import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import { resolveModelString, getEffectiveModel } from '../src/resolver';
import { CLAUDE_MODEL_MAP, DEFAULT_MODELS } from '@automaker/types';

describe('model-resolver', () => {
  let consoleLogSpy: ReturnType<typeof vi.spyOn>;
  let consoleWarnSpy: ReturnType<typeof vi.spyOn>;

  beforeEach(() => {
    consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
    consoleWarnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
  });

  afterEach(() => {
    consoleLogSpy.mockRestore();
    consoleWarnSpy.mockRestore();
  });

  describe('resolveModelString', () => {
    describe('with undefined/null input', () => {
      it('should return default model when modelKey is undefined', () => {
        const result = resolveModelString(undefined);
        expect(result).toBe(DEFAULT_MODELS.claude);
      });

      it('should return custom default when modelKey is undefined', () => {
        const customDefault = 'claude-opus-4-20241113';
        const result = resolveModelString(undefined, customDefault);
        expect(result).toBe(customDefault);
      });

      it('should return default when modelKey is empty string', () => {
        const result = resolveModelString('');
        expect(result).toBe(DEFAULT_MODELS.claude);
      });
    });

    describe('with full Claude model strings', () => {
      it('should pass through full Claude model string unchanged', () => {
        const fullModel = 'claude-sonnet-4-20250514';
        const result = resolveModelString(fullModel);

        expect(result).toBe(fullModel);
        expect(consoleLogSpy).toHaveBeenCalledWith(
          expect.stringContaining('Using full Claude model string')
        );
      });

      it('should handle claude-opus model strings', () => {
        const fullModel = 'claude-opus-4-20241113';
        const result = resolveModelString(fullModel);

        expect(result).toBe(fullModel);
      });

      it('should handle claude-haiku model strings', () => {
        const fullModel = 'claude-3-5-haiku-20241022';
        const result = resolveModelString(fullModel);

        expect(result).toBe(fullModel);
      });

      it("should handle any string containing 'claude-'", () => {
        const customModel = 'claude-custom-experimental-v1';
        const result = resolveModelString(customModel);

        expect(result).toBe(customModel);
      });
    });

    describe('with model aliases', () => {
      it("should resolve 'sonnet' alias", () => {
        const result = resolveModelString('sonnet');

        expect(result).toBe(CLAUDE_MODEL_MAP.sonnet);
        expect(consoleLogSpy).toHaveBeenCalledWith(
          expect.stringContaining('Resolved model alias: "sonnet"')
        );
      });

      it("should resolve 'opus' alias", () => {
        const result = resolveModelString('opus');

        expect(result).toBe(CLAUDE_MODEL_MAP.opus);
        expect(consoleLogSpy).toHaveBeenCalledWith(
          expect.stringContaining('Resolved model alias: "opus"')
        );
      });

      it("should resolve 'haiku' alias", () => {
        const result = resolveModelString('haiku');

        expect(result).toBe(CLAUDE_MODEL_MAP.haiku);
      });

      it('should log the resolution for aliases', () => {
        resolveModelString('sonnet');

        expect(consoleLogSpy).toHaveBeenCalledWith(expect.stringContaining('Resolved model alias'));
        expect(consoleLogSpy).toHaveBeenCalledWith(
          expect.stringContaining(CLAUDE_MODEL_MAP.sonnet)
        );
      });
    });

    describe('with unknown model keys', () => {
      it('should return default for unknown model key', () => {
        const result = resolveModelString('unknown-model');

        expect(result).toBe(DEFAULT_MODELS.claude);
      });

      it('should warn about unknown model key', () => {
        resolveModelString('unknown-model');

        expect(consoleWarnSpy).toHaveBeenCalledWith(expect.stringContaining('Unknown model key'));
        expect(consoleWarnSpy).toHaveBeenCalledWith(expect.stringContaining('unknown-model'));
      });

      it('should use custom default for unknown model key', () => {
        const customDefault = 'claude-opus-4-20241113';
        const result = resolveModelString('gpt-4', customDefault);

        expect(result).toBe(customDefault);
      });

      it('should warn and show default being used', () => {
        const customDefault = 'claude-custom-default';
        resolveModelString('invalid-key', customDefault);

        expect(consoleWarnSpy).toHaveBeenCalledWith(expect.stringContaining(customDefault));
      });
    });

    describe('case sensitivity', () => {
      it('should be case-sensitive for aliases', () => {
        const resultUpper = resolveModelString('SONNET');
        const resultLower = resolveModelString('sonnet');

        // Uppercase should not resolve (falls back to default)
        expect(resultUpper).toBe(DEFAULT_MODELS.claude);
        // Lowercase should resolve
        expect(resultLower).toBe(CLAUDE_MODEL_MAP.sonnet);
      });

      it('should handle mixed case in claude- strings', () => {
        const result = resolveModelString('Claude-Sonnet-4-20250514');

        // Capital 'C' means it won't match 'claude-', falls back to default
        expect(result).toBe(DEFAULT_MODELS.claude);
      });
    });

    describe('edge cases', () => {
      it('should handle model key with whitespace', () => {
        const result = resolveModelString('  sonnet  ');

        // Will not match due to whitespace, falls back to default
        expect(result).toBe(DEFAULT_MODELS.claude);
      });

      it('should handle special characters in model key', () => {
        const result = resolveModelString('model@123');

        expect(result).toBe(DEFAULT_MODELS.claude);
      });
    });
  });

  describe('getEffectiveModel', () => {
    describe('priority handling', () => {
      it('should prioritize explicit model over all others', () => {
        const explicit = 'claude-opus-4-20241113';
        const session = 'claude-sonnet-4-20250514';
        const defaultModel = 'claude-3-5-haiku-20241022';

        const result = getEffectiveModel(explicit, session, defaultModel);

        expect(result).toBe(explicit);
      });

      it('should use session model when explicit is undefined', () => {
        const session = 'claude-sonnet-4-20250514';
        const defaultModel = 'claude-3-5-haiku-20241022';

        const result = getEffectiveModel(undefined, session, defaultModel);

        expect(result).toBe(session);
      });

      it('should use default model when both explicit and session are undefined', () => {
        const defaultModel = 'claude-opus-4-20241113';

        const result = getEffectiveModel(undefined, undefined, defaultModel);

        expect(result).toBe(defaultModel);
      });

      it('should use system default when all are undefined', () => {
        const result = getEffectiveModel(undefined, undefined, undefined);

        expect(result).toBe(DEFAULT_MODELS.claude);
      });
    });

    describe('with aliases', () => {
      it('should resolve explicit model alias', () => {
        const result = getEffectiveModel('opus', 'sonnet');

        expect(result).toBe(CLAUDE_MODEL_MAP.opus);
      });

      it('should resolve session model alias when explicit is undefined', () => {
        const result = getEffectiveModel(undefined, 'haiku');

        expect(result).toBe(CLAUDE_MODEL_MAP.haiku);
      });

      it('should prioritize explicit alias over session full string', () => {
        const result = getEffectiveModel('sonnet', 'claude-opus-4-20241113');

        expect(result).toBe(CLAUDE_MODEL_MAP.sonnet);
      });
    });

    describe('with empty strings', () => {
      it('should treat empty explicit string as undefined', () => {
        const session = 'claude-sonnet-4-20250514';

        const result = getEffectiveModel('', session);

        expect(result).toBe(session);
      });

      it('should treat empty session string as undefined', () => {
        const defaultModel = 'claude-opus-4-20241113';

        const result = getEffectiveModel(undefined, '', defaultModel);

        expect(result).toBe(defaultModel);
      });

      it('should handle all empty strings', () => {
        const result = getEffectiveModel('', '', '');

        // Empty strings are falsy, so explicit || session becomes "" || ""  = ""
        // Then resolveModelString("", "") returns "" (not in CLAUDE_MODEL_MAP, not containing "claude-")
        // This actually returns the custom default which is ""
        expect(result).toBe('');
      });
    });

    describe('integration scenarios', () => {
      it('should handle user overriding session model with alias', () => {
        const sessionModel = 'claude-sonnet-4-20250514';
        const userChoice = 'opus';

        const result = getEffectiveModel(userChoice, sessionModel);

        expect(result).toBe(CLAUDE_MODEL_MAP.opus);
      });

      it('should handle fallback chain: unknown -> session -> default', () => {
        const result = getEffectiveModel('invalid', 'also-invalid', 'claude-opus-4-20241113');

        // Both invalid models fall back to default
        expect(result).toBe('claude-opus-4-20241113');
      });

      it('should handle session with alias, no explicit', () => {
        const result = getEffectiveModel(undefined, 'haiku');

        expect(result).toBe(CLAUDE_MODEL_MAP.haiku);
      });
    });
  });

  describe('CLAUDE_MODEL_MAP integration', () => {
    it('should have valid mappings for all known aliases', () => {
      const aliases = ['sonnet', 'opus', 'haiku'];

      for (const alias of aliases) {
        const resolved = resolveModelString(alias);
        expect(resolved).toBeDefined();
        expect(resolved).toContain('claude-');
        expect(resolved).toBe(CLAUDE_MODEL_MAP[alias]);
      }
    });
  });

  describe('DEFAULT_MODELS integration', () => {
    it('should use DEFAULT_MODELS.claude as fallback', () => {
      const result = resolveModelString(undefined);

      expect(result).toBe(DEFAULT_MODELS.claude);
      expect(DEFAULT_MODELS.claude).toBeDefined();
      expect(DEFAULT_MODELS.claude).toContain('claude-');
    });
  });
});