import { readdirSync, statSync } from 'fs'
import { homedir } from 'os'
import { join } from 'path'
import { parseSessionFile } from './parser.js'
import { openSessionsDb, type SessionsDb } from './db.js'
import { indexHermesSessions } from './hermes-indexer.js'
import { indexOCSessions } from './opencode-indexer.js'
import type { SessionMeta } from '../../types/session.js'

export const PROJECTS_ROOT = join(homedir(), '.claude', 'projects')
export const DEFAULT_DB_PATH = join(homedir(), '.claude-work', 'sessions.db')

/**
 * Percorre a raiz de projectos Claude (profundidade 2) e devolve todos os .jsonl.
 * Estrutura: ~/.claude/projects/<project-slug>/<session-uuid>.jsonl
 */
export function findAllJsonl(root: string = PROJECTS_ROOT): string[] {
  const result: string[] = []
  let entries: string[]
  try {
    entries = readdirSync(root)
  } catch {
    return result
  }
  for (const entry of entries) {
    const projectDir = join(root, entry)
    let st
    try {
      st = statSync(projectDir)
    } catch {
      continue
    }
    if (!st.isDirectory()) continue
    let files: string[]
    try {
      files = readdirSync(projectDir)
    } catch {
      continue
    }
    for (const f of files) {
      if (f.endsWith('.jsonl')) result.push(join(projectDir, f))
    }
  }
  return result
}

/**
 * Indexa um único ficheiro (parse + upsert). Uso individual — útil para o watcher (Task 8).
 */
export async function indexFile(db: SessionsDb, path: string): Promise<void> {
  const { meta } = await parseSessionFile(path)
  db.upsertSession(meta)
}

export interface IndexAllOptions {
  dbPath?: string
  sources?: ('claude' | 'hermes' | 'opencode')[]
  onProgress?: (done: number, total: number) => void
}

/**
 * Full scan: indexa Claude Code (JSONL) + Hermes (state.db) + OpenCode (opencode.db).
 */
export async function indexAll(
  options: IndexAllOptions = {},
): Promise<{ indexed: number; failed: number }> {
  const sources = options.sources ?? ['claude', 'hermes', 'opencode']
  let indexed = 0
  let failed = 0
  const dbPath = options.dbPath ?? DEFAULT_DB_PATH

  if (sources.includes('claude')) {
    const db = openSessionsDb(dbPath)
    const files = findAllJsonl()
    const BATCH = 50
    let batch: SessionMeta[] = []

    try {
      for (let i = 0; i < files.length; i++) {
        try {
          const { meta } = await parseSessionFile(files[i])
          meta.source = 'claude'
          meta.model = meta.model ?? null
          meta.ended_at = meta.ended_at ?? null
          meta.duration_sec = meta.duration_sec ?? null
          meta.input_tokens = meta.input_tokens ?? null
          meta.output_tokens = meta.output_tokens ?? null
          meta.estimated_cost = meta.estimated_cost ?? null
          meta.first_prompt = meta.first_prompt ?? null
          meta.permission_mode = meta.permission_mode ?? null
          meta.project_path = meta.project_path ?? null
          meta.project_slug = meta.project_slug ?? null
          meta.jsonl_path = meta.jsonl_path ?? null
          batch.push(meta)
          if (batch.length >= BATCH) {
            db.upsertMany(batch)
            indexed += batch.length
            batch = []
          }
        } catch (err) {
          failed++
          console.error(`[indexer] erro em ${files[i]}:`, err)
        }
        if (options.onProgress) {
          options.onProgress(indexed + failed + batch.length, files.length)
        }
      }
      if (batch.length > 0) {
        db.upsertMany(batch)
        indexed += batch.length
      }
    } finally {
      db.close()
    }
  }

  if (sources.includes('hermes')) {
    try {
      const result = await indexHermesSessions({ dbPath })
      indexed += result.indexed
      failed += result.failed
      console.log(`[indexer] Hermes: ${result.indexed} indexadas, ${result.failed} falhas`)
    } catch (err) {
      failed++
      console.error('[indexer] Erro ao indexar Hermes:', err)
    }
  }

  if (sources.includes('opencode')) {
    try {
      const result = await indexOCSessions({ dbPath })
      indexed += result.indexed
      failed += result.failed
      console.log(`[indexer] OpenCode: ${result.indexed} indexadas, ${result.failed} falhas`)
    } catch (err) {
      failed++
      console.error('[indexer] Erro ao indexar OpenCode:', err)
    }
  }

  return { indexed, failed }
}