import type { BlockKind, CodeBlock, LanguageAdapter } from './contract'
import { readFileSync } from 'node:fs'
import * as path from 'node:path'
import { TreeSitterRuntime } from './runtime'

/** 单元测试直接用依赖包里的 wasm，不走打包产物。 */
export const WASM_DIR = path.resolve(__dirname, '../../node_modules/@vscode/tree-sitter-wasm/wasm')

export const runtime = new TreeSitterRuntime(WASM_DIR)

export function readFixture(name: string): string {
  return readFileSync(path.join(__dirname, 'fixtures', name), 'utf8')
}

/** 解析 source，把代码块树交给 use；语法树随后释放。 */
export async function withBlocks<T>(adapter: LanguageAdapter, languageId: string, source: string, use: (blocks: CodeBlock[]) => T): Promise<T> {
  const tree = await runtime.parse(adapter, languageId, source)
  try {
    return use(adapter.toBlocks(tree.rootNode, source))
  }
  finally {
    tree.delete()
  }
}

/** 和原型 CODE_TREE 同样的写法：at 是 1 起的行号（单行，或 [起, 止]）。 */
export interface Outline { at: number | [number, number], kind: BlockKind, kids?: Outline[] }

export function outline(blocks: CodeBlock[]): Outline[] {
  return blocks.map((block) => {
    const from = block.header.startRow + 1
    const to = block.header.endRow + 1
    const item: Outline = { at: from === to ? from : [from, to], kind: block.kind }
    if (block.children.length > 0)
      item.kids = outline(block.children)
    return item
  })
}

export function walk(blocks: CodeBlock[], visit: (block: CodeBlock) => void): void {
  for (const block of blocks) {
    visit(block)
    walk(block.children, visit)
  }
}