import {jest, describe, it, expect, beforeEach, beforeAll} from '@jest/globals';
import * as yaml from 'js-yaml';
import * as fs from 'fs';
import type {
  MatchConfig,
  BaseMatchConfig
} from '../src/api/get-label-configs.js';

// Define API mock functions at module level
const getPullRequestsMock = jest.fn<any>();
const getLabelConfigsMock = jest.fn<any>();
const addLabelsMock = jest.fn<any>();
const removeLabelsMock = jest.fn<any>();
const getChangedFilesMock = jest.fn<any>();
const getContentMock = jest.fn<any>();

jest.unstable_mockModule('@actions/core', () => ({
  getInput: jest.fn(),
  getMultilineInput: jest.fn(),
  getBooleanInput: jest.fn(),
  setOutput: jest.fn(),
  setFailed: jest.fn(),
  error: jest.fn(),
  warning: jest.fn(),
  info: jest.fn(),
  debug: jest.fn()
}));

jest.unstable_mockModule('@actions/github', () => ({
  context: {
    payload: {
      pull_request: {
        number: 123,
        head: {ref: 'head-branch'},
        base: {ref: 'base-branch'}
      }
    },
    repo: {owner: 'monalisa', repo: 'helloworld'}
  },
  getOctokit: jest.fn()
}));

jest.unstable_mockModule('../src/api/index.js', () => ({
  getPullRequests: getPullRequestsMock,
  getLabelConfigs: getLabelConfigsMock,
  addLabels: addLabelsMock,
  removeLabels: removeLabelsMock,
  getChangedFiles: getChangedFilesMock,
  getContent: getContentMock
}));

const core = await import('@actions/core');
const github = await import('@actions/github');
const api = await import('../src/api/index.js');
const {labeler, checkMatchConfigs} = await import('../src/labeler.js');
const {
  toMatchConfig,
  getLabelConfigMapFromObject,
  getLabelConfigResultFromObject,
  configUsesChangedFiles
} = await import('../src/api/get-label-configs.js');

beforeAll(() => {
  (core.getInput as jest.Mock).mockImplementation(() => undefined);
});

const loadYaml = (filepath: string) => {
  const loadedFile = fs.readFileSync(filepath);
  const content = Buffer.from(loadedFile).toString();
  return yaml.load(content);
};

describe('getLabelConfigMapFromObject', () => {
  const yamlObject = loadYaml('__tests__/fixtures/all_options.yml');
  const expected = new Map<string, MatchConfig[]>();
  expected.set('label1', [
    {
      any: [
        {changedFiles: [{anyGlobToAnyFile: ['glob']}]},
        {baseBranch: undefined, headBranch: ['regexp']},
        {baseBranch: ['regexp'], headBranch: undefined}
      ]
    },
    {
      all: [
        {changedFiles: [{allGlobsToAllFiles: ['glob']}]},
        {baseBranch: undefined, headBranch: ['regexp']},
        {baseBranch: ['regexp'], headBranch: undefined}
      ]
    }
  ]);
  expected.set('label2', [
    {
      any: [
        {changedFiles: [{anyGlobToAnyFile: ['glob']}]},
        {baseBranch: undefined, headBranch: ['regexp']},
        {baseBranch: ['regexp'], headBranch: undefined}
      ]
    }
  ]);

  it('returns a MatchConfig', () => {
    const result = getLabelConfigMapFromObject(yamlObject);
    expect(result).toEqual(expected);
  });

  it('ignores top-level options like changed-files-labels-limit and max-files-changed', () => {
    const configWithLimit = {
      'changed-files-labels-limit': 5,
      'max-files-changed': 100,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigMapFromObject(configWithLimit);
    expect(result.has('changed-files-labels-limit')).toBe(false);
    expect(result.has('max-files-changed')).toBe(false);
    expect(result.has('label1')).toBe(true);
  });
});

describe('getLabelConfigResultFromObject', () => {
  it('extracts changed-files-labels-limit as a number', () => {
    const config = {
      'changed-files-labels-limit': 5,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBe(5);
    expect(result.labelConfigs.has('label1')).toBe(true);
  });

  it('parses changed-files-labels-limit from string', () => {
    const config = {
      'changed-files-labels-limit': '10',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBe(10);
  });

  it('trims whitespace when parsing string values', () => {
    const config = {
      'changed-files-labels-limit': ' 5 ',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBe(5);
  });

  it('returns undefined changedFilesLimit when not set', () => {
    const config = {
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBeUndefined();
  });

  it('throws error for invalid changed-files-labels-limit value', () => {
    const config = {
      'changed-files-labels-limit': 'invalid',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /Invalid value for 'changed-files-labels-limit'/
    );
  });

  it('throws error for negative changed-files-labels-limit value', () => {
    const config = {
      'changed-files-labels-limit': -1,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /must be a non-negative integer/
    );
  });

  it('throws error for string with trailing characters', () => {
    const config = {
      'changed-files-labels-limit': '10abc',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /must be a non-negative integer/
    );
  });

  it('throws error for decimal string', () => {
    const config = {
      'changed-files-labels-limit': '3.2',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /must be a non-negative integer/
    );
  });

  it('throws error for float number', () => {
    const config = {
      'changed-files-labels-limit': 3.2,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /must be a non-negative integer/
    );
  });

  it('accepts zero as a valid changed-files-labels-limit', () => {
    const config = {
      'changed-files-labels-limit': 0,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBe(0);
  });

  it('extracts max-files-changed as a number', () => {
    const config = {
      'max-files-changed': 100,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.maxFilesChanged).toBe(100);
    expect(result.labelConfigs.has('label1')).toBe(true);
  });

  it('parses max-files-changed from string', () => {
    const config = {
      'max-files-changed': '50',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.maxFilesChanged).toBe(50);
  });

  it('returns undefined maxFilesChanged when not set', () => {
    const config = {
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.maxFilesChanged).toBeUndefined();
  });

  it('throws error for invalid max-files-changed value', () => {
    const config = {
      'max-files-changed': 'invalid',
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /Invalid value for 'max-files-changed'/
    );
  });

  it('throws error for negative max-files-changed value', () => {
    const config = {
      'max-files-changed': -1,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /must be a non-negative integer/
    );
  });

  it('accepts zero as a valid max-files-changed', () => {
    const config = {
      'max-files-changed': 0,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.maxFilesChanged).toBe(0);
  });

  it('supports both options together', () => {
    const config = {
      'changed-files-labels-limit': 5,
      'max-files-changed': 100,
      label1: [{'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}]
    };
    const result = getLabelConfigResultFromObject(config);
    expect(result.changedFilesLimit).toBe(5);
    expect(result.maxFilesChanged).toBe(100);
  });

  it('throws a clear error when max-files-changed is used as a label', () => {
    const config = {
      'max-files-changed': [
        {'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}
      ]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /reserved top-level option and cannot be used as a label name/
    );
  });

  it('throws a clear error when changed-files-labels-limit is used as a label', () => {
    const config = {
      'changed-files-labels-limit': [
        {'changed-files': [{'any-glob-to-any-file': ['*.txt']}]}
      ]
    };
    expect(() => getLabelConfigResultFromObject(config)).toThrow(
      /reserved top-level option and cannot be used as a label name/
    );
  });
});

describe('toMatchConfig', () => {
  describe('when all expected config options are present', () => {
    const config = {
      'changed-files': [{'any-glob-to-any-file': ['testing-files']}],
      'head-branch': ['testing-head'],
      'base-branch': ['testing-base']
    };
    const expected: BaseMatchConfig = {
      changedFiles: [{anyGlobToAnyFile: ['testing-files']}],
      headBranch: ['testing-head'],
      baseBranch: ['testing-base']
    };

    it('returns a MatchConfig object with all options', () => {
      const result = toMatchConfig(config);
      expect(result).toEqual(expected);
    });

    describe('and there are also unexpected options present', () => {
      config['test-test'] = 'testing';

      it('does not include the unexpected items in the returned MatchConfig object', () => {
        const result = toMatchConfig(config);
        expect(result).toEqual(expected);
      });
    });
  });
});

describe('checkMatchConfigs', () => {
  describe('when a single match config is provided', () => {
    const matchConfig: MatchConfig[] = [
      {any: [{changedFiles: [{anyGlobToAnyFile: ['*.txt']}]}]}
    ];

    it('returns true when our pattern does match changed files', () => {
      const changedFiles = ['foo.txt', 'bar.txt'];
      const result = checkMatchConfigs(changedFiles, matchConfig, false);

      expect(result).toBeTruthy();
    });

    it('returns false when our pattern does not match changed files', () => {
      const changedFiles = ['foo.docx'];
      const result = checkMatchConfigs(changedFiles, matchConfig, false);

      expect(result).toBeFalsy();
    });

    it('returns true when either the branch or changed files patter matches', () => {
      const matchConfig: MatchConfig[] = [
        {
          any: [
            {changedFiles: [{anyGlobToAnyFile: ['*.txt']}]},
            {headBranch: ['some-branch']}
          ]
        }
      ];
      const changedFiles = ['foo.txt', 'bar.txt'];

      const result = checkMatchConfigs(changedFiles, matchConfig, false);
      expect(result).toBe(true);
    });

    it('returns false for a file starting with dot if `dot` option is false', () => {
      const changedFiles = ['.foo.txt'];
      const result = checkMatchConfigs(changedFiles, matchConfig, false);

      expect(result).toBeFalsy();
    });

    it('returns true for a file starting with dot if `dot` option is true', () => {
      const changedFiles = ['.foo.txt'];
      const result = checkMatchConfigs(changedFiles, matchConfig, true);

      expect(result).toBeTruthy();
    });
  });

  describe('when multiple MatchConfigs are supplied', () => {
    const matchConfig: MatchConfig[] = [
      {any: [{changedFiles: [{anyGlobToAnyFile: ['*.txt']}]}]},
      {any: [{headBranch: ['some-branch']}]}
    ];
    const changedFiles = ['foo.txt', 'bar.md'];

    it('returns false when only one config matches', () => {
      const result = checkMatchConfigs(changedFiles, matchConfig, false);
      expect(result).toBe(false);
    });

    it('returns true when only both config matches', () => {
      const matchConfig: MatchConfig[] = [
        {any: [{changedFiles: [{anyGlobToAnyFile: ['*.txt']}]}]},
        {any: [{headBranch: ['head-branch']}]}
      ];
      const result = checkMatchConfigs(changedFiles, matchConfig, false);
      expect(result).toBe(true);
    });
  });
});

describe('configUsesChangedFiles', () => {
  it('returns true when config has changed-files in any block', () => {
    const matchConfig: MatchConfig[] = [
      {any: [{changedFiles: [{anyGlobToAnyFile: ['*.txt']}]}]}
    ];
    expect(configUsesChangedFiles(matchConfig)).toBe(true);
  });

  it('returns true when config has changed-files in all block', () => {
    const matchConfig: MatchConfig[] = [
      {all: [{changedFiles: [{allGlobsToAllFiles: ['*.txt']}]}]}
    ];
    expect(configUsesChangedFiles(matchConfig)).toBe(true);
  });

  it('returns false when config only has branch patterns', () => {
    const matchConfig: MatchConfig[] = [
      {any: [{headBranch: ['^test/']}]},
      {any: [{baseBranch: ['main']}]}
    ];
    expect(configUsesChangedFiles(matchConfig)).toBe(false);
  });

  it('returns false when config has empty changed-files array', () => {
    const matchConfig: MatchConfig[] = [{any: [{changedFiles: []}]}];
    expect(configUsesChangedFiles(matchConfig)).toBe(false);
  });

  it('returns false when config has changed-files with empty objects', () => {
    const matchConfig: MatchConfig[] = [{any: [{changedFiles: [{}]}]}];
    expect(configUsesChangedFiles(matchConfig)).toBe(false);
  });

  it('returns true when config has mixed branch and changed-files patterns', () => {
    const matchConfig: MatchConfig[] = [
      {
        any: [
          {changedFiles: [{anyGlobToAnyFile: ['*.txt']}]},
          {headBranch: ['^feature/']}
        ]
      }
    ];
    expect(configUsesChangedFiles(matchConfig)).toBe(true);
  });
});

describe('labeler error handling', () => {
  const mockClient = {} as any;
  const mockPullRequest = {
    number: 123,
    data: {labels: []},
    changedFiles: []
  };

  beforeEach(() => {
    jest.resetAllMocks();

    (github.getOctokit as jest.Mock).mockReturnValue(mockClient);
    getPullRequestsMock.mockReturnValue([
      {
        ...mockPullRequest,
        data: {labels: [{name: 'old-label'}]}
      }
    ]);

    getLabelConfigsMock.mockResolvedValue({
      labelConfigs: new Map([['new-label', ['dummy-config']]]),
      changedFilesLimit: undefined
    });

    // Force match so "new-label" is always added
    jest.spyOn({checkMatchConfigs}, 'checkMatchConfigs').mockReturnValue(true);
  });

  it('throws a custom error for HttpError 403 with "unauthorized" message', async () => {
    addLabelsMock.mockRejectedValue({
      name: 'HttpError',
      status: 403,
      message: 'Request failed with status code 403: Unauthorized'
    });

    await expect(labeler()).rejects.toThrow(
      /does not have permission to create labels/
    );
  });

  it('rethrows unexpected HttpError', async () => {
    const unexpectedError = {
      name: 'HttpError',
      status: 404,
      message: 'Not Found'
    };
    addLabelsMock.mockRejectedValue(unexpectedError);

    // NOTE: In the current implementation, labeler rethrows the raw error object (not an Error instance).
    // `rejects.toThrow` only works with real Error objects, so here we must use `rejects.toEqual`.
    // If labeler is updated to always wrap errors in `Error`, this test can be changed to use `rejects.toThrow`.
    await expect(labeler()).rejects.toEqual(unexpectedError);
  });

  it('handles "Resource not accessible by integration" gracefully', async () => {
    const error = {
      name: 'HttpError',
      message: 'Resource not accessible by integration'
    };
    addLabelsMock.mockRejectedValue(error);

    await labeler();

    expect(core.warning).toHaveBeenCalledWith(
      expect.stringContaining("requires 'issues: write'"),
      expect.any(Object)
    );
    expect(core.setFailed).toHaveBeenCalledWith(error.message);
  });

  it('reports the configured labels when a bulk removal fails', async () => {
    (core.getBooleanInput as jest.Mock).mockReturnValue(true);
    getPullRequestsMock.mockReturnValue([
      {
        number: 123,
        data: {
          node_id: 'PR_node_id',
          labels: [{name: 'stale-label', node_id: 'label_node_id'}]
        },
        changedFiles: ['file.txt']
      }
    ]);
    getLabelConfigsMock.mockResolvedValue({
      labelConfigs: new Map([
        [
          'stale-label',
          [{any: [{changedFiles: [{anyGlobToAnyFile: ['*.pdf']}]}]}]
        ]
      ]),
      changedFilesLimit: undefined
    });
    removeLabelsMock.mockRejectedValue(new Error('GraphQL request failed'));

    await expect(labeler()).rejects.toThrow(
      "Failed to remove configured labels 'stale-label' from PR #123"
    );
    expect(addLabelsMock).not.toHaveBeenCalled();
  });
});