");
    await store.create("Task", { deps: [dep.id] });
    await store.close(dep.id);

    const result = await store.getBlocked();

    expect(result).toHaveLength(0);
  });

  it("excludes draft tasks", async () => {
    const dep = await store.create("Dep");
    await store.create("Draft blocked", { status: "draft", deps: [dep.id] });

    const result = await store.getBlocked();

    expect(result).toHaveLength(0);
  });

  it("includes in_progress tasks with unresolved deps", async () => {
    const dep = await store.create("Dep");
    const task = await store.create("Task", { deps: [dep.id] });
    // Force start even with unresolved deps (edge case)
    await store.update(task.id, { status: "in_progress" });

    const result = await store.getBlocked();

    expect(result).toHaveLength(1);
    expect(result[0].id).toBe(task.id);
  });

  it("returns only blocked tasks in epic children tree", async () => {
    const unrelatedDep = await store.create("Unrelated dep");
    await store.create("Unrelated blocked", {
      deps: [unrelatedDep.id],
    });

    const epic = await store.create("Epic");
    const externalDep = await store.create("External dep");
    const blockedChild = await store.create("Blocked child", {
      parentId: epic.id,
      deps: [externalDep.id],
    });

    const blocked = await store.getBlocked(epic.id);

    expect(blocked).toHaveLength(1);
    expect(blocked[0].id).toBe(blockedChild.id);
  });
});

describe("getClosed", () => {
  it("returns done tasks", async () => {
    const task = await store.create("Task");
    await store.close(task.id);

    const closed = await store.getClosed();

    expect(closed).toHaveLength(1);
    expect(closed[0].id).toBe(task.id);
  });

  it("excludes non-done tasks", async () => {
    await store.create("Open task");
    await store.create("Draft task", { status: "draft" });
    const inProgress = await store.create("In progress");
    await store.start(inProgress.id);

    const closed = await store.getClosed();

    expect(closed).toHaveLength(0);
  });

  it("sorts by created date (most recent first)", async () => {
    const task1 = await store.create("Task 1");
    await new Promise((r) => setTimeout(r, 10));
    const task2 = await store.create("Task 2");
    await new Promise((r) => setTimeout(r, 10));
    const task3 = await store.create("Task 3");

    await store.close(task1.id);
    await store.close(task2.id);
    await store.close(task3.id);

    const closed = await store.getClosed();

    expect(closed.map((t) => t.id)).toEqual([task3.id, task2.id, task1.id]);
  });

  it("returns only closed tasks in epic children tree", async () => {
    const unrelated = await store.create("Unrelated");
    await store.close(unrelated.id);

    const epic = await store.create("Epic");
    const child = await store.create("Epic child", { parentId: epic.id });
    await store.close(child.id);

    const closed = await store.getClosed(epic.id);

    // Only the closed child is returned (epic is still open)
    expect(closed).toHaveLength(1);
    expect(closed[0].id).toBe(child.id);
  });
});

describe("getDepTree", () => {
  it("returns empty for task with no deps", async () => {
    const task = await store.create("Leaf task");

    const tree = await store.getDepTree(task.id);

    expect(tree).toEqual([]);
  });

  it("returns direct deps", async () => {
    const dep1 = await store.create("Dep 1");
    const dep2 = await store.create("Dep 2");
    const task = await store.create("Task", { deps: [dep1.id, dep2.id] });

    const tree = await store.getDepTree(task.id);

    expect(tree).toHaveLength(2);
    expect(tree.map((t) => t.id).sort()).toEqual([dep1.id, dep2.id].sort());
  });

  it("returns nested deps recursively", async () => {
    const leaf = await store.create("Leaf");
    const middle = await store.create("Middle", { deps: [leaf.id] });
    const root = await store.create("Root", { deps: [middle.id] });

    const tree = await store.getDepTree(root.id);

    expect(tree).toHaveLength(2);
    expect(tree.map((t) => t.id).sort()).toEqual([leaf.id, middle.id].sort());
  });

  it("handles diamond deps without duplicates", async () => {
    const shared = await store.create("Shared");
    const left = await store.create("Left", { deps: [shared.id] });
    const right = await store.create("Right", { deps: [shared.id] });
    const root = await store.create("Root", { deps: [left.id, right.id] });

    const tree = await store.getDepTree(root.id);

    expect(tree).toHaveLength(3);
    expect(tree.map((t) => t.id).sort()).toEqual([shared.id, left.id, right.id].sort());
  });

  it("handles circular deps gracefully", async () => {
    const task1 = await store.create("Task 1");
    const task2 = await store.create("Task 2", { deps: [task1.id] });
    await store.addDep(task1.id, task2.id); // create cycle

    // Should not infinite loop
    const tree = await store.getDepTree(task1.id);

    expect(tree.map((t) => t.id)).toContain(task2.id);
  });

  it("throws for non-existent task", async () => {
    await expect(store.getDepTree("nonexistent")).rejects.toThrow();
  });
});

describe("file persistence", () => {
  it("persists tasks across store instances", async () => {
    const task = await store.create("Persistent task", {
      body: "With body",
      assignee: "claude",
    });
    await store.addNote(task.id, "A note");

    // Create new store instance pointing to same dir
    const store2 = new FileTaskStore(tempDir);
    const retrieved = await store2.get(task.id);

    expect(retrieved).not.toBeNull();
    expect(retrieved?.title).toBe("Persistent task");
    expect(retrieved?.body).toBe("With body");
    expect(retrieved?.assignee).toBe("claude");
    expect(retrieved?.created).toBe(task.created);
    expect(retrieved?.notes).toHaveLength(1);
    expect(retrieved?.notes[0].content).toBe("A note");
  });

  it("persists parentId across store instances", async () => {
    const parent = await store.create("Parent");
    const child = await store.create("Child", { parentId: parent.id });

    const store2 = new FileTaskStore(tempDir);
    const retrieved = await store2.get(child.id);

    expect(retrieved?.parentId).toBe(parent.id);
  });

  it("persists priority across store instances", async () => {
    const task = await store.create("Priority task", { priority: 3 });

    const store2 = new FileTaskStore(tempDir);
    const retrieved = await store2.get(task.id);

    expect(retrieved?.priority).toBe(3);
  });

  it("persists raw content across store instances", async () => {
    const task = await store.create("Task with everything", {
      body: "Detailed body",
      acceptanceCriteria: ["tests pass", "build succeeds"],
      assignee: "claude",
      priority: 1,
    });
    await store.addNote(task.id, "Implementation note");

    const store2 = new FileTaskStore(tempDir);
    const retrieved = await store2.get(task.id);

    expect(retrieved?.raw).toContain("title: Task with everything");
    expect(retrieved?.raw).toContain("Detailed body");
    expect(retrieved?.raw).toContain("## Acceptance Criteria");
    expect(retrieved?.raw).toContain("tests pass");
    expect(retrieved?.raw).toContain("build succeeds");
    expect(retrieved?.raw).toContain("## Notes");
    expect(retrieved?.raw).toContain("Implementation note");
    expect(retrieved?.raw).toContain("assignee: claude");
    expect(retrieved?.raw).toContain("priority: 1");
  });
});

describe("parent-child hierarchy", () => {
  it("returns empty array for task with no parent", async () => {
    const task = await store.create("Root task");

    const ancestors = await store.getAncestors(task.id);

    expect(ancestors).toEqual([]);
  });

  it("returns parent for child task", async () => {
    const parent = await store.create("Parent");
    const child = await store.create("Child", { parentId: parent.id });

    const ancestors = await store.getAncestors(child.id);

    expect(ancestors).toHaveLength(1);
    expect(ancestors[0].id).toBe(parent.id);
  });

  it("returns full ancestor chain in order", async () => {
    const grandparent = await store.create("Grandparent");
    const parent = await store.create("Parent", {
      parentId: grandparent.id,
    });
    const child = await store.create("Child", { parentId: parent.id });

    const ancestors = await store.getAncestors(child.id);

    expect(ancestors).toHaveLength(2);
    expect(ancestors[0].id).toBe(parent.id);
    expect(ancestors[1].id).toBe(grandparent.id);
  });

  it("throws for non-existent task", async () => {
    await expect(store.getAncestors("nonexistent")).rejects.toThrow();
  });

  it("returns empty array for task with no children", async () => {
    const task = await store.create("Leaf task");

    const children = await store.getChildren(task.id);

    expect(children).toEqual([]);
  });

  it("returns direct children", async () => {
    const parent = await store.create("Parent");
    const child1 = await store.create("Child 1", { parentId: parent.id });
    const child2 = await store.create("Child 2", { parentId: parent.id });

    const children = await store.getChildren(parent.id);

    expect(children).toHaveLength(2);
    expect(children.map((c) => c.id).sort()).toEqual([child1.id, child2.id].sort());
  });

  it("does not return grandchildren", async () => {
    const grandparent = await store.create("Grandparent");
    const parent = await store.create("Parent", {
      parentId: grandparent.id,
    });
    await store.create("Grandchild", { parentId: parent.id });

    const children = await store.getChildren(grandparent.id);

    expect(children).toHaveLength(1);
    expect(children[0].id).toBe(parent.id);
  });

  it("sorts by priority first (lower number = higher priority)", async () => {
    const parent = await store.create("Parent");
    // Create in wrong order to prove priority wins over creation time
    const low = await store.create("Low priority child", {
      parentId: parent.id,
      priority: 10,
    });
    const high = await store.create("High priority child", {
      parentId: parent.id,
      priority: 1,
    });
    const medium = await store.create("Medium priority child", {
      parentId: parent.id,
      priority: 5,
    });

    const children = await store.getChildren(parent.id);

    expect(children.map((c) => c.id)).toEqual([high.id, medium.id, low.id]);
  });

  it("children with priority come before children without", async () => {
    const parent = await store.create("Parent");
    // Create without priority first to prove priority wins
    const noPriority = await store.create("No priority", {
      parentId: parent.id,
    });
    const withPriority = await store.create("With priority", {
      parentId: parent.id,
      priority: 5,
    });

    const children = await store.getChildren(parent.id);

    expect(children.map((c) => c.id)).toEqual([withPriority.id, noPriority.id]);
  });

  it("sets parent on a task", async () => {
    const parent = await store.create("Parent");
    const task = await store.create("Task");

    await store.setParent(task.id, parent.id);

    const updated = await store.get(task.id);
    expect(updated?.parentId).toBe(parent.id);
  });

  it("removes parent when set to null", async () => {
    const parent = await store.create("Parent");
    const task = await store.create("Task", { parentId: parent.id });

    await store.setParent(task.id, null);

    const updated = await store.get(task.id);
    expect(updated?.parentId).toBeUndefined();
  });

  it("throws for non-existent task", async () => {
    const parent = await store.create("Parent");

    await expect(store.setParent("nonexistent", parent.id)).rejects.toThrow("Task not found");
  });

  it("throws for non-existent parent", async () => {
    const task = await store.create("Task");

    await expect(store.setParent(task.id, "nonexistent")).rejects.toThrow("Parent task not found");
  });

  it("throws when setting task as its own parent", async () => {
    const task = await store.create("Task");

    await expect(store.setParent(task.id, task.id)).rejects.toThrow(
      "Task cannot be its own parent",
    );
  });

  it("throws when creating circular reference", async () => {
    const parent = await store.create("Parent");
    const child = await store.create("Child", { parentId: parent.id });

    await expect(store.setParent(parent.id, child.id)).rejects.toThrow("circular reference");
  });
});