import type { IndexedFile, IndexEntry, Node, WorkspaceIndex } from './contract'
import { describe, expect, it } from 'vitest'
import { createPythonAdapter } from './languages/python'
import { MemoryIndexHost, WASM_DIR } from './testSupport'
import { WorkspaceIndexes } from './workspaceIndex'

const py = createPythonAdapter(WASM_DIR)

/** 测试用的索引：每个函数一项，键是「包路径:函数名」，文件所在目录有 __init__.py 时包路径是目录，否则是空的。 */
function functionIndex(seen: string[] = []): WorkspaceIndex {
  return {
    id: 'test.functions',
    languageId: 'python',
    include: '**/*.py',
    mentions: source => source.includes('def '),
    entries: (root: Node, file: IndexedFile): IndexEntry[] => {
      seen.push(file.path)
      const directory = file.path.split('/').slice(0, -1).join('/')
      const prefix = file.exists(`${directory}/./__init__.py`) ? directory : ''
      return root.descendantsOfType('function_definition').flatMap((fn) => {
        const name = fn?.childForFieldName('name')
        return name ? [{ key: `${prefix}:${name.text}`, name: { startIndex: name.startIndex, endIndex: name.endIndex } }] : []
      })
    },
  }
}

function setup(files: Record<string, string>): { host: MemoryIndexHost, indexes: WorkspaceIndexes } {
  const host = new MemoryIndexHost(files, py)
  return { host, indexes: new WorkspaceIndexes(host) }
}

describe('工作区索引', () => {
  it('第一次查才建；查到的是名字的行列（列按 UTF-16 算），照文件、行排好', async () => {
    const { host, indexes } = setup({
      'b.py': '# 中文注释\ndef load():\n    pass\n',
      'a.py': 'def load():\n    pass\n\n\ndef load():\n    pass\n',
      'notes.txt': 'def load():',
    })
    expect(host.lists).toBe(0)
    expect(await indexes.lookup(functionIndex(), ':load')).toEqual([
      { uri: 'file:///w/a.py', start: { line: 0, character: 4 }, end: { line: 0, character: 8 } },
      { uri: 'file:///w/a.py', start: { line: 4, character: 4 }, end: { line: 4, character: 8 } },
      { uri: 'file:///w/b.py', start: { line: 1, character: 4 }, end: { line: 1, character: 8 } },
    ])
    expect(await indexes.lookup(functionIndex(), ':missing')).toEqual([])
    expect(host.lists).toBe(1)
  })

  it('预筛不过的文件不解析', async () => {
    const seen: string[] = []
    const { indexes } = setup({ 'a.py': 'def a(): pass\n', 'b.py': 'x = 1\n' })
    await indexes.lookup(functionIndex(seen), ':a')
    expect(seen).toEqual(['a.py'])
  })

  it('文件改了只重看那一份；新建的加进来；删掉的目录连里面的文件一起去掉', async () => {
    const { host, indexes } = setup({ 'a.py': 'def a(): pass\n', 'pkg/b.py': 'def b(): pass\n', 'pkg/deep/c.py': 'def c(): pass\n' })
    const index = functionIndex()
    await indexes.lookup(index, ':a')
    host.reads.length = 0

    host.emit('change', 'a.py', 'def renamed(): pass\n')
    expect(await indexes.lookup(index, ':a')).toEqual([])
    expect(await indexes.lookup(index, ':renamed')).toHaveLength(1)
    expect(host.reads).toEqual(['a.py'])

    host.emit('create', 'd.py', '\n\ndef d(): pass\n')
    expect((await indexes.lookup(index, ':d'))[0].start).toEqual({ line: 2, character: 4 })

    host.emit('delete', 'pkg')
    expect(await indexes.lookup(index, ':b')).toEqual([])
    expect(await indexes.lookup(index, ':c')).toEqual([])
    expect(host.reads).toEqual(['a.py', 'd.py'])
  })

  it('新建、删掉别的文件问过在不在的文件（__init__.py）时，问过它的文件跟着重看', async () => {
    const { host, indexes } = setup({ 'pkg/mod.py': 'def run(): pass\n', 'other.py': 'def other(): pass\n' })
    const index = functionIndex()
    expect(await indexes.lookup(index, ':run')).toHaveLength(1)
    host.reads.length = 0

    host.emit('create', 'pkg/__init__.py', '')
    expect(await indexes.lookup(index, 'pkg:run')).toHaveLength(1)
    expect(host.reads.sort()).toEqual(['pkg/__init__.py', 'pkg/mod.py'])

    host.emit('delete', 'pkg/__init__.py')
    expect(await indexes.lookup(index, ':run')).toHaveLength(1)
  })

  it('建索引期间的改动建好后补上', async () => {
    const { host, indexes } = setup({ 'a.py': 'def a(): pass\n' })
    const index = functionIndex()
    const first = indexes.lookup(index, ':a')
    host.emit('change', 'a.py', 'def b(): pass\n')
    await first
    expect(await indexes.lookup(index, ':b')).toHaveLength(1)
    expect(await indexes.lookup(index, ':a')).toEqual([])
  })

  it('读不了、规则出错的文件记下来，别的照常', async () => {
    const { host, indexes } = setup({ 'a.py': 'def a(): pass\n', 'bad.py': 'def boom(): pass\n' })
    host.files.delete('bad.py')
    host.files.set('b.py', 'def b(): pass\n')
    const index = functionIndex()
    const broken: WorkspaceIndex = {
      ...index,
      id: 'test.broken',
      entries: (root, file) => {
        if (file.path === 'a.py')
          throw new Error('认不了')
        return index.entries(root, file)
      },
    }
    // bad.py 在找到的文件里，读的时候已经没了
    host.list = async () => ['a.py', 'bad.py', 'b.py'].map(relative => host.file(relative))
    expect(await indexes.lookup(broken, ':b')).toHaveLength(1)
    expect([...host.reports].sort()).toEqual([
      '索引 test.broken 看 file:///w/a.py 时出错：认不了',
      '索引 test.broken 读不了 file:///w/bad.py：没有 bad.py',
    ])
  })

  it('同一个 id 只建一份；dispose 后不再盯着文件', async () => {
    const { host, indexes } = setup({ 'a.py': 'def a(): pass\n' })
    await indexes.lookup(functionIndex(), ':a')
    await indexes.lookup(functionIndex(), ':a')
    expect(host.lists).toBe(1)
    expect(host.watching).toBe(1)
    indexes.dispose()
    expect(host.watching).toBe(0)
  })
})