import { describe, it, expect, beforeEach } from 'vitest'
import { mkdtempSync } from 'fs'
import { tmpdir } from 'os'
import { join } from 'path'
import { openSessionsDb, type SessionsDb, type PatternRecord } from '../services/sessions/db.js'
import { detectPatterns, weekRange, toPatternRecord } from '../services/sessions/patterns.js'
import type { SessionMeta } from '../types/session.js'

function meta(overrides: Partial<SessionMeta>): SessionMeta {
  return {
    session_id: 's-' + Math.random().toString(36).slice(2, 10),
    project_path: '/tmp/project',
    project_slug: 'project',
    jsonl_path: '/tmp/' + Math.random().toString(36).slice(2) + '.jsonl',
    started_at: '2026-04-20T10:00:00Z', // segunda de 2026-W17
    ended_at: '2026-04-20T10:30:00Z',
    duration_sec: 1800,
    event_count: 50,
    user_messages: 5,
    assistant_msgs: 10,
    tool_calls: 20,
    first_prompt: 'olá',
    tools_used: ['Bash'],
    skills_invoked: [],
    outcome: 'completed',
    permission_mode: 'default',
    file_size: 10000,
    indexed_at: '2026-04-20T10:31:00Z',
    ...overrides,
  }
}

describe('patterns detector', () => {
  let db: SessionsDb
  beforeEach(() => {
    const dir = mkdtempSync(join(tmpdir(), 'obs-pat-'))
    db = openSessionsDb(join(dir, 'sessions.db'))
  })

  it('detecta skill com taxa elevada de erro (action)', () => {
    // 3 sessões skill X: 2 error, 1 completed → ratio 0.67 → severity=action
    db.upsertSession(meta({ session_id: 'a', skills_invoked: ['skillX'], outcome: 'error' }))
    db.upsertSession(meta({ session_id: 'b', skills_invoked: ['skillX'], outcome: 'interrupted' }))
    db.upsertSession(meta({ session_id: 'c', skills_invoked: ['skillX'], outcome: 'completed' }))
    const { start, end } = weekRange(new Date('2026-04-22T00:00:00Z'))
    const patterns = detectPatterns(db, start, end)
    const errorRate = patterns.find((p) => p.pattern_key === 'skill_error_rate:skillX')
    expect(errorRate).toBeDefined()
    expect(errorRate!.severity).toBe('action')
    expect(errorRate!.affected_count).toBe(2)
  })

  it('detecta sessões abandonadas', () => {
    for (let i = 0; i < 6; i++) {
      db.upsertSession(meta({ session_id: `ab-${i}`, event_count: 1, outcome: 'unknown' }))
    }
    const { start, end } = weekRange(new Date('2026-04-22T00:00:00Z'))
    const patterns = detectPatterns(db, start, end)
    expect(patterns.some((p) => p.pattern_key === 'abandoned_sessions')).toBe(true)
  })

  it('getConsecutiveWeeks devolve 3 após upserts em semanas sucessivas', () => {
    const key = 'skill_error_rate:Y'
    const weeks = ['2026-W15', '2026-W16', '2026-W17']
    for (const w of weeks) {
      db.upsertPattern({
        detected_at: new Date().toISOString(),
        week_iso: w,
        pattern_key: key,
        title: 't',
        description: 'd',
        severity: 'warning',
        metric_value: 0.5,
        sample_session_ids: ['x'],
        affected_count: 1,
        consecutive_weeks: 1,
      })
    }
    expect(db.getConsecutiveWeeks(key, '2026-W17')).toBe(3)
    expect(db.getConsecutiveWeeks(key, '2026-W16')).toBe(2)
  })

  it('upsertPattern é idempotente por (week_iso, pattern_key)', () => {
    const base: PatternRecord = {
      detected_at: '2026-04-20T00:00:00Z',
      week_iso: '2026-W17',
      pattern_key: 'test',
      title: 'v1',
      description: 'd',
      severity: 'info',
      metric_value: 1,
      sample_session_ids: ['a'],
      affected_count: 1,
      consecutive_weeks: 1,
    }
    db.upsertPattern(base)
    db.upsertPattern({ ...base, title: 'v2', affected_count: 5, consecutive_weeks: 2 })
    const rows = db.getPatternsByWeek('2026-W17')
    expect(rows).toHaveLength(1)
    expect(rows[0].title).toBe('v2')
    expect(rows[0].affected_count).toBe(5)
    expect(rows[0].consecutive_weeks).toBe(2)
  })

  it('toPatternRecord propaga week_iso e consecutive_weeks', () => {
    const rec = toPatternRecord(
      {
        pattern_key: 'k',
        title: 't',
        description: 'd',
        severity: 'warning',
        metric_value: 0.42,
        sample_session_ids: ['a', 'b'],
        affected_count: 2,
      },
      '2026-W17',
      3,
    )
    expect(rec.week_iso).toBe('2026-W17')
    expect(rec.consecutive_weeks).toBe(3)
    expect(rec.severity).toBe('warning')
  })
})