import { describe, it, expect, afterEach, beforeEach } from "vitest";
import { mkdtempSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { DatabaseSync } from "node:sqlite";
import { MailboxStore, RenameError } from "../src/db.js";

function backdate(dbPath: string, name: string, minutesAgo: number): void {
  const db = new DatabaseSync(dbPath);
  const iso = new Date(Date.now() - minutesAgo * 60_000).toISOString();
  db.prepare("UPDATE mailboxes SET last_seen_at = ? WHERE name = ?").run(iso, name);
  db.close();
}

let dir: string;
let dbPath: string;

beforeEach(() => {
  dir = mkdtempSync(join(tmpdir(), "claude-mailbox-test-"));
  dbPath = join(dir, "test.db");
});

afterEach(() => {
  rmSync(dir, { recursive: true, force: true });
});

describe("schema", () => {
  it("creates fresh tables and is idempotent on re-open", () => {
    const a = new MailboxStore(dbPath);
    a.upsertMailbox("alice");
    a.close();

    const b = new MailboxStore(dbPath);
    const list = b.listMailboxes();
    expect(list.map((m) => m.name)).toEqual(["alice"]);
    b.close();
  });
});

describe("send / peek / check round-trip", () => {
  it("delivers a message exactly once", () => {
    const store = new MailboxStore(dbPath);
    try {
      const result = store.send("alice", "bob", "hello bob");
      expect(result.id).toBeGreaterThan(0);

      const peek1 = store.peek("bob");
      expect(peek1.pending).toBe(1);
      expect(peek1.oldestAt).toBeInstanceOf(Date);

      const pulled = store.checkInbox("bob");
      expect(pulled).toHaveLength(1);
      expect(pulled[0]!.from_mailbox).toBe("alice");
      expect(pulled[0]!.body).toBe("hello bob");

      const peek2 = store.peek("bob");
      expect(peek2.pending).toBe(0);
      expect(peek2.oldestAt).toBeNull();

      const empty = store.checkInbox("bob");
      expect(empty).toEqual([]);
    } finally {
      store.close();
    }
  });

  it("checkInbox returns all pending in order and marks them delivered atomically", () => {
    const store = new MailboxStore(dbPath);
    try {
      for (let i = 0; i < 10; i++) {
        store.send("alice", "bob", `msg ${i}`);
      }
      const first = store.checkInbox("bob");
      expect(first).toHaveLength(10);
      expect(first.map((m) => m.body)).toEqual(
        Array.from({ length: 10 }, (_, i) => `msg ${i}`),
      );
      const second = store.checkInbox("bob");
      expect(second).toEqual([]);
    } finally {
      store.close();
    }
  });
});

describe("rename", () => {
  it("renames a mailbox and transfers undelivered messages", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("alice", "bob-old", "hi");
      store.send("alice", "bob-old", "again");

      const r = store.rename("bob-old", "bob-new");
      expect(r.from).toBe("bob-old");
      expect(r.to).toBe("bob-new");
      expect(r.messagesTransferred).toBe(2);

      // Old name is gone.
      const list = store.listMailboxes().map((m) => m.name);
      expect(list).toContain("bob-new");
      expect(list).not.toContain("bob-old");

      // Messages still pending under the new name.
      const peek = store.peek("bob-new");
      expect(peek.pending).toBe(2);

      // checkInbox under the new name yields the original bodies and the original from.
      const pulled = store.checkInbox("bob-new");
      expect(pulled.map((m) => m.body)).toEqual(["hi", "again"]);
    } finally {
      store.close();
    }
  });

  it("also rewrites the from-side when the renamed mailbox was a sender", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("sender-old", "bob", "msg-1");
      store.rename("sender-old", "sender-new");
      const pulled = store.checkInbox("bob");
      expect(pulled).toHaveLength(1);
      expect(pulled[0]!.from_mailbox).toBe("sender-new");
    } finally {
      store.close();
    }
  });

  it("treats rename-to-same-name as a no-op touch", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.upsertMailbox("alice");
      const r = store.rename("alice", "alice");
      expect(r.messagesTransferred).toBe(0);
      expect(store.listMailboxes().map((m) => m.name)).toEqual(["alice"]);
    } finally {
      store.close();
    }
  });

  it("rejects when target already exists", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.upsertMailbox("alice");
      store.upsertMailbox("bob");
      expect(() => store.rename("alice", "bob")).toThrow(RenameError);
      try {
        store.rename("alice", "bob");
      } catch (e) {
        expect((e as RenameError).reason).toBe("target-exists");
      }
      // Source still present after the failed attempt.
      expect(store.listMailboxes().map((m) => m.name)).toEqual(["alice", "bob"]);
    } finally {
      store.close();
    }
  });

  it("rejects when source is missing", () => {
    const store = new MailboxStore(dbPath);
    try {
      try {
        store.rename("nope", "fresh");
      } catch (e) {
        expect(e).toBeInstanceOf(RenameError);
        expect((e as RenameError).reason).toBe("source-missing");
      }
    } finally {
      store.close();
    }
  });
});

describe("listMailboxes", () => {
  it("returns mailboxes alphabetically with pendingForYou for the caller", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("alice", "bob", "x");
      store.send("alice", "bob", "y");
      store.send("carol", "bob", "z");

      const fromBob = store.listMailboxes("bob");
      expect(fromBob.map((m) => m.name)).toEqual(["alice", "bob", "carol"]);
      const bobRow = fromBob.find((m) => m.name === "bob");
      expect(bobRow?.pendingForYou).toBe(3);
    } finally {
      store.close();
    }
  });

  it("hides mailboxes older than hideAfterMinutes when filter is active", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.upsertMailbox("recent");
      store.upsertMailbox("stale");
      store.close();
      backdate(dbPath, "stale", 90);

      const store2 = new MailboxStore(dbPath);
      try {
        const filtered = store2.listMailboxes(undefined, { hideAfterMinutes: 60 });
        expect(filtered.map((m) => m.name)).toEqual(["recent"]);
        const unfiltered = store2.listMailboxes();
        expect(unfiltered.map((m) => m.name).sort()).toEqual(["recent", "stale"]);
      } finally {
        store2.close();
      }
    } catch (e) {
      store.close();
      throw e;
    }
  });

  it("always includes the caller and senders with pending messages, even if stale", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("stale-sender", "me", "you have mail");
      store.upsertMailbox("recent-other");
      store.upsertMailbox("stale-other");
      store.close();
      backdate(dbPath, "stale-sender", 120);
      backdate(dbPath, "stale-other", 120);
      backdate(dbPath, "me", 120);

      const store2 = new MailboxStore(dbPath);
      try {
        const filtered = store2.listMailboxes("me", { hideAfterMinutes: 60 });
        const names = filtered.map((m) => m.name).sort();
        expect(names).toContain("me");
        expect(names).toContain("stale-sender");
        expect(names).toContain("recent-other");
        expect(names).not.toContain("stale-other");
      } finally {
        store2.close();
      }
    } catch (e) {
      store.close();
      throw e;
    }
  });
});

describe("pruneStale", () => {
  it("deletes idle mailboxes with no pending messages and wipes their delivered history", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("alice", "bob", "old");
      store.checkInbox("bob");
      store.upsertMailbox("fresh");
      store.close();
      backdate(dbPath, "alice", 60 * 24 * 8);
      backdate(dbPath, "bob", 60 * 24 * 8);

      const store2 = new MailboxStore(dbPath);
      try {
        const r = store2.pruneStale(60 * 24 * 7);
        expect(r.deletedMailboxes).toBe(2);
        expect(r.deletedMessages).toBe(1);
        const remaining = store2.listMailboxes().map((m) => m.name);
        expect(remaining).toEqual(["fresh"]);
      } finally {
        store2.close();
      }
    } catch (e) {
      store.close();
      throw e;
    }
  });

  it("never deletes a mailbox that still has pending messages, even if idle", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.send("alice", "bob", "still pending");
      store.close();
      backdate(dbPath, "alice", 60 * 24 * 30);
      backdate(dbPath, "bob", 60 * 24 * 30);

      const store2 = new MailboxStore(dbPath);
      try {
        const r = store2.pruneStale(60 * 24 * 7);
        expect(r.deletedMailboxes).toBe(0);
        expect(r.deletedMessages).toBe(0);
        expect(store2.peek("bob").pending).toBe(1);
      } finally {
        store2.close();
      }
    } catch (e) {
      store.close();
      throw e;
    }
  });

  it("returns zero when deleteAfterMinutes is 0 (disabled)", () => {
    const store = new MailboxStore(dbPath);
    try {
      store.upsertMailbox("x");
      store.close();
      backdate(dbPath, "x", 60 * 24 * 365);

      const store2 = new MailboxStore(dbPath);
      try {
        const r = store2.pruneStale(0);
        expect(r).toEqual({ deletedMailboxes: 0, deletedMessages: 0 });
        expect(store2.listMailboxes().map((m) => m.name)).toEqual(["x"]);
      } finally {
        store2.close();
      }
    } catch (e) {
      store.close();
      throw e;
    }
  });
});