/**
 * QA-1: Stateful In-Memory-Mock der GerbilManagerWebAPI per Route-Interception.
 *
 * Bedient den DATA-2-Vertrag: Gridify-paged Listen ({items, totalCount, page,
 * pageSize}), camelCase-DTOs, 409 Conflict bei referenzierten Becken/Kontakten
 * (von Dwight bestätigt). Jeder Test bekommt über die Fixture in fixtures.ts
 * einen FRISCHEN Datenbestand — CRUD-Flüsse mutieren ihn wie das echte Backend.
 */
import type { Page, Route } from '@playwright/test'
import { seedDb, type MockDb } from './mock-data'

/** Default-API-Origin des Frontends (src/api/client.ts). */
const API_ORIGIN = 'http://localhost:5179'

type Row = Record<string, unknown>

let seq = 0
const newId = (prefix: string) => `${prefix}-e2e-${++seq}`

/** Gridify-Escapes entfernen (\, vor Sonderzeichen). */
const unescapeGridify = (s: string) => s.replace(/\\(.)/g, '$1')

/** Mini-Gridify: genau die Ausdrücke, die die App baut (==, contains, ',', '|'). */
function matchesFilter(row: Row, filter: string | null): boolean {
  if (!filter) return true
  return filter.split(',').every((andPart) =>
    andPart.split('|').some((cond) => {
      let m = cond.match(/^(\w+)=\*(.*)\*(\/i)?$/)
      if (m) {
        return String(row[m[1]] ?? '')
          .toLowerCase()
          .includes(unescapeGridify(m[2]).toLowerCase())
      }
      m = cond.match(/^(\w+)==(.*)$/)
      if (m) return String(row[m[1]] ?? '') === unescapeGridify(m[2])
      return true
    }),
  )
}

function applyOrderBy(rows: Row[], orderBy: string | null): Row[] {
  if (!orderBy) return rows
  const [field, dir] = orderBy.split(/\s+/)
  const sign = dir?.toLowerCase() === 'desc' ? -1 : 1
  return [...rows].sort((a, b) => {
    const av = String(a[field] ?? '')
    const bv = String(b[field] ?? '')
    return av < bv ? -sign : av > bv ? sign : 0
  })
}

function pagedResponse(rows: Row[], url: URL) {
  const filtered = rows.filter((r) => matchesFilter(r, url.searchParams.get('filter')))
  const sorted = applyOrderBy(filtered, url.searchParams.get('orderBy'))
  const page = Number(url.searchParams.get('page') ?? '1')
  const pageSize = Number(url.searchParams.get('pageSize') ?? '20')
  return {
    items: sorted.slice((page - 1) * pageSize, page * pageSize),
    totalCount: filtered.length,
    page,
    pageSize,
  }
}

const json = (route: Route, status: number, body?: unknown) =>
  route.fulfill({
    status,
    contentType: 'application/json; charset=utf-8',
    body: body === undefined ? '' : JSON.stringify(body),
  })

/**
 * Generische CRUD-Kollektion. `deleteConflict` bildet die 409-Regel des
 * Backends ab (Becken nicht leer / Kontakt referenziert).
 */
function collection(
  rows: Row[],
  idPrefix: string,
  deleteConflict?: (id: string, db: MockDb) => boolean,
) {
  return { rows, idPrefix, deleteConflict }
}

export async function installMockApi(page: Page): Promise<MockDb> {
  const db = seedDb()

  const collections: Record<string, ReturnType<typeof collection>> = {
    gerbils: collection(db.gerbils as unknown as Row[], 'gerbil'),
    litters: collection(db.litters as unknown as Row[], 'litter'),
    enclosures: collection(db.enclosures as unknown as Row[], 'enc', (id, d) =>
      d.gerbils.some((g) => g.enclosureId === id),
    ),
    contacts: collection(db.contacts as unknown as Row[], 'con', (id, d) =>
      d.gerbils.some((g) => g.originContactId === id || g.receiverContactId === id),
    ),
    'color-varieties': collection(db.colorVarieties as unknown as Row[], 'cv'),
    'health-records': collection(db.healthRecords as unknown as Row[], 'hr'),
    'weight-records': collection(db.weightRecords as unknown as Row[], 'wr'),
  }

  const handler = async (route: Route) => {
    const request = route.request()
    const url = new URL(request.url())
    const method = request.method()
    // OPS-1: in Produktion ist die API-Basis der relative Pfad /api (nginx-Proxy);
    // den Präfix normalisieren, damit der Mock unter beiden Basen funktioniert.
    const path = url.pathname.replace(/^\/api(?=\/)/, '')

    // EXPORT-1: Zip-Download (Inhalt egal — der Smoke prüft nur, dass der
    // Download startet; ein leeres Zip = End-of-central-directory-Record).
    if (path === '/export' && method === 'GET') {
      return route.fulfill({
        status: 200,
        contentType: 'application/zip',
        headers: { 'Content-Disposition': 'attachment; filename="rennmaus-export-e2e.zip"' },
        body: Buffer.from([0x50, 0x4b, 0x05, 0x06, ...new Array(18).fill(0)]),
      })
    }

    // FEAT-13: Zuchtprofil (Einstellungen-Seite lädt es vor dem Rendern)
    if (path === '/settings/breeder-profile') {
      if (method === 'GET') {
        return json(route, 200, {
          zuchtName: 'Zucht der kleinen Chaoten',
          name: 'Frau Erika Muster',
          address: 'Musterweg 1, 12345 Musterstadt',
          phone: '', email: '', homepage: '', city: 'Musterstadt',
        })
      }
      if (method === 'PUT') return json(route, 204)
    }

    // Sonderrouten zuerst (FEAT-1b/FEAT-4-Verträge)
    let m = path.match(/^\/gerbils\/([^/]+)\/photos$/)
    if (m) {
      if (method === 'GET') return json(route, 200, [])
      return json(route, 405)
    }
    if (path.match(/^\/photos\/[^/]+$/) && method === 'DELETE') return json(route, 204)
    m = path.match(/^\/gerbils\/([^/]+)\/inbreeding-coefficient$/)
    if (m) {
      const isKruemel = m[1] === 'kruemel'
      return json(route, 200, {
        coefficient: isKruemel ? 0.0625 : 0,
        percent: isKruemel ? 6.25 : 0,
        generationsAvailable: isKruemel ? 5 : 2,
        commonAncestors: isKruemel
          ? [{ id: 'anton', name: 'Anton', contribution: 0.0625 }]
          : [],
      })
    }

    // Generische Kollektionen: /<resource> und /<resource>/<id>
    m = path.match(/^\/([a-z-]+)(?:\/([^/]+))?$/)
    const col = m ? collections[m[1]] : undefined
    if (!m || !col) return json(route, 404, { title: 'Not Found' })
    const id = m[2] ? decodeURIComponent(m[2]) : null

    if (!id) {
      if (method === 'GET') return json(route, 200, pagedResponse(col.rows, url))
      if (method === 'POST') {
        const body = request.postDataJSON() as Row
        const created = { id: newId(col.idPrefix), ...body }
        col.rows.push(created)
        return json(route, 201, created)
      }
      return json(route, 405)
    }

    const idx = col.rows.findIndex((r) => r.id === id)
    if (method === 'GET') {
      return idx >= 0 ? json(route, 200, col.rows[idx]) : json(route, 404, { title: 'Not Found' })
    }
    if (method === 'PUT') {
      if (idx < 0) return json(route, 404, { title: 'Not Found' })
      Object.assign(col.rows[idx], request.postDataJSON() as Row)
      return json(route, 200, col.rows[idx])
    }
    if (method === 'DELETE') {
      if (idx < 0) return json(route, 404, { title: 'Not Found' })
      if (col.deleteConflict?.(id, db)) return json(route, 409, { title: 'Conflict' })
      col.rows.splice(idx, 1)
      return json(route, 204)
    }
    return json(route, 405)
  }

  // Beide API-Basen abfangen: absolute Dev-URL und /api-relativ (OPS-1-Proxy).
  // URL-Prädikat statt Glob: '**/api/**' würde auch Vites Modul-Requests
  // (/src/api/client.ts …) treffen und die App selbst kaputt-intercepten.
  await page.route(
    (url) => url.origin === API_ORIGIN || url.pathname.startsWith('/api/'),
    handler,
  )

  return db
}