/**
 * ExperienceMinerRole - Pattern extraction worker
 * Analyzes completed tasks for reusable patterns.
 * DD §8.4.
 *
 * @module packages/workers/src/roles/ExperienceMinerRole
 */

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

const MEMORY_TYPES = new Set(['project_rule', 'toolchain_rule', 'skill_update', 'debug_experience'])

export interface ExperienceMinerResult {
  status: 'completed' | 'no_patterns' | 'blocked'
  entries: Array<{
    category: string
    pattern: string
    source_task_id: string
    description: string
  }>
  summary: string
}

export class ExperienceMinerRole {
  private runtime: WorkerRuntime

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

  async run(mine_spec: { task_ids?: string[]; focus_categories?: string[]; source_refs?: Array<Record<string, unknown>>; evidence_refs?: string[] }): Promise<ExperienceMinerResult> {
    const result: ExperienceMinerResult = {
      status: 'no_patterns',
      entries: [],
      summary: ''
    }

    try {
      const task_ids = mine_spec.task_ids ?? []
      const evidence_refs = mine_spec.evidence_refs ?? task_ids.map((task_id) => `task:${task_id}`)
      const focus = mine_spec.focus_categories?.length ? mine_spec.focus_categories : ['project_rule', 'toolchain_rule', 'debug_experience']

      if (task_ids.length === 0 && evidence_refs.length === 0) {
        result.summary = 'No task or evidence refs available for memory mining'
        return result
      }

      const messages = [
        { role: 'system', content: 'Extract durable learning candidates only when supported by evidence. Output one candidate per line as memory_type: concise summary. Valid memory_type values: project_rule, toolchain_rule, skill_update, debug_experience. Do not promote or archive memories.' },
        { role: 'user', content: `Evidence refs:\n${evidence_refs.join('\n')}\n\nTask ids: ${task_ids.join(', ') || '(none)'}\nFocus categories: ${focus.join(', ')}` }
      ]

      try {
        const analysis = await this.runtime.call_llm({ messages, max_tokens: 2048, temperature: 0.2 })
        for (const line of (analysis.content || '').split('\n')) {
          const colon_idx = line.indexOf(':')
          if (colon_idx <= 0) continue
          const category = line.slice(0, colon_idx).trim().toLowerCase()
          const memory_type = MEMORY_TYPES.has(category) ? category : 'project_rule'
          const pattern = line.slice(colon_idx + 1).trim()
          if (pattern.length < 8) continue
          result.entries.push({ category: memory_type, pattern, source_task_id: task_ids[0] || '', description: pattern })
        }
      } catch {
        result.entries.push({
          category: 'project_rule',
          pattern: `Review evidence before promoting memory from ${evidence_refs[0] || task_ids[0]}`,
          source_task_id: task_ids[0] || '',
          description: 'LLM unavailable; created a conservative candidate that requires human/runtime review before promotion.',
        })
      }

      if (result.entries.length === 0 && evidence_refs.length > 0) {
        const category = focus.find((item) => MEMORY_TYPES.has(item)) || 'project_rule'
        result.entries.push({
          category,
          pattern: `Review evidence before promoting memory from ${evidence_refs[0]}`,
          source_task_id: task_ids[0] || '',
          description: 'Created a conservative candidate because no structured LLM-supported pattern was returned.',
        })
      }

      for (const entry of result.entries) {
        const candidate_id = `mem_${crypto.randomUUID()}`
        this.runtime.emit('memory.candidate.created', {
          event_id: `evt_${candidate_id}`,
          candidate_id,
          source_ref: {
            entity_type: entry.source_task_id ? 'task' : 'evidence',
            entity_id: entry.source_task_id || evidence_refs[0] || '',
          },
          memory_type: entry.category,
          summary: entry.pattern,
          evidence_refs,
        })
      }

      if (result.entries.length === 0) {
        result.summary = `No supported memory candidates extracted from ${task_ids.length} tasks`
      } else {
        result.status = 'completed'
        result.summary = `Created ${result.entries.length} memory candidates from ${task_ids.length} tasks`
      }

      this.runtime.checkpoint('experience_mining_completed', { candidates: result.entries.length })
      return result

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