import { expect, test } from '@playwright/test'

import { loginAsBaselineUser } from '../utils/auth'
import { readFixtures } from '../utils/fixtures'

// =============================================================================
// TEST-CONTRACT-001 — 409 conflict shape on optimistic-locking failure
// =============================================================================
//
// Why this test exists:
// ---------------------
// The timetable-stabilization sprint's B5 incident (commit ff056e3)
// caught a schema-drift bug where the frontend's Zod schema for
// MoveTimetableConflictResponse diverged from the backend's response
// shape. Vitest+jsdom tests passed because they mocked both sides.
// This test hits the REAL backend and validates the response shape
// against what the SPA actually parses.
//
// Scenario:
// ---------
// 1. Login as e2e@test.local (seeded via E2EBaselineSeeder).
// 2. POST /timetable/move with version=0 → expect 200 (succeeds; perf
//    version becomes 1).
// 3. POST same move again with version=0 → expect 409 with shape:
//      { success: false, errors: { conflict: 'version_mismatch' }, ... }
// 4. Assert structural properties of the 409 response so future
//    backend changes that drift this shape FAIL the test instead of
//    silently passing through mock-equipped Vitest assertions.
//
// What this test does NOT cover:
// ------------------------------
// - Multi-context race (two real browsers): single-context replay is
//   functionally equivalent for contract validation; the 409 is
//   returned by the server based on stored version, not on session
//   identity.
// - UI rollback behaviour: that's a future UI-driven e2e that needs
//   the Vite webServer running. Out of B4 scope.
// - Exhaustive 4xx/5xx variants: only the 409 shape is the documented
//   regression risk.
// =============================================================================

test.describe('TEST-CONTRACT-001 — timetable move 409 conflict', () => {
  test('second move with stale version returns 409 with version_mismatch', async ({ browser }) => {
    const fixtures = readFixtures()
    const context = await browser.newContext({ baseURL: process.env.E2E_API_URL ?? 'http://localhost:8001' })
    const { request, organisationId } = await loginAsBaselineUser(context)

    expect(organisationId).toBe(fixtures.organisation_id)

    const moveUrl = `/api/v1/organisations/${fixtures.organisation_id}/events/${fixtures.event_id}/timetable/move`

    // Use a stable target time independent of the original seed, so
    // we control where the perf lands. Take the seeded perf's
    // engagement window and shift by an hour.
    const targetStart = new Date()

    targetStart.setUTCDate(targetStart.getUTCDate() + 2)
    targetStart.setUTCHours(21, 0, 0, 0) // 23:00 Europe/Amsterdam summer

    const targetEnd = new Date(targetStart.getTime() + 60 * 60 * 1000)

    const fmt = (d: Date) => d.toISOString().slice(0, 19).replace('T', ' ')

    const movePayload = {
      performance_id: fixtures.performance_id,
      target_stage_id: fixtures.stage_id,
      target_start_at: fmt(targetStart),
      target_end_at: fmt(targetEnd),
      target_lane: 0,
      version: 0,
    }

    // -----------------------------------------------------------------
    // First move: expect 200, perf.version moves 0 → 1
    // -----------------------------------------------------------------
    const first = await request.post(moveUrl, {
      data: movePayload,
      headers: {
        'Content-Type': 'application/json',
        'Idempotency-Key': 'e2e-409-first',
      },
    })

    expect(first.status(), `First move expected 200, got ${first.status()}: ${await first.text()}`).toBe(200)

    // -----------------------------------------------------------------
    // Second move with the SAME (now-stale) version=0: expect 409
    // -----------------------------------------------------------------
    const second = await request.post(moveUrl, {
      data: movePayload,
      headers: {
        'Content-Type': 'application/json',
        'Idempotency-Key': 'e2e-409-second',
      },
    })

    expect(second.status()).toBe(409)

    const conflictBody = await second.json() as {
      success?: boolean
      message?: string
      errors?: { conflict?: string }
    }

    // Contract assertions — drift here means the SPA's Zod schema for
    // MoveTimetableConflictResponse needs an update.
    expect(conflictBody.errors?.conflict).toBe('version_mismatch')
    expect(typeof conflictBody.message).toBe('string')

    await context.close()
  })
})