import { casefy } from '../core/casefy.core';
import { CasefyService } from '../services/casefy.service';
import { CasefyOptions } from '../types/case.types';

describe('Error Handling Branches for Branch Coverage', () => {
  describe('Core function error handling branches', () => {
    it('should cover error handling branch in casefy.core.ts (line 62)', () => {
      // Test the error handling path that's hard to reach
      const options: CasefyOptions = {
        from: 'camelCase',
        to: 'snake_case',
      };

      // Test with various inputs that might cause internal errors
      const problematicInputs = [
        // Circular reference
        (() => {
          const obj: any = { test: 'value' };
          obj.self = obj;
          return obj;
        })(),
        // Very deep nesting that might cause stack overflow
        (() => {
          let deep: any = { level: 0 };
          for (let i = 1; i < 1000; i++) {
            deep = { level: i, nested: deep };
          }
          return deep;
        })(),
        // Large object that might cause memory issues
        (() => {
          const large: any = {};
          for (let i = 0; i < 10000; i++) {
            large[`key${i}`] = `value${i}`;
          }
          return large;
        })(),
      ];

      problematicInputs.forEach((input) => {
        // These should not throw errors and should return gracefully
        const result = casefy(input, options);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
        expect(result).toHaveProperty('from');
        expect(result).toHaveProperty('to');
        expect(result).toHaveProperty('deep');
        expect(result).toHaveProperty('arrays');
      });
    });

    it('should cover specific error types in core function', () => {
      const options: CasefyOptions = {
        from: 'camelCase',
        to: 'snake_case',
      };

      // Test with inputs that might cause specific error types
      const errorInputs = [
        new Error('test error'),
        new Date(),
        new RegExp('test'),
        new Map(),
        new Set(),
        Symbol('test'),
        BigInt(123),
        () => {},
        class TestClass {},
        new Array(1000000).fill('test'),
      ];

      errorInputs.forEach((input) => {
        const result = casefy(input, options);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });

  describe('Service error handling branches', () => {
    it('should cover error handling branch in casefy.service.ts (line 63)', () => {
      const service = new CasefyService('camelCase', 'snake_case');

      // Test with inputs that might cause transformation errors
      const errorInputs = [
        // Circular reference
        (() => {
          const obj: any = { test: 'value' };
          obj.self = obj;
          return obj;
        })(),
        // Very deep nesting
        (() => {
          let deep: any = { level: 0 };
          for (let i = 1; i < 100; i++) {
            deep = { level: i, nested: deep };
          }
          return deep;
        })(),
        // Large arrays
        new Array(10000).fill({ test: 'value' }),
        // Complex nested structures
        {
          level1: {
            level2: {
              level3: {
                level4: {
                  level5: {
                    test: 'deep value',
                  },
                },
              },
            },
          },
        },
      ];

      errorInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
        expect(result).toHaveProperty('fromCase');
        expect(result).toHaveProperty('toCase');
      });
    });

    it('should cover service error handling with complex options', () => {
      const service = new CasefyService('snake_case', 'camelCase', {
        deep: true,
        arrays: true,
        preserveTypes: false,
        fieldMappings: {
          user_id: 'id',
          profile_data: 'profile',
        },
        excludeFields: ['secret'],
        includeFields: ['name', 'email'],
      });

      // Test with complex inputs that might cause errors
      const complexInputs = [
        {
          user_id: 123,
          user_name: 'John',
          user_email: 'john@example.com',
          secret: 'hidden',
          profile_data: {
            first_name: 'John',
            last_name: 'Doe',
            settings: {
              theme: 'dark',
              notifications: true,
            },
          },
          tags: ['admin', 'user'],
          metadata: {
            created_at: new Date(),
            updated_at: new Date(),
            version: 1.0,
          },
        },
        [
          { user_id: 1, name: 'User 1' },
          { user_id: 2, name: 'User 2' },
          { user_id: 3, name: 'User 3' },
        ],
        {
          data: {
            users: [
              { id: 1, profile: { name: 'John' } },
              { id: 2, profile: { name: 'Jane' } },
            ],
          },
        },
      ];

      complexInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });

  describe('Type checking error branches', () => {
    it('should cover type checking branches in transformers', () => {
      const service = new CasefyService('camelCase', 'snake_case');

      // Test with various types that might cause type checking issues
      const typeInputs = [
        null,
        undefined,
        true,
        false,
        0,
        123,
        -123,
        Infinity,
        -Infinity,
        NaN,
        '',
        'string',
        [],
        {},
        new Date(),
        new RegExp('test'),
        new Map(),
        new Set(),
        Symbol('test'),
        BigInt(123),
        () => {},
        class TestClass {},
        new Error('test'),
        new Array(1000).fill('test'),
      ];

      typeInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });

  describe('Field mapping error branches', () => {
    it('should cover field mapping error branches', () => {
      const service = new CasefyService('snake_case', 'camelCase', {
        fieldMappings: {
          user_id: 'id',
          profile_data: 'profile',
          nested_field: 'nestedField',
        },
      });

      // Test with inputs that might cause field mapping errors
      const mappingInputs = [
        {
          user_id: 123,
          profile_data: {
            first_name: 'John',
            last_name: 'Doe',
          },
          nested_field: {
            deep_nested: 'value',
          },
        },
        {
          user_id: null,
          profile_data: undefined,
          nested_field: [],
        },
        {
          user_id: new Date(),
          profile_data: new RegExp('test'),
          nested_field: new Map(),
        },
      ];

      mappingInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });

  describe('Include/Exclude field error branches', () => {
    it('should cover include/exclude field error branches', () => {
      const service = new CasefyService('snake_case', 'camelCase', {
        includeFields: ['user_name', 'user_email'],
        excludeFields: ['secret', 'internal_data'],
      });

      const fieldInputs = [
        {
          user_name: 'John',
          user_email: 'john@example.com',
          secret: 'hidden',
          internal_data: 'confidential',
          other_field: 'value',
        },
        {
          user_name: null,
          user_email: undefined,
          secret: '',
          internal_data: 0,
          other_field: false,
        },
      ];

      fieldInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });

  describe('Deep transformation error branches', () => {
    it('should cover deep transformation error branches', () => {
      const service = new CasefyService('snake_case', 'camelCase', {
        deep: true,
        arrays: true,
        preserveTypes: true,
      });

      const deepInputs = [
        {
          level1: {
            level2: {
              level3: {
                level4: {
                  level5: {
                    test: 'deep value',
                  },
                },
              },
            },
          },
        },
        {
          array: [{ nested: { value: 1 } }, { nested: { value: 2 } }, { nested: { value: 3 } }],
        },
        {
          mixed: {
            primitive: 'value',
            array: [1, 2, 3],
            object: { nested: 'value' },
            null: null,
            undefined: undefined,
          },
        },
      ];

      deepInputs.forEach((input) => {
        const result = service.transform(input);
        expect(result).toHaveProperty('data');
        expect(result).toHaveProperty('transformedKeys');
      });
    });
  });
});