/**
 * Sync Module Tests
 *
 * Tests for sync functionality (incremental updates).
 * Note: Git hooks functionality has been removed in favor of codegraph's
 * Claude Code hooks integration.
 */

import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';
import { execFileSync } from 'child_process';
import CodeGraph from '../src/index';

describe('Sync Module', () => {
  describe('Sync Functionality', () => {
    let testDir: string;
    let cg: CodeGraph;

    beforeEach(async () => {
      testDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-sync-func-'));

      // Create initial source files
      const srcDir = path.join(testDir, 'src');
      fs.mkdirSync(srcDir);
      fs.writeFileSync(
        path.join(srcDir, 'index.ts'),
        `export function hello() { return 'world'; }`
      );

      // Initialize and index
      cg = CodeGraph.initSync(testDir, {
        config: {
          include: ['**/*.ts'],
          exclude: [],
        },
      });
      await cg.indexAll();
    });

    afterEach(() => {
      if (cg) {
        cg.destroy();
      }
      if (fs.existsSync(testDir)) {
        fs.rmSync(testDir, { recursive: true, force: true });
      }
    });

    describe('getChangedFiles()', () => {
      it('should detect added files', () => {
        // Add a new file
        fs.writeFileSync(
          path.join(testDir, 'src', 'new.ts'),
          `export function newFunc() { return 42; }`
        );

        const changes = cg.getChangedFiles();

        expect(changes.added).toContain('src/new.ts');
        expect(changes.modified).toHaveLength(0);
        expect(changes.removed).toHaveLength(0);
      });

      it('should detect modified files', () => {
        // Modify existing file
        fs.writeFileSync(
          path.join(testDir, 'src', 'index.ts'),
          `export function hello() { return 'modified'; }`
        );

        const changes = cg.getChangedFiles();

        expect(changes.added).toHaveLength(0);
        expect(changes.modified).toContain('src/index.ts');
        expect(changes.removed).toHaveLength(0);
      });

      it('should detect removed files', () => {
        // Remove file
        fs.unlinkSync(path.join(testDir, 'src', 'index.ts'));

        const changes = cg.getChangedFiles();

        expect(changes.added).toHaveLength(0);
        expect(changes.modified).toHaveLength(0);
        expect(changes.removed).toContain('src/index.ts');
      });
    });

    describe('sync()', () => {
      it('should reindex added files', async () => {
        // Add a new file
        fs.writeFileSync(
          path.join(testDir, 'src', 'new.ts'),
          `export function newFunc() { return 42; }`
        );

        const result = await cg.sync();

        expect(result.filesAdded).toBe(1);
        expect(result.filesModified).toBe(0);
        expect(result.filesRemoved).toBe(0);

        // Verify new function is in the graph
        const nodes = cg.searchNodes('newFunc');
        expect(nodes.length).toBeGreaterThan(0);
      });

      it('should reindex modified files', async () => {
        // Modify existing file
        fs.writeFileSync(
          path.join(testDir, 'src', 'index.ts'),
          `export function goodbye() { return 'farewell'; }`
        );

        const result = await cg.sync();

        expect(result.filesModified).toBe(1);

        // Verify new function is in the graph
        const nodes = cg.searchNodes('goodbye');
        expect(nodes.length).toBeGreaterThan(0);

        // Verify old function is gone
        const oldNodes = cg.searchNodes('hello');
        expect(oldNodes.length).toBe(0);
      });

      it('should remove nodes from deleted files', async () => {
        // Remove file
        fs.unlinkSync(path.join(testDir, 'src', 'index.ts'));

        const result = await cg.sync();

        expect(result.filesRemoved).toBe(1);

        // Verify function is gone
        const nodes = cg.searchNodes('hello');
        expect(nodes.length).toBe(0);
      });

      it('should report no changes when nothing changed', async () => {
        const result = await cg.sync();

        expect(result.filesAdded).toBe(0);
        expect(result.filesModified).toBe(0);
        expect(result.filesRemoved).toBe(0);
        expect(result.filesChecked).toBeGreaterThan(0);
      });
    });
  });

  describe('Git-based sync', () => {
    let testDir: string;
    let cg: CodeGraph;

    function git(...args: string[]) {
      execFileSync('git', args, { cwd: testDir, stdio: 'pipe' });
    }

    beforeEach(async () => {
      testDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-git-sync-'));

      // Initialize a git repo with an initial commit
      git('init');
      git('config', 'user.email', 'test@test.com');
      git('config', 'user.name', 'Test');

      const srcDir = path.join(testDir, 'src');
      fs.mkdirSync(srcDir);
      fs.writeFileSync(
        path.join(srcDir, 'index.ts'),
        `export function hello() { return 'world'; }`
      );

      git('add', '-A');
      git('commit', '-m', 'initial');

      // Initialize CodeGraph and index
      cg = CodeGraph.initSync(testDir, {
        config: {
          include: ['**/*.ts'],
          exclude: [],
        },
      });
      await cg.indexAll();
    });

    afterEach(() => {
      if (cg) {
        cg.destroy();
      }
      if (fs.existsSync(testDir)) {
        fs.rmSync(testDir, { recursive: true, force: true });
      }
    });

    it('should detect modified files via git', async () => {
      fs.writeFileSync(
        path.join(testDir, 'src', 'index.ts'),
        `export function hello() { return 'modified'; }`
      );

      const result = await cg.sync();

      expect(result.filesModified).toBe(1);
      expect(result.changedFilePaths).toContain('src/index.ts');
    });

    it('should detect new untracked files via git', async () => {
      fs.writeFileSync(
        path.join(testDir, 'src', 'new.ts'),
        `export function newFunc() { return 42; }`
      );

      const result = await cg.sync();

      expect(result.filesAdded).toBe(1);
      expect(result.changedFilePaths).toContain('src/new.ts');

      // Verify the function was indexed
      const nodes = cg.searchNodes('newFunc');
      expect(nodes.length).toBeGreaterThan(0);
    });

    it('should stop reporting untracked files once they are indexed (issue #206)', async () => {
      // Untracked files stay `??` in git status even after codegraph indexes
      // them. Change detection must compare them against the DB by hash, not
      // report every untracked file as "added" on every sync/status.
      fs.writeFileSync(
        path.join(testDir, 'src', 'new.ts'),
        `export function newFunc() { return 42; }`
      );

      // First sync indexes the untracked file.
      const first = await cg.sync();
      expect(first.filesAdded).toBe(1);

      // The file is still untracked in git, but now lives in the DB.
      expect(cg.searchNodes('newFunc').length).toBeGreaterThan(0);

      // status must not keep flagging it as a pending addition...
      const changes = cg.getChangedFiles();
      expect(changes.added).not.toContain('src/new.ts');
      expect(changes.modified).not.toContain('src/new.ts');

      // ...and a second sync must be a no-op for it.
      const second = await cg.sync();
      expect(second.filesAdded).toBe(0);
      expect(second.filesModified).toBe(0);
    });

    it('should re-index an untracked file when its contents change', async () => {
      const filePath = path.join(testDir, 'src', 'new.ts');
      fs.writeFileSync(filePath, `export function newFunc() { return 42; }`);
      await cg.sync();

      // Modify the still-untracked file.
      fs.writeFileSync(filePath, `export function renamedFunc() { return 7; }`);

      const changes = cg.getChangedFiles();
      expect(changes.modified).toContain('src/new.ts');

      const result = await cg.sync();
      expect(result.filesModified).toBe(1);
      expect(cg.searchNodes('renamedFunc').length).toBeGreaterThan(0);
      expect(cg.searchNodes('newFunc').length).toBe(0);
    });

    it('should detect deleted files via git', async () => {
      fs.unlinkSync(path.join(testDir, 'src', 'index.ts'));

      const result = await cg.sync();

      expect(result.filesRemoved).toBe(1);

      // Verify function is gone
      const nodes = cg.searchNodes('hello');
      expect(nodes.length).toBe(0);
    });

    it('should skip files with unsupported extensions', async () => {
      // A .txt file has no supported grammar, so sync must not index it.
      fs.writeFileSync(
        path.join(testDir, 'src', 'notes.txt'),
        `just some notes`
      );

      const result = await cg.sync();

      expect(result.filesAdded).toBe(0);
      expect(result.filesModified).toBe(0);
    });

    it('should report no changes on clean working tree', async () => {
      const result = await cg.sync();

      expect(result.filesAdded).toBe(0);
      expect(result.filesModified).toBe(0);
      expect(result.filesRemoved).toBe(0);
      expect(result.changedFilePaths).toBeUndefined();
    });
  });

  describe('Cross-file module-attribute caller edges survive callee re-index (#899)', () => {
    let testDir: string;
    let cg: CodeGraph;

    beforeEach(async () => {
      testDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-899-'));

      // pkg/mod.py — a module with two functions, both called from a separate
      // test file via `mod.<fn>(...)` (module-attribute access). This is the
      // exact shape from the RAGFlow production case in issue #899.
      fs.mkdirSync(path.join(testDir, 'pkg'), { recursive: true });
      fs.mkdirSync(path.join(testDir, 'test'), { recursive: true });
      fs.writeFileSync(
        path.join(testDir, 'pkg', '__init__.py'),
        ``
      );
      fs.writeFileSync(
        path.join(testDir, 'pkg', 'mod.py'),
        [
          `def callee_one(value):`,
          `    """First callee — docstring above the second callee so edits here shift its line."""`,
          `    return value + 1`,
          ``,
          ``,
          `def callee_two(value):`,
          `    """Second callee, called from the test file via mod.callee_two(...)."""`,
          `    return value + 2`,
          ``,
        ].join('\n')
      );
      fs.writeFileSync(
        path.join(testDir, 'test', 'test_callers.py'),
        [
          `from pkg import mod`,
          ``,
          ``,
          `def test_calls_callee_one():`,
          `    assert mod.callee_one(1) == 2`,
          ``,
          ``,
          `def test_calls_callee_two():`,
          `    assert mod.callee_two(1) == 3`,
          ``,
        ].join('\n')
      );

      cg = CodeGraph.initSync(testDir, {
        config: { include: ['**/*.py'], exclude: [] },
      });
      await cg.indexAll();
    });

    afterEach(() => {
      if (cg) cg.destroy();
      if (fs.existsSync(testDir)) fs.rmSync(testDir, { recursive: true, force: true });
    });

    function callerCount(fnName: string): number {
      const results = cg.searchNodes(fnName);
      const def = results.map(r => r.node).find(n => n.kind === 'function' && n.name === fnName);
      if (!def) return -1;
      return cg.getCallers(def.id).length;
    }

    it('preserves incoming cross-file calls edges when the callee file is re-indexed', async () => {
      // Baseline: both callees have one cross-file caller each.
      expect(callerCount('callee_one')).toBe(1);
      expect(callerCount('callee_two')).toBe(1);

      // Docstring-only edit to callee_one — adds 1 line, shifting callee_two's
      // line number. A naive ID-based edge restore would drop callee_two's
      // incoming edge (its node id changed); the (kind, name) re-resolve
      // preserves it. A docstring-only edit also confirms zero-AST-change
      // re-indexes don't sever edges.
      fs.writeFileSync(
        path.join(testDir, 'pkg', 'mod.py'),
        [
          `def callee_one(value):`,
          `    """First callee — docstring above the second callee so edits here shift its line."""`,
          `    """Probe: extra docstring line to shift callee_two's start line by 1."""`,
          `    return value + 1`,
          ``,
          ``,
          `def callee_two(value):`,
          `    """Second callee, called from the test file via mod.callee_two(...)."""`,
          `    return value + 2`,
          ``,
        ].join('\n')
      );

      const result = await cg.sync();
      expect(result.filesModified).toBe(1);

      // Both incoming cross-file calls edges must survive the callee re-index.
      expect(callerCount('callee_one')).toBe(1);
      expect(callerCount('callee_two')).toBe(1);
    });

    it('drops incoming edges for a callee that was renamed during re-index', async () => {
      // Baseline.
      expect(callerCount('callee_one')).toBe(1);

      // Rename callee_one -> callee_one_renamed. The old edge's target
      // (kind=function, name=callee_one) no longer matches any re-indexed
      // node, so the edge is correctly dropped (not preserved against a
      // non-existent symbol).
      fs.writeFileSync(
        path.join(testDir, 'pkg', 'mod.py'),
        [
          `def callee_one_renamed(value):`,
          `    """Renamed callee — the old edge targeting callee_one must not be restored."""`,
          `    return value + 1`,
          ``,
          ``,
          `def callee_two(value):`,
          `    """Second callee, called from the test file via mod.callee_two(...)."""`,
          `    return value + 2`,
          ``,
        ].join('\n')
      );

      await cg.sync();

      // The renamed callee has no callers (the test still calls mod.callee_one,
      // which no longer exists). The old callee_one node is gone, so its
      // callerCount is -1 (definition not found); callee_one_renamed exists
      // but has no incoming edges (the test calls the old name).
      expect(callerCount('callee_one')).toBe(-1);
      expect(callerCount('callee_one_renamed')).toBe(0);
      // callee_two is untouched by the rename and its edge survives.
      expect(callerCount('callee_two')).toBe(1);
    });
  });
});