import { describe, expect, test } from "bun:test";

import {
  adjustIndentation,
  findAllMatches,
  findMatch,
} from "../tools/filesystem/fuzzy-match.js";

describe("findMatch", () => {
  test('exact match returns method "exact"', () => {
    const content = 'function hello() {\n  return "world";\n}';
    const target = 'return "world";';
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("exact");
    expect(result!.similarity).toBe(1);
    expect(result!.matched).toBe('return "world";');
  });

  test("whitespace normalization: 2-space indent matches 4-space", () => {
    const content = '    function hello() {\n        return "world";\n    }';
    const target = '  function hello() {\n    return "world";\n  }';
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("whitespace");
    expect(result!.matched).toBe(
      '    function hello() {\n        return "world";\n    }',
    );
  });

  test("tabs vs spaces: tab-indented target matches space-indented file", () => {
    const content = "    const x = 1;\n    const y = 2;";
    const target = "\tconst x = 1;\n\tconst y = 2;";
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("whitespace");
  });

  test("trailing whitespace: target with trailing spaces matches file without", () => {
    const content = "const x = 1;\nconst y = 2;";
    const target = "const x = 1;   \nconst y = 2;  ";
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("whitespace");
  });

  test('fuzzy match: minor typo matches with method "fuzzy"', () => {
    const content = "const value = 42;\nconst other = 10;";
    const target = "cosnt value = 42;\nconst other = 10;";
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("fuzzy");
    expect(result!.similarity).toBeGreaterThanOrEqual(0.8);
  });

  test("no match: completely different string returns null", () => {
    const content = 'function hello() {\n  return "world";\n}';
    const target = "class Foo extends Bar {\n  constructor() {}\n}";
    const result = findMatch(content, target);
    expect(result).toBeNull();
  });

  test("below threshold: similarity too low returns null", () => {
    const content = "abcdefghij";
    const target = "zyxwvutsrq";
    const result = findMatch(content, target);
    expect(result).toBeNull();
  });

  test("prefers exact match over whitespace match", () => {
    const content = "  const x = 1;";
    const target = "  const x = 1;";
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("exact");
  });

  test("single-line whitespace match", () => {
    const content = "if (x) {\n    return true;\n}";
    const target = "\treturn true;";
    const result = findMatch(content, target);
    expect(result).not.toBeNull();
    expect(result!.method).toBe("whitespace");
    expect(result!.matched).toBe("    return true;");
  });
});

describe("findAllMatches", () => {
  test("returns multiple exact matches", () => {
    const content = "foo bar foo baz foo";
    const target = "foo";
    const results = findAllMatches(content, target);
    expect(results.length).toBe(3);
    results.forEach((r) => expect(r.method).toBe("exact"));
  });

  test("returns multiple whitespace matches", () => {
    const content = "begin\n    const x = 1;\nmiddle\n    const x = 1;\nend";
    const target = "\tconst x = 1;";
    const results = findAllMatches(content, target);
    expect(results.length).toBe(2);
    results.forEach((r) => expect(r.method).toBe("whitespace"));
  });

  test("returns empty array for no match", () => {
    const content = "hello world";
    const target = "goodbye universe";
    const results = findAllMatches(content, target);
    expect(results.length).toBe(0);
  });
});

describe("adjustIndentation", () => {
  test("adds indentation when file has more than old_string", () => {
    const oldString = "  function foo() {\n    return 1;\n  }";
    const matched = "    function foo() {\n      return 1;\n    }";
    const newString = "  function foo() {\n    return 2;\n  }";
    const result = adjustIndentation(oldString, matched, newString);
    expect(result).toBe("    function foo() {\n      return 2;\n    }");
  });

  test("removes indentation when file has less than old_string", () => {
    const oldString = "    function foo() {\n      return 1;\n    }";
    const matched = "  function foo() {\n    return 1;\n  }";
    const newString = "    function foo() {\n      return 2;\n    }";
    const result = adjustIndentation(oldString, matched, newString);
    expect(result).toBe("  function foo() {\n    return 2;\n  }");
  });

  test("no change when indentation matches", () => {
    const oldString = "  return 1;";
    const matched = "  return 1;";
    const newString = "  return 2;";
    const result = adjustIndentation(oldString, matched, newString);
    expect(result).toBe("  return 2;");
  });

  test("preserves empty lines", () => {
    const oldString = "  const a = 1;\n\n  const b = 2;";
    const matched = "    const a = 1;\n\n    const b = 2;";
    const newString = "  const a = 10;\n\n  const b = 20;";
    const result = adjustIndentation(oldString, matched, newString);
    expect(result).toBe("    const a = 10;\n\n    const b = 20;");
  });
});