/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import {
  SessionSelector,
  extractFirstUserMessage,
  formatRelativeTime,
  SessionError,
  convertSessionToHistoryFormats,
} from './sessionUtils.js';
import {
  SESSION_FILE_PREFIX,
  type Storage,
  type MessageRecord,
  CoreToolCallStatus,
} from '@google/gemini-cli-core';
import * as fs from 'node:fs/promises';
import path from 'node:path';
import { randomUUID } from 'node:crypto';

describe('SessionSelector', () => {
  let tmpDir: string;
  let storage: Storage;

  beforeEach(async () => {
    // Create a temporary directory for testing
    tmpDir = path.join(process.cwd(), '.tmp-test-sessions');
    await fs.mkdir(tmpDir, { recursive: true });

    // Mock storage
    storage = {
      getProjectTempDir: () => tmpDir,
    } as Partial<Storage> as Storage;
  });

  afterEach(async () => {
    // Clean up test files
    try {
      await fs.rm(tmpDir, { recursive: true, force: true });
    } catch {
      // Ignore cleanup errors
    }
  });

  describe('sessionExists', () => {
    it('should return true if a session file with the exact UUID exists', async () => {
      const sessionId = randomUUID();
      const chatsDir = path.join(tmpDir, 'chats');
      await fs.mkdir(chatsDir, { recursive: true });
      await fs.writeFile(
        path.join(
          chatsDir,
          `session-20240101T000000-${sessionId.slice(0, 8)}.jsonl`,
        ),
        JSON.stringify({ sessionId }),
      );

      const selector = new SessionSelector(storage);
      const exists = await selector.sessionExists(sessionId);
      expect(exists).toBe(true);
    });

    it('should return false if no session file matches the UUID', async () => {
      const sessionId = randomUUID();
      const chatsDir = path.join(tmpDir, 'chats');
      await fs.mkdir(chatsDir, { recursive: true });
      await fs.writeFile(
        path.join(chatsDir, `session-different-uuid-20240101.jsonl`),
        '{}',
      );

      const selector = new SessionSelector(storage);
      const exists = await selector.sessionExists(sessionId);
      expect(exists).toBe(false);
    });

    it('should return false if the chats directory does not exist', async () => {
      const sessionId = randomUUID();
      // Notice we do NOT create chatsDir here.
      const selector = new SessionSelector(storage);
      const exists = await selector.sessionExists(sessionId);
      expect(exists).toBe(false);
    });
  });

  it('should resolve session by UUID', async () => {
    const sessionId1 = randomUUID();
    const sessionId2 = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session1 = {
      sessionId: sessionId1,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Test message 1',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const session2 = {
      sessionId: sessionId2,
      projectHash: 'test-hash',
      startTime: '2024-01-01T11:00:00.000Z',
      lastUpdated: '2024-01-01T11:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Test message 2',
          id: 'msg2',
          timestamp: '2024-01-01T11:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId1.slice(0, 8)}.json`,
      ),
      JSON.stringify(session1, null, 2),
    );

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${sessionId2.slice(0, 8)}.json`,
      ),
      JSON.stringify(session2, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    // Test resolving by UUID
    const result1 = await sessionSelector.resolveSession(sessionId1);
    expect(result1.sessionData.sessionId).toBe(sessionId1);
    expect(result1.sessionData.messages[0].content).toBe('Test message 1');

    const result2 = await sessionSelector.resolveSession(sessionId2);
    expect(result2.sessionData.sessionId).toBe(sessionId2);
    expect(result2.sessionData.messages[0].content).toBe('Test message 2');
  });

  it('should resolve session by index', async () => {
    const sessionId1 = randomUUID();
    const sessionId2 = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session1 = {
      sessionId: sessionId1,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'First session',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const session2 = {
      sessionId: sessionId2,
      projectHash: 'test-hash',
      startTime: '2024-01-01T11:00:00.000Z',
      lastUpdated: '2024-01-01T11:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Second session',
          id: 'msg2',
          timestamp: '2024-01-01T11:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId1.slice(0, 8)}.json`,
      ),
      JSON.stringify(session1, null, 2),
    );

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${sessionId2.slice(0, 8)}.json`,
      ),
      JSON.stringify(session2, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    // Test resolving by index (1-based)
    const result1 = await sessionSelector.resolveSession('1');
    expect(result1.sessionData.messages[0].content).toBe('First session');

    const result2 = await sessionSelector.resolveSession('2');
    expect(result2.sessionData.messages[0].content).toBe('Second session');
  });

  it('should resolve latest session', async () => {
    const sessionId1 = randomUUID();
    const sessionId2 = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session1 = {
      sessionId: sessionId1,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'First session',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const session2 = {
      sessionId: sessionId2,
      projectHash: 'test-hash',
      startTime: '2024-01-01T11:00:00.000Z',
      lastUpdated: '2024-01-01T11:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Latest session',
          id: 'msg2',
          timestamp: '2024-01-01T11:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId1.slice(0, 8)}.json`,
      ),
      JSON.stringify(session1, null, 2),
    );

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${sessionId2.slice(0, 8)}.json`,
      ),
      JSON.stringify(session2, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    // Test resolving latest
    const result = await sessionSelector.resolveSession('latest');
    expect(result.sessionData.messages[0].content).toBe('Latest session');
  });

  it('should resolve session by UUID with whitespace (trimming)', async () => {
    const sessionId = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session = {
      sessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Test message',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(session, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    // Test resolving by UUID with leading/trailing spaces
    const result = await sessionSelector.resolveSession(`  ${sessionId}  `);
    expect(result.sessionData.sessionId).toBe(sessionId);
    expect(result.sessionData.messages[0].content).toBe('Test message');
  });

  it('should deduplicate sessions by ID', async () => {
    const sessionId = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const sessionOriginal = {
      sessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Original',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const sessionDuplicate = {
      sessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T11:00:00.000Z', // Newer
      messages: [
        {
          type: 'user',
          content: 'Newer Duplicate',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    // File 1
    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(sessionOriginal, null, 2),
    );

    // File 2 (Simulate a copy or newer version with same ID)
    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${sessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(sessionDuplicate, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    expect(sessions.length).toBe(1);
    expect(sessions[0].id).toBe(sessionId);
    // Should keep the one with later lastUpdated
    expect(sessions[0].lastUpdated).toBe('2024-01-01T11:00:00.000Z');
  });

  it('should throw error for invalid session identifier', async () => {
    const sessionId1 = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session1 = {
      sessionId: sessionId1,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Test message 1',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId1.slice(0, 8)}.json`,
      ),
      JSON.stringify(session1, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    await expect(
      sessionSelector.resolveSession('invalid-uuid'),
    ).rejects.toThrow(SessionError);

    await expect(sessionSelector.resolveSession('999')).rejects.toThrow(
      SessionError,
    );
  });

  it('should throw SessionError with NO_SESSIONS_FOUND when resolving latest with no sessions', async () => {
    // Empty chats directory — no session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const emptyStorage = {
      getProjectTempDir: () => tmpDir,
    } as Partial<Storage> as Storage;

    const sessionSelector = new SessionSelector(emptyStorage);

    await expect(sessionSelector.resolveSession('latest')).rejects.toSatisfy(
      (error) => {
        expect(error).toBeInstanceOf(SessionError);
        expect((error as SessionError).code).toBe('NO_SESSIONS_FOUND');
        return true;
      },
    );
  });

  it('should not list sessions with only system messages', async () => {
    const sessionIdWithUser = randomUUID();
    const sessionIdSystemOnly = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    // Session with user message - should be listed
    const sessionWithUser = {
      sessionId: sessionIdWithUser,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Hello world',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    // Session with only system messages - should NOT be listed
    const sessionSystemOnly = {
      sessionId: sessionIdSystemOnly,
      projectHash: 'test-hash',
      startTime: '2024-01-01T11:00:00.000Z',
      lastUpdated: '2024-01-01T11:30:00.000Z',
      messages: [
        {
          type: 'info',
          content: 'Session started',
          id: 'msg1',
          timestamp: '2024-01-01T11:00:00.000Z',
        },
        {
          type: 'error',
          content: 'An error occurred',
          id: 'msg2',
          timestamp: '2024-01-01T11:01:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionIdWithUser.slice(0, 8)}.json`,
      ),
      JSON.stringify(sessionWithUser, null, 2),
    );

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${sessionIdSystemOnly.slice(0, 8)}.json`,
      ),
      JSON.stringify(sessionSystemOnly, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    // Should only list the session with user message
    expect(sessions.length).toBe(1);
    expect(sessions[0].id).toBe(sessionIdWithUser);
  });

  it('should not list command-only sessions', async () => {
    const commandOnlySessionId = randomUUID();

    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const metadata = {
      sessionId: commandOnlySessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:01:00.000Z',
    };
    const commandMessage = {
      type: 'user',
      content: '/resume',
      id: 'msg1',
      timestamp: '2024-01-01T10:00:30.000Z',
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${commandOnlySessionId.slice(0, 8)}.jsonl`,
      ),
      `${JSON.stringify(metadata)}\n${JSON.stringify(commandMessage)}\n`,
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

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

  it('should use the first non-command user message for display', async () => {
    const sessionId = randomUUID();

    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const metadata = {
      sessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:02:00.000Z',
    };
    const commandMessage = {
      type: 'user',
      content: '/resume',
      id: 'msg1',
      timestamp: '2024-01-01T10:00:30.000Z',
    };
    const realMessage = {
      type: 'user',
      content: 'Help me fix resume history',
      id: 'msg2',
      timestamp: '2024-01-01T10:01:00.000Z',
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.jsonl`,
      ),
      `${JSON.stringify(metadata)}\n${JSON.stringify(commandMessage)}\n${JSON.stringify(realMessage)}\n`,
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    expect(sessions).toHaveLength(1);
    expect(sessions[0].firstUserMessage).toBe('Help me fix resume history');
    expect(sessions[0].displayName).toBe('Help me fix resume history');
  });

  it('should list session with gemini message even without user message', async () => {
    const sessionIdGeminiOnly = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    // Session with only gemini message - should be listed
    const sessionGeminiOnly = {
      sessionId: sessionIdGeminiOnly,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'gemini',
          content: 'Hello, how can I help?',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionIdGeminiOnly.slice(0, 8)}.json`,
      ),
      JSON.stringify(sessionGeminiOnly, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    // Should list the session with gemini message
    expect(sessions.length).toBe(1);
    expect(sessions[0].id).toBe(sessionIdGeminiOnly);
  });

  it('should not list sessions marked as subagent', async () => {
    const mainSessionId = randomUUID();
    const subagentSessionId = randomUUID();

    // Create test session files
    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    // Main session - should be listed
    const mainSession = {
      sessionId: mainSessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Hello world',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
      kind: 'main',
    };

    // Subagent session - should NOT be listed
    const subagentSession = {
      sessionId: subagentSessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T11:00:00.000Z',
      lastUpdated: '2024-01-01T11:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Internal subagent task',
          id: 'msg1',
          timestamp: '2024-01-01T11:00:00.000Z',
        },
      ],
      kind: 'subagent',
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${mainSessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(mainSession, null, 2),
    );

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T11-00-${subagentSessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(subagentSession, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    // Should only list the main session
    expect(sessions.length).toBe(1);
    expect(sessions[0].id).toBe(mainSessionId);
  });

  it('should list legacy session JSON without timestamps (regression #18593)', async () => {
    const sessionId = randomUUID();

    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session = {
      sessionId,
      projectHash: 'test-hash',
      messages: [
        {
          type: 'user',
          content: 'Legacy session message',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const filePath = path.join(
      chatsDir,
      `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.json`,
    );
    await fs.writeFile(filePath, JSON.stringify(session, null, 2));
    const fallbackTimestamp = new Date('2024-01-01T10:30:00.000Z');
    await fs.utimes(filePath, fallbackTimestamp, fallbackTimestamp);

    const sessionSelector = new SessionSelector(storage);
    const sessions = await sessionSelector.listSessions();

    expect(sessions.length).toBe(1);
    expect(sessions[0].id).toBe(sessionId);
    expect(sessions[0].startTime).toBe(fallbackTimestamp.toISOString());
    expect(sessions[0].lastUpdated).toBe(fallbackTimestamp.toISOString());
  });

  it('should resolve legacy session JSON without timestamps by UUID (regression #18593)', async () => {
    const sessionId = randomUUID();

    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session = {
      sessionId,
      projectHash: 'test-hash',
      messages: [
        {
          type: 'user',
          content: 'Legacy session message',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    const filePath = path.join(
      chatsDir,
      `${SESSION_FILE_PREFIX}2024-01-01T10-00-${sessionId.slice(0, 8)}.json`,
    );
    await fs.writeFile(filePath, JSON.stringify(session, null, 2));
    const fallbackTimestamp = new Date('2024-01-01T10:30:00.000Z');
    await fs.utimes(filePath, fallbackTimestamp, fallbackTimestamp);

    const sessionSelector = new SessionSelector(storage);
    const result = await sessionSelector.resolveSession(sessionId);

    expect(result.sessionData.sessionId).toBe(sessionId);
    expect(result.sessionData.startTime).toBe(fallbackTimestamp.toISOString());
    expect(result.sessionData.lastUpdated).toBe(
      fallbackTimestamp.toISOString(),
    );
  });

  it('should throw INVALID_SESSION_IDENTIFIER for a UUID that does not exist on disk at all', async () => {
    const existingSessionId = randomUUID();
    const nonExistentId = randomUUID();

    const chatsDir = path.join(tmpDir, 'chats');
    await fs.mkdir(chatsDir, { recursive: true });

    const session = {
      sessionId: existingSessionId,
      projectHash: 'test-hash',
      startTime: '2024-01-01T10:00:00.000Z',
      lastUpdated: '2024-01-01T10:30:00.000Z',
      messages: [
        {
          type: 'user',
          content: 'Hello',
          id: 'msg1',
          timestamp: '2024-01-01T10:00:00.000Z',
        },
      ],
    };

    await fs.writeFile(
      path.join(
        chatsDir,
        `${SESSION_FILE_PREFIX}2024-01-01T10-00-${existingSessionId.slice(0, 8)}.json`,
      ),
      JSON.stringify(session, null, 2),
    );

    const sessionSelector = new SessionSelector(storage);

    await expect(sessionSelector.findSession(nonExistentId)).rejects.toSatisfy(
      (error) => {
        expect(error).toBeInstanceOf(SessionError);
        expect((error as SessionError).code).toBe('INVALID_SESSION_IDENTIFIER');
        return true;
      },
    );
  });
});

describe('extractFirstUserMessage', () => {
  it('should extract first non-resume user message', () => {
    const messages = [
      {
        type: 'user',
        content: '/resume',
        id: 'msg1',
        timestamp: '2024-01-01T10:00:00.000Z',
      },
      {
        type: 'user',
        content: 'Hello world',
        id: 'msg2',
        timestamp: '2024-01-01T10:01:00.000Z',
      },
    ] as MessageRecord[];

    expect(extractFirstUserMessage(messages)).toBe('Hello world');
  });

  it('should not truncate long messages', () => {
    const longMessage = 'a'.repeat(150);
    const messages = [
      {
        type: 'user',
        content: longMessage,
        id: 'msg1',
        timestamp: '2024-01-01T10:00:00.000Z',
      },
    ] as MessageRecord[];

    const result = extractFirstUserMessage(messages);
    expect(result).toBe(longMessage);
  });

  it('should return "Empty conversation" for no user messages', () => {
    const messages = [
      {
        type: 'gemini',
        content: 'Hello',
        id: 'msg1',
        timestamp: '2024-01-01T10:00:00.000Z',
      },
    ] as MessageRecord[];

    expect(extractFirstUserMessage(messages)).toBe('Empty conversation');
  });
});

describe('formatRelativeTime', () => {
  it('should format time correctly', () => {
    const now = new Date();

    // 5 minutes ago
    const fiveMinutesAgo = new Date(now.getTime() - 5 * 60 * 1000);
    expect(formatRelativeTime(fiveMinutesAgo.toISOString())).toBe(
      '5 minutes ago',
    );

    // 1 minute ago
    const oneMinuteAgo = new Date(now.getTime() - 1 * 60 * 1000);
    expect(formatRelativeTime(oneMinuteAgo.toISOString())).toBe('1 minute ago');

    // 2 hours ago
    const twoHoursAgo = new Date(now.getTime() - 2 * 60 * 60 * 1000);
    expect(formatRelativeTime(twoHoursAgo.toISOString())).toBe('2 hours ago');

    // 1 hour ago
    const oneHourAgo = new Date(now.getTime() - 1 * 60 * 60 * 1000);
    expect(formatRelativeTime(oneHourAgo.toISOString())).toBe('1 hour ago');

    // 3 days ago
    const threeDaysAgo = new Date(now.getTime() - 3 * 24 * 60 * 60 * 1000);
    expect(formatRelativeTime(threeDaysAgo.toISOString())).toBe('3 days ago');

    // 1 day ago
    const oneDayAgo = new Date(now.getTime() - 1 * 24 * 60 * 60 * 1000);
    expect(formatRelativeTime(oneDayAgo.toISOString())).toBe('1 day ago');

    // Just now (within 60 seconds)
    const thirtySecondsAgo = new Date(now.getTime() - 30 * 1000);
    expect(formatRelativeTime(thirtySecondsAgo.toISOString())).toBe('Just now');
  });
});

describe('convertSessionToHistoryFormats', () => {
  it('should preserve tool call arguments', () => {
    const messages: MessageRecord[] = [
      {
        id: '1',
        timestamp: new Date().toISOString(),
        type: 'gemini',
        content: '',
        toolCalls: [
          {
            id: 'call_1',
            name: 'update_topic',
            args: {
              title: 'Researching bug',
              summary: 'I am looking into the issue.',
            },
            status: CoreToolCallStatus.Success,
            timestamp: new Date().toISOString(),
            displayName: 'Update Topic Context',
            description: 'Updating the topic',
            renderOutputAsMarkdown: true,
            resultDisplay: 'Topic updated',
          },
        ],
      },
    ];

    const result = convertSessionToHistoryFormats(messages);

    expect(result.uiHistory).toHaveLength(1);
    const toolGroup = result.uiHistory[0];
    if (toolGroup.type === 'tool_group') {
      expect(toolGroup.tools).toHaveLength(1);
      const tool = toolGroup.tools[0];
      expect(tool.callId).toBe('call_1');
      expect(tool.name).toBe('Update Topic Context');
      expect(tool.description).toBe('Updating the topic');
      expect(tool.renderOutputAsMarkdown).toBe(true);
      expect(tool.status).toBe(CoreToolCallStatus.Success);
      expect(tool.resultDisplay).toBe('Topic updated');
      expect(tool.args).toEqual({
        title: 'Researching bug',
        summary: 'I am looking into the issue.',
      });
    } else {
      throw new Error('Expected tool_group history item');
    }
  });

  it('should map tool call status correctly when not success', () => {
    const messages: MessageRecord[] = [
      {
        id: '1',
        timestamp: new Date().toISOString(),
        type: 'gemini',
        content: '',
        toolCalls: [
          {
            id: 'call_1',
            name: 'test_tool',
            status: CoreToolCallStatus.Error,
            timestamp: new Date().toISOString(),
            args: {},
          },
          {
            id: 'call_2',
            name: 'test_tool_2',
            status: CoreToolCallStatus.Cancelled,
            timestamp: new Date().toISOString(),
            args: {},
          },
        ],
      },
    ];

    const result = convertSessionToHistoryFormats(messages);
    expect(result.uiHistory).toHaveLength(1);

    const toolGroup = result.uiHistory[0];
    if (toolGroup.type === 'tool_group') {
      expect(toolGroup.tools).toHaveLength(2);
      expect(toolGroup.tools[0].status).toBe(CoreToolCallStatus.Error);
      expect(toolGroup.tools[1].status).toBe(CoreToolCallStatus.Error); // Cancelled maps to error in this older format projection
    } else {
      throw new Error('Expected tool_group history item');
    }
  });

  it('should convert various message types', () => {
    const messages: MessageRecord[] = [
      {
        id: '1',
        timestamp: new Date().toISOString(),
        type: 'user',
        content: 'Hello user',
      },
      {
        id: '2',
        timestamp: new Date().toISOString(),
        type: 'info',
        content: 'System info',
      },
      {
        id: '3',
        timestamp: new Date().toISOString(),
        type: 'error',
        content: 'System error',
      },
      {
        id: '4',
        timestamp: new Date().toISOString(),
        type: 'warning',
        content: 'System warning',
      },
      {
        id: '5',
        timestamp: new Date().toISOString(),
        type: 'gemini',
        content: 'Hello gemini',
        thoughts: [
          {
            subject: 'Thinking',
            description: 'about things',
            timestamp: new Date().toISOString(),
          },
        ],
      },
    ];

    const result = convertSessionToHistoryFormats(messages);

    // thoughts become a separate item
    expect(result.uiHistory).toHaveLength(6);
    expect(result.uiHistory[0]).toEqual({ type: 'user', text: 'Hello user' });
    expect(result.uiHistory[1]).toEqual({ type: 'info', text: 'System info' });
    expect(result.uiHistory[2]).toEqual({
      type: 'error',
      text: 'System error',
    });
    expect(result.uiHistory[3]).toEqual({
      type: 'warning',
      text: 'System warning',
    });
    expect(result.uiHistory[4]).toEqual({
      type: 'thinking',
      thought: { subject: 'Thinking', description: 'about things' },
    });
    expect(result.uiHistory[5]).toEqual({
      type: 'gemini',
      text: 'Hello gemini',
    });
  });

  it('should filter out <session_context> from UI history', () => {
    const messages: MessageRecord[] = [
      {
        id: '1',
        timestamp: new Date().toISOString(),
        type: 'user',
        content:
          '<session_context>\nThis is the Gemini CLI\n</session_context>',
      },
      {
        id: '2',
        timestamp: new Date().toISOString(),
        type: 'user',
        content: 'Real message',
      },
    ];

    const result = convertSessionToHistoryFormats(messages);
    expect(result.uiHistory).toHaveLength(1);
    expect(result.uiHistory[0].text).toBe('Real message');
  });

  it('should handle missing tool descriptions and displayNames', () => {
    const messages: MessageRecord[] = [
      {
        id: '1',
        timestamp: new Date().toISOString(),
        type: 'gemini',
        content: '',
        toolCalls: [
          {
            id: 'call_1',
            name: 'test_tool',
            status: CoreToolCallStatus.Success,
            timestamp: new Date().toISOString(),
            args: {},
          },
        ],
      },
    ];

    const result = convertSessionToHistoryFormats(messages);
    expect(result.uiHistory).toHaveLength(1);

    const toolGroup = result.uiHistory[0];
    if (toolGroup.type === 'tool_group') {
      expect(toolGroup.tools[0].name).toBe('test_tool'); // Fallback to name
      expect(toolGroup.tools[0].description).toBe(''); // Fallback to empty string
    } else {
      throw new Error('Expected tool_group history item');
    }
  });
});
