import { describe, it, expect } from "vitest";
import { mkdtempSync, readFileSync, rmSync, writeFileSync, mkdirSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { execFileSync } from "node:child_process";
import {
  applyInstall,
  applyUninstall,
  buildHookCommand,
  deriveProjectName,
  deriveSessionName,
  formatActivePeerList,
  formatMessagesForHook,
  parseHookStdin,
  readSettings,
  sanitizeProjectName,
  shortSessionId,
  writeSettings,
  type PeerEntry,
} from "../src/hook.js";

describe("formatMessagesForHook", () => {
  it("returns empty string for empty inbox", () => {
    expect(formatMessagesForHook("bob", [])).toBe("");
  });

  it("formats a single message", () => {
    const out = formatMessagesForHook("bob", [
      { id: 1, from: "alice", body: "hi bob", sentAt: "2026-05-19T10:00:00.000Z" },
    ]);
    expect(out).toContain("1 new mailbox message");
    expect(out).toContain("[#1] from alice (2026-05-19T10:00:00.000Z):");
    expect(out).toContain("  hi bob");
  });

  it("formats multiple messages with plural header", () => {
    const out = formatMessagesForHook("bob", [
      { id: 1, from: "alice", body: "one", sentAt: "2026-05-19T10:00:00.000Z" },
      { id: 2, from: "carol", body: "two", sentAt: "2026-05-19T10:01:00.000Z" },
    ]);
    expect(out).toContain("2 new mailbox messages");
    expect(out).toContain("[#1] from alice");
    expect(out).toContain("[#2] from carol");
  });

  it("preserves multi-line bodies with indentation", () => {
    const out = formatMessagesForHook("bob", [
      { id: 1, from: "alice", body: "line1\nline2", sentAt: "2026-05-19T10:00:00.000Z" },
    ]);
    expect(out).toContain("  line1");
    expect(out).toContain("  line2");
  });
});

describe("buildHookCommand", () => {
  it("builds a basic command", () => {
    expect(buildHookCommand("alice")).toBe("claude-mailbox check --name alice --hook");
  });

  it("appends --url when provided", () => {
    expect(buildHookCommand("alice", "http://127.0.0.1:9000")).toBe(
      "claude-mailbox check --name alice --hook --url http://127.0.0.1:9000",
    );
  });

  it("quotes names with spaces", () => {
    const cmd = buildHookCommand("my mailbox");
    expect(cmd).toContain('--name "my mailbox"');
  });
});

describe("applyInstall", () => {
  it("creates hooks structure from empty settings", () => {
    const s: Record<string, unknown> = {};
    const r = applyInstall(s, "claude-mailbox check --name bob --hook");
    expect(r).toEqual({ changed: true, reason: "added" });
    expect(s).toMatchObject({
      hooks: {
        UserPromptSubmit: [
          {
            matcher: "",
            hooks: [{ type: "command", command: "claude-mailbox check --name bob --hook" }],
          },
        ],
      },
    });
  });

  it("is idempotent — does not duplicate the same command", () => {
    const s: Record<string, unknown> = {};
    applyInstall(s, "claude-mailbox check --name bob --hook");
    const r = applyInstall(s, "claude-mailbox check --name bob --hook");
    expect(r).toEqual({ changed: false, reason: "already-present" });
    const groups = (s.hooks as { UserPromptSubmit: { hooks: unknown[] }[] }).UserPromptSubmit;
    expect(groups[0]!.hooks).toHaveLength(1);
  });

  it("preserves existing unrelated hooks", () => {
    const s: Record<string, unknown> = {
      hooks: {
        UserPromptSubmit: [
          {
            matcher: "",
            hooks: [{ type: "command", command: "echo something-else" }],
          },
        ],
        PostToolUse: [{ matcher: "Bash", hooks: [{ type: "command", command: "logger" }] }],
      },
    };
    applyInstall(s, "claude-mailbox check --name bob --hook");
    const hooks = s.hooks as { UserPromptSubmit: { hooks: { command: string }[] }[] };
    expect(hooks.UserPromptSubmit[0]!.hooks).toHaveLength(2);
    expect(hooks.UserPromptSubmit[0]!.hooks[0]!.command).toBe("echo something-else");
    expect(hooks.UserPromptSubmit[0]!.hooks[1]!.command).toBe(
      "claude-mailbox check --name bob --hook",
    );
    expect((s.hooks as Record<string, unknown>).PostToolUse).toBeDefined();
  });

  it("adds a new empty-matcher group when only non-empty matchers exist", () => {
    const s: Record<string, unknown> = {
      hooks: {
        UserPromptSubmit: [
          { matcher: "Bash", hooks: [{ type: "command", command: "echo bash-only" }] },
        ],
      },
    };
    applyInstall(s, "claude-mailbox check --name bob --hook");
    const groups = (s.hooks as { UserPromptSubmit: { matcher?: string }[] }).UserPromptSubmit;
    expect(groups).toHaveLength(2);
    expect(groups[1]!.matcher).toBe("");
  });
});

describe("applyUninstall", () => {
  it("removes the hook and cleans up empty structures", () => {
    const s: Record<string, unknown> = {};
    applyInstall(s, "claude-mailbox check --name bob --hook");
    const r = applyUninstall(s);
    expect(r).toEqual({ changed: true, reason: "removed" });
    expect(s.hooks).toBeUndefined();
  });

  it("preserves unrelated hooks in the same group", () => {
    const s: Record<string, unknown> = {
      hooks: {
        UserPromptSubmit: [
          {
            matcher: "",
            hooks: [
              { type: "command", command: "echo something-else" },
              { type: "command", command: "claude-mailbox check --name bob --hook" },
            ],
          },
        ],
      },
    };
    applyUninstall(s);
    const hooks = s.hooks as { UserPromptSubmit: { hooks: { command: string }[] }[] };
    expect(hooks.UserPromptSubmit[0]!.hooks).toHaveLength(1);
    expect(hooks.UserPromptSubmit[0]!.hooks[0]!.command).toBe("echo something-else");
  });

  it("returns not-present when there is nothing to remove", () => {
    const s: Record<string, unknown> = {
      hooks: { UserPromptSubmit: [{ matcher: "", hooks: [{ type: "command", command: "x" }] }] },
    };
    const r = applyUninstall(s);
    expect(r).toEqual({ changed: false, reason: "not-present" });
  });

  it("removes hooks installed with --url arg", () => {
    const s: Record<string, unknown> = {};
    applyInstall(s, "claude-mailbox check --name bob --hook --url http://x");
    applyUninstall(s);
    expect(s.hooks).toBeUndefined();
  });
});

describe("parseHookStdin", () => {
  it("returns null for empty or whitespace input", () => {
    expect(parseHookStdin(null)).toBeNull();
    expect(parseHookStdin("")).toBeNull();
    expect(parseHookStdin("   \n  ")).toBeNull();
  });

  it("returns null for non-JSON input", () => {
    expect(parseHookStdin("not json")).toBeNull();
    expect(parseHookStdin("{")).toBeNull();
  });

  it("returns null for JSON primitives (only objects allowed)", () => {
    expect(parseHookStdin("42")).toBeNull();
    expect(parseHookStdin("\"foo\"")).toBeNull();
    expect(parseHookStdin("null")).toBeNull();
  });

  it("parses a hook payload", () => {
    const out = parseHookStdin(
      JSON.stringify({
        session_id: "abc12345-de67-89f0-1234-567890abcdef",
        hook_event_name: "UserPromptSubmit",
        prompt: "hi",
      }),
    );
    expect(out?.session_id).toBe("abc12345-de67-89f0-1234-567890abcdef");
    expect(out?.hook_event_name).toBe("UserPromptSubmit");
  });
});

describe("shortSessionId", () => {
  it("takes first 8 hex chars from a UUID", () => {
    expect(shortSessionId("abc12345-de67-89f0-1234-567890abcdef")).toBe("abc12345");
  });

  it("normalizes case and ignores hyphens", () => {
    expect(shortSessionId("ABC12345-DE67-89F0-1234-567890ABCDEF")).toBe("abc12345");
  });

  it("falls back to a sanitized prefix for non-hex ids", () => {
    expect(shortSessionId("session-Test123")).toBe("sessiont");
  });
});

describe("sanitizeProjectName", () => {
  it("lowercases and replaces non-alnum with dashes", () => {
    expect(sanitizeProjectName("My Project!")).toBe("my-project");
  });

  it("collapses runs of separators", () => {
    expect(sanitizeProjectName("foo  __ bar")).toBe("foo-bar");
  });

  it("trims leading/trailing dashes", () => {
    expect(sanitizeProjectName("--foo--")).toBe("foo");
  });

  it("returns empty for purely non-alnum input", () => {
    expect(sanitizeProjectName("---")).toBe("");
    expect(sanitizeProjectName("")).toBe("");
    expect(sanitizeProjectName(null)).toBe("");
    expect(sanitizeProjectName(undefined)).toBe("");
  });

  it("caps long names", () => {
    const out = sanitizeProjectName("a".repeat(120));
    expect(out.length).toBeLessThanOrEqual(40);
  });
});

describe("deriveProjectName", () => {
  it("uses cwd basename when not in a git repo", () => {
    // tmpdir is virtually never inside a git repo; basename is platform-dependent.
    const got = deriveProjectName(tmpdir());
    expect(got).toMatch(/^[a-z0-9-]+$/);
  });

  it("falls back to 'claude' when cwd is empty", () => {
    expect(deriveProjectName("")).toBe("claude");
    expect(deriveProjectName(null)).toBe("claude");
    expect(deriveProjectName(undefined)).toBe("claude");
  });

  it("uses git toplevel basename when called from inside a repo", () => {
    // The test harness itself runs inside the claude-mailbox checkout.
    let inRepo = false;
    try {
      execFileSync("git", ["rev-parse", "--show-toplevel"], { encoding: "utf8", stdio: "pipe" });
      inRepo = true;
    } catch {
      inRepo = false;
    }
    if (!inRepo) return; // CI without git in PATH — skip.
    const got = deriveProjectName(process.cwd());
    // Anywhere in the repo, we should resolve to the repo's basename — sanitized.
    expect(got).toMatch(/^[a-z0-9-]+$/);
    expect(got.length).toBeGreaterThan(0);
  });
});

describe("deriveSessionName", () => {
  it("composes <project>-<short>", () => {
    const got = deriveSessionName("abc12345-de67-89f0-1234-567890abcdef", "");
    expect(got).toBe("claude-abc12345");
  });

  it("derives different names for different sessions in the same project", () => {
    const a = deriveSessionName("aaaa1111-de67-89f0-1234-567890abcdef", "");
    const b = deriveSessionName("bbbb2222-de67-89f0-1234-567890abcdef", "");
    expect(a).not.toBe(b);
  });
});

describe("formatActivePeerList", () => {
  const NOW = new Date("2026-05-19T12:00:00.000Z").getTime();

  const peer = (name: string, isoOffsetMinutes: number): PeerEntry => ({
    name,
    lastSeenAt: new Date(NOW - isoOffsetMinutes * 60_000).toISOString(),
  });

  it("excludes self from the list", () => {
    const out = formatActivePeerList(
      [peer("self", 1), peer("alice", 1)],
      "self",
      { windowMinutes: 60, maxPeers: 10, now: NOW },
    );
    const joined = out.join("\n");
    expect(joined).not.toContain("self");
    expect(joined).toContain("alice");
  });

  it("filters out peers older than the window", () => {
    const out = formatActivePeerList(
      [peer("recent", 5), peer("stale", 120)],
      "self",
      { windowMinutes: 60, maxPeers: 10, now: NOW },
    );
    const joined = out.join("\n");
    expect(joined).toContain("recent");
    expect(joined).not.toContain("stale");
    expect(out[0]).toContain("1 of 2 total");
  });

  it("returns a no-peers message when nothing is active", () => {
    const out = formatActivePeerList(
      [peer("ancient", 9999)],
      "self",
      { windowMinutes: 60, maxPeers: 10, now: NOW },
    );
    expect(out).toHaveLength(1);
    expect(out[0]).toMatch(/No other mailboxes seen within the last 60 minutes/);
    expect(out[0]).toContain("1 total registered");
  });

  it("caps at maxPeers and sorts most-recent first", () => {
    const out = formatActivePeerList(
      [peer("p1", 30), peer("p2", 20), peer("p3", 10)],
      "self",
      { windowMinutes: 60, maxPeers: 2, now: NOW },
    );
    const joined = out.join("\n");
    expect(joined).toContain("p3");
    expect(joined).toContain("p2");
    expect(joined).not.toContain("p1");
    expect(out[0]).toContain("2 of 3 total");
    expect(joined.indexOf("p3")).toBeLessThan(joined.indexOf("p2"));
  });

  it("ignores peers with invalid lastSeenAt", () => {
    const out = formatActivePeerList(
      [{ name: "garbage", lastSeenAt: "not-a-date" }, peer("ok", 5)],
      "self",
      { windowMinutes: 60, maxPeers: 10, now: NOW },
    );
    const joined = out.join("\n");
    expect(joined).toContain("ok");
    expect(joined).not.toContain("garbage");
  });
});

describe("readSettings / writeSettings roundtrip", () => {
  it("survives an install → write → read cycle", () => {
    const dir = mkdtempSync(join(tmpdir(), "claude-mailbox-hook-"));
    try {
      const path = join(dir, "settings.json");
      const s = readSettings(path);
      expect(s).toEqual({});
      applyInstall(s, "claude-mailbox check --name bob --hook");
      writeSettings(path, s);
      const reloaded = readSettings(path);
      expect(reloaded.hooks?.UserPromptSubmit?.[0]?.hooks[0]?.command).toBe(
        "claude-mailbox check --name bob --hook",
      );
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });

  it("creates parent .claude directory when missing", () => {
    const dir = mkdtempSync(join(tmpdir(), "claude-mailbox-hook-"));
    try {
      const path = join(dir, "nested", ".claude", "settings.json");
      writeSettings(path, { hooks: {} });
      expect(readFileSync(path, "utf8")).toContain('"hooks"');
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });

  it("preserves non-hook settings keys", () => {
    const dir = mkdtempSync(join(tmpdir(), "claude-mailbox-hook-"));
    try {
      const path = join(dir, "settings.json");
      mkdirSync(dir, { recursive: true });
      writeFileSync(
        path,
        JSON.stringify({ model: "sonnet", permissions: { allow: ["Bash"] } }, null, 2),
      );
      const s = readSettings(path);
      applyInstall(s, "claude-mailbox check --name bob --hook");
      writeSettings(path, s);
      const reloaded = readSettings(path) as {
        model?: string;
        permissions?: { allow?: string[] };
        hooks?: unknown;
      };
      expect(reloaded.model).toBe("sonnet");
      expect(reloaded.permissions?.allow).toEqual(["Bash"]);
      expect(reloaded.hooks).toBeDefined();
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  });
});