/**
 * ExecutorRole - Implementation worker
 * Implements DD §8.4. Executes tasks using LLM→tool→LLM loop.
 * Accepts natural LLM output (code blocks, tool calls, direct writing).
 *
 * @module packages/workers/src/roles/ExecutorRole
 */

import { WorkerRuntime } from '../WorkerRuntime.js'

export interface ExecutorResult {
  status: 'completed' | 'failed' | 'blocked'
  changes?: Array<{ file: string; type: 'create' | 'edit' | 'delete' }>
  verification?: { passed: boolean; output: string }
  error?: string
  evidence_refs?: string[]
}

type ExecutorAction =
  | { type: 'text' }
  | { type: 'code_block'; filename: string; content: string }
  | { type: 'tool_call'; id: string; name: string; args: Record<string, unknown> }

export class ExecutorRole {
  private runtime: WorkerRuntime
  private max_turns: number = 15

  constructor(runtime: WorkerRuntime) {
    this.runtime = runtime
  }

  async run(task_spec: { id: string; title: string; description: string; acceptance_criteria: string[] }): Promise<ExecutorResult> {
    this.runtime.checkpoint('task_attempt_started', { task_id: task_spec.id })

    const model = (task_spec as any).model || process.env.AIRCODING_MODEL || 'glm-5.1'
    const projectRoot = process.env.AIRCODING_PROJECT_ROOT || '.'

    try {
      const messages: Array<{ role: string; content: unknown }> = [
        {
          role: 'system',
          content: `You are an AI coding assistant. Complete coding tasks by writing code files.

Use structured tool calls whenever possible. Available tools include:
  - fs.read, fs.write, fs.edit, fs.list — filesystem operations
  - shell.run — shell command execution
  - cpp.detect, cpp.configure, cpp.build, cpp.test, cpp.cppcheck, cpp.clangd — C++ toolchain

If native tools are unavailable, output strict JSON tool calls only in this form:

\`\`\`json
{"tool":"fs.write","args":{"path":"src/main.cpp","content":"..."}}
\`\`\`

You may write new files by outputting code blocks with a language tag that includes the filename:
\`\`\`cpp:src/main.cpp
// C++ code here
\`\`\`

After all required files are written and required verification has passed, write a line containing exactly: DONE`
        },
        {
          role: 'user',
          content: `Task: ${task_spec.title}\n\nDescription: ${task_spec.description}\n\nAcceptance criteria:\n${task_spec.acceptance_criteria.map((c, i) => `${i + 1}. ${c}`).join('\n')}\n\nProject directory: ${projectRoot}`
        }
      ]

      let turn = 0
      const changes: Array<{ file: string; type: 'create' | 'edit' | 'delete' }> = []

      while (turn < this.max_turns) {
        turn++
        this.runtime.heartbeat()

        const llm_response = await this.runtime.call_llm({
          messages,
          model,
          max_tokens: 8192,
          temperature: 0.2
        })

        let text = (llm_response.content || '')
          .replace(/<\/?think>/g, '')
          .replace(/<\|assistant\|>/g, '')
          .trim()

        // Parse structured actions from native tool_calls first, then strict JSON/code-block fallback
        const actions = this.parse_actions(text, llm_response.tool_calls || [])

        // Debug
        const actionSummary = actions.map(a => {
          if (a.type === 'code_block') return `📄 ${(a as any).filename} (${(a as any).content.length}B)`
          if (a.type === 'tool_call') return `🔧 ${(a as any).name}`
          return `💬 text`
        }).join(', ')
        process.stderr.write(`[EXEC T${turn}] ${actionSummary}\n`)

        // Execute all actions
        const hadActions = actions.some(a => a.type !== 'text')
        let allSucceeded = true

        if (hadActions) {
          messages.push({ role: 'assistant', content: this.assistant_content_for_actions(text, actions) })

          for (const action of actions) {
            if (action.type === 'code_block') {
              const { filename, content } = action as { filename: string; content: string }
              try {
                const result = await this.runtime.call_tool('fs.write', { path: filename, content, create_dirs: true })
                if (result.type === 'error') {
                  allSucceeded = false
                  messages.push({ role: 'user', content: `Failed to write ${filename}: ${JSON.stringify(result.content)}` })
                } else {
                  changes.push({ file: filename, type: 'create' })
                  messages.push({ role: 'user', content: `✅ ${filename} written (${content.length} bytes)` })
                }
              } catch (e: any) {
                allSucceeded = false
                messages.push({ role: 'user', content: `Error writing ${filename}: ${e.message}` })
              }
            } else if (action.type === 'tool_call') {
              const { id, name, args } = action as { id: string; name: string; args: Record<string, unknown> }
              try {
                const result = await this.runtime.call_tool(name, args)
                const output = result.type === 'error'
                  ? `Error: ${JSON.stringify(result.content)}`
                  : JSON.stringify(result.content)
                if (name === 'fs.write' && args.path) changes.push({ file: args.path as string, type: 'create' })
                if (name === 'fs.edit' && args.path) changes.push({ file: args.path as string, type: 'edit' })
                if (result.type === 'error') allSucceeded = false
                messages.push({
                  role: 'user',
                  content: [{ type: 'tool_result', tool_use_id: id, content: output.slice(0, 5000), is_error: result.type === 'error' }]
                })
              } catch (e: any) {
                allSucceeded = false
                messages.push({
                  role: 'user',
                  content: [{ type: 'tool_result', tool_use_id: id, content: `Tool ${name} error: ${e.message}`, is_error: true }]
                })
              }
            }
          }

          if (this.is_done_signal(text)) {
            if (!allSucceeded) {
              messages.push({ role: 'assistant', content: text })
              messages.push({ role: 'user', content: 'You signaled DONE, but one or more tool actions failed. Fix the failed actions before signaling DONE.' })
              continue
            }
            const verification = await this.verify_before_completion(task_spec, changes)
            if (!verification.passed) {
              messages.push({ role: 'user', content: `Verification failed; do not say DONE until fixed.\n${verification.output}` })
              continue
            }
            await this.runtime.checkpoint('task_completed', { task_id: task_spec.id })
            return {
              status: 'completed',
              changes,
              verification,
              evidence_refs: []
            }
          }

          // ALWAYS ask the LLM: are you done or do you need to create more files?
          messages.push({
            role: 'user',
            content: allSucceeded
              ? `Actions completed. ${changes.length} files written so far: ${changes.map(c => c.file).join(', ')}.\nIf the task needs MORE files, continue creating them.\nIf the task is COMPLETE (all required files created), respond with DONE.`
              : 'Some actions failed. Review the errors and retry. If all attempts exhausted, respond with DONE to finish with partial results.'
          })
        } else {
          // No code blocks, no tool calls — LLM is just talking
          if (this.is_done_signal(text)) {
            if (changes.length === 0) {
              messages.push({ role: 'assistant', content: text })
              messages.push({ role: 'user', content: 'You said DONE but no files were created. Please create the required files first.' })
              continue
            }
            const verification = await this.verify_before_completion(task_spec, changes)
            if (!verification.passed) {
              messages.push({ role: 'user', content: `Verification failed; do not say DONE until fixed.\n${verification.output}` })
              continue
            }
            await this.runtime.checkpoint('task_completed', { task_id: task_spec.id })
            return {
              status: 'completed',
              changes,
              verification,
              evidence_refs: []
            }
          }

          messages.push({ role: 'assistant', content: text })
          messages.push({ role: 'user', content: 'Please CREATE the files. Use native tools, strict JSON tool_call blocks, or code blocks with filename tags. When done creating ALL files and required verification passes, respond DONE.' })
        }
      }

      return {
        status: 'blocked',
        error: `Task exceeded ${this.max_turns} turns (${changes.length} files created)`,
        changes,
        evidence_refs: []
      }

    } catch (error) {
      return { status: 'blocked', error: error instanceof Error ? error.message : String(error) }
    }
  }

  private is_done_signal(text: string): boolean {
    return text
      .split(/\r?\n/)
      .map(line => line.trim())
      .some(line => line === 'DONE' || line === 'TASK_COMPLETE')
  }

  private async verify_before_completion(
    task_spec: { acceptance_criteria: string[]; title: string; description: string },
    changes: Array<{ file: string; type: 'create' | 'edit' | 'delete' }>
  ): Promise<{ passed: boolean; output: string }> {
    if (!this.requires_executable_verification(task_spec)) {
      return { passed: true, output: `${changes.length} files: ${changes.map(c => c.file).join(', ')}` }
    }

    const command = this.verification_command(task_spec, changes)
    if (!command) {
      return { passed: false, output: 'Acceptance criteria require executable verification, but no verification command could be derived.' }
    }

    const result = await this.runtime.call_tool('shell.run', { command, timeout: 300000 })
    const payload = result.content as { exit_code?: number; stdout?: string; stderr?: string; message?: string }
    if (result.type === 'error') {
      return {
        passed: false,
        output: `Verification command failed: ${command}\n${payload.stderr || payload.stdout || payload.message || JSON.stringify(payload)}`,
      }
    }

    return {
      passed: true,
      output: `Verification command passed: ${command}\n${payload.stdout || ''}`.trim(),
    }
  }

  private requires_executable_verification(task_spec: { acceptance_criteria: string[]; title: string; description: string }): boolean {
    const text = `${task_spec.title}\n${task_spec.description}\n${task_spec.acceptance_criteria.join('\n')}`.toLowerCase()
    return /\b(build|compile|run|test|cmake|make|pytest|npm test|bun test)\b|编译|构建|运行|测试/.test(text)
  }

  private verification_command(
    task_spec: { title: string; description: string; acceptance_criteria: string[] },
    changes: Array<{ file: string; type: 'create' | 'edit' | 'delete' }>
  ): string | null {
    const text = `${task_spec.title}\n${task_spec.description}\n${task_spec.acceptance_criteria.join('\n')}`.toLowerCase()
    const files = new Set(changes.map(c => c.file))

    if (files.has('CMakeLists.txt') || text.includes('cmake')) {
      return 'cmake -S . -B build && cmake --build build'
    }
    if ([...files].some(f => f.endsWith('.cpp') || f.endsWith('.cc') || f.endsWith('.cxx'))) {
      const file = [...files].find(f => f.endsWith('.cpp') || f.endsWith('.cc') || f.endsWith('.cxx')) || 'main.cpp'
      return `c++ ${file} -o /tmp/aircoding-verify && /tmp/aircoding-verify`
    }
    if (files.has('package.json') || text.includes('npm test')) return 'npm test'
    if (text.includes('bun test')) return 'bun test'
    if ([...files].some(f => f.endsWith('.py')) && text.includes('test')) return 'python3 -m pytest'
    return null
  }

  /**
   * Parse structured actions from native tool calls and strict JSON fallback.
   */
  private parse_actions(
    text: string,
    native_tool_calls: Array<{ id?: string; name: string; arguments: Record<string, unknown> }> = []
  ): ExecutorAction[] {
    const actions: ExecutorAction[] = []

    for (const call of native_tool_calls) {
      actions.push({
        type: 'tool_call',
        id: call.id || crypto.randomUUID(),
        name: call.name,
        args: call.arguments || {},
      })
    }

    const codeBlockRe = /```(\w+)(?::(\S+)|\s+(\S+))?\s*\n([\s\S]*?)```/g
    for (const match of text.matchAll(codeBlockRe)) {
      const lang = match[1]
      const inner = match[4].trim()
      if (lang === 'json' || lang === 'tool' || lang === 'tool_call') {
        const parsed = this.parse_json_tool_call(inner)
        if (parsed) actions.push(parsed)
        continue
      }

      let filename = match[2] || match[3] || ''
      if (!filename || filename.length < 2) {
        const extMap: Record<string, string> = {
          cpp: 'main.cpp', c: 'main.c', h: 'header.h', hpp: 'header.hpp',
          cmake: 'CMakeLists.txt', python: 'script.py', py: 'script.py',
          js: 'script.js', ts: 'script.ts', json: 'config.json',
          yaml: 'config.yaml', yml: 'config.yml', toml: 'config.toml',
          md: 'README.md', txt: 'output.txt', sh: 'script.sh',
          bash: 'script.sh', Makefile: 'Makefile',
        }
        filename = extMap[lang] || `${lang}_output.${lang === 'cmake' ? 'txt' : lang}`
      }

      actions.push({ type: 'code_block', filename, content: match[4] })
    }

    const textWithoutBlocks = text.replace(/```(?:\w+)?[\s\S]*?```/g, '')
    actions.push(...this.extract_json_tool_calls(textWithoutBlocks))

    if (actions.length === 0) actions.push({ type: 'text' })
    return actions
  }

  private parse_json_tool_call(raw: string): Extract<ExecutorAction, { type: 'tool_call' }> | null {
    try {
      const parsed = JSON.parse(raw) as { id?: string; tool?: string; name?: string; args?: Record<string, unknown>; arguments?: Record<string, unknown> }
      const name = parsed.tool || parsed.name
      if (!name) return null
      return {
        type: 'tool_call',
        id: parsed.id || crypto.randomUUID(),
        name,
        args: parsed.args || parsed.arguments || {},
      }
    } catch {
      return null
    }
  }

  private extract_json_tool_calls(text: string): ExecutorAction[] {
    const actions: ExecutorAction[] = []
    for (const line of text.split(/\r?\n/)) {
      const trimmed = line.trim()
      if (!trimmed.startsWith('{') || !trimmed.endsWith('}')) continue
      const action = this.parse_json_tool_call(trimmed)
      if (action) actions.push(action)
    }
    return actions
  }

  private assistant_content_for_actions(text: string, actions: ExecutorAction[]): unknown {
    const toolUses = actions
      .filter((a): a is Extract<ExecutorAction, { type: 'tool_call' }> => a.type === 'tool_call')
      .map(a => ({ type: 'tool_use', id: a.id, name: a.name, input: a.args }))

    if (toolUses.length === 0) return text

    const blocks: Array<Record<string, unknown>> = []
    const cleanText = text.replace(/```(?:tool_call|tool|json)\s*\n?[\s\S]*?```/g, '').trim()
    if (cleanText) blocks.push({ type: 'text', text: cleanText })
    blocks.push(...toolUses)
    return blocks
  }
}