import { randomUUID } from "crypto"
import { NextResponse } from "next/server"
import { touchUpdatedAt } from "@/lib/content-audit"
import { Prisma } from "@prisma/client"
import { prisma } from "@/lib/prisma"
import { getCurrentUser, isAllowedRole } from "@/lib/user"
import {
  ABOUT_US_PAGE_ENTITY_KEY,
  ABOUT_US_PAGE_LOCALE_CODES,
  type AboutUsPageLocaleCode,
} from "@/lib/pages/about-us/locales"
import {
  parseAboutUsPageJsonForStorage,
  parseAboutUsPagePutBody,
  type AboutUsPageSectionKey,
} from "@/lib/pages/about-us/validate-payload"
import {
  createEmptyAboutUsPageFormState,
  type AboutUsPageFormStateShape,
} from "@/lib/pages/about-us/form-types"
import { normalizeAboutUsLocaleImagesForStorage } from "@/lib/pages/about-us/hero-fallback"
import { deleteImage, extractMediaKeyFromUrl } from "@/lib/r2-storage"
import {
  getPersistedMediaValidationError,
  normalizePersistedMediaInPayload,
} from "@/lib/media-manager/validate-persisted-payload"

export const dynamic = "force-dynamic"
export const revalidate = 0

const NO_CACHE_HEADERS = {
  "Cache-Control": "no-store, no-cache, must-revalidate, proxy-revalidate",
  Pragma: "no-cache",
  Expires: "0",
}

async function ensureAdmin() {
  const user = await getCurrentUser()
  if (!user) return { ok: false as const, res: NextResponse.json({ error: "Unauthorized" }, { status: 401, headers: NO_CACHE_HEADERS }) }
  if (!isAllowedRole(user.role, ["admin"])) return { ok: false as const, res: NextResponse.json({ error: "Forbidden" }, { status: 403, headers: NO_CACHE_HEADERS }) }
  return { ok: true as const, user }
}

function rowToFormState(contentJson: unknown): AboutUsPageFormStateShape {
  let parsed: unknown = contentJson
  if (typeof contentJson === "string") {
    try {
      parsed = JSON.parse(contentJson)
    } catch {
      parsed = undefined
    }
  }
  return parseAboutUsPageJsonForStorage(parsed).data
}

function resolveAboutUsImagePublicIdForDelete(hero: AboutUsPageFormStateShape["hero"]): string | null {
  const explicit = (hero.imagePublicId ?? "").trim()
  if (explicit.startsWith("about-us/")) return explicit
  return extractMediaKeyFromUrl(hero.image, { prefix: "about-us" })
}

function buildMergedLocalesForSectionSave(
  existingByLocale: Partial<Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape>>,
  incomingLocales: Record<string, AboutUsPageFormStateShape>,
  sectionKey: AboutUsPageSectionKey
): Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape> {
  const next: Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape> = {
    en: createEmptyAboutUsPageFormState(),
    tr: createEmptyAboutUsPageFormState(),
    ar: createEmptyAboutUsPageFormState(),
  }

  for (const locale of ABOUT_US_PAGE_LOCALE_CODES) {
    const base = existingByLocale[locale] ?? createEmptyAboutUsPageFormState()
    const incoming = incomingLocales[locale] ?? base
    next[locale] = {
      ...base,
      [sectionKey]: incoming[sectionKey],
    }
  }

  return next
}

export async function GET() {
  const auth = await ensureAdmin()
  if (!auth.ok) return auth.res

  try {
    const rows = await prisma.aboutUsPageLocale.findMany({
      where: { entityKey: ABOUT_US_PAGE_ENTITY_KEY },
      orderBy: { locale: "asc" },
    })
    const locales: Partial<Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape>> = {}
    for (const row of rows) {
      if (!ABOUT_US_PAGE_LOCALE_CODES.includes(row.locale as AboutUsPageLocaleCode)) continue
      const code = row.locale as AboutUsPageLocaleCode
      locales[code] = rowToFormState(row.contentJson)
    }
    return NextResponse.json(
      { success: true as const, locales: normalizeAboutUsLocaleImagesForStorage(locales) },
      { headers: NO_CACHE_HEADERS }
    )
  } catch (error) {
    console.error("[admin/about-us] GET error:", error)
    return NextResponse.json({ success: false as const, error: "Failed to load about us page" }, { status: 500, headers: NO_CACHE_HEADERS })
  }
}

export async function PUT(req: Request) {
  const auth = await ensureAdmin()
  if (!auth.ok) return auth.res

  let body: unknown
  try {
    body = await req.json()
  } catch {
    return NextResponse.json({ success: false as const, error: "Invalid JSON body" }, { status: 400, headers: NO_CACHE_HEADERS })
  }

  const normalizedBody = normalizePersistedMediaInPayload(body)
  const mediaError = getPersistedMediaValidationError(normalizedBody)
  if (mediaError) {
    return NextResponse.json({ success: false as const, error: mediaError }, { status: 400, headers: NO_CACHE_HEADERS })
  }

  const parsed = parseAboutUsPagePutBody(normalizedBody)
  if (!parsed.ok) {
    return NextResponse.json({ success: false as const, error: parsed.error }, { status: 400, headers: NO_CACHE_HEADERS })
  }

  try {
    const existingRows = await prisma.aboutUsPageLocale.findMany({
      where: { entityKey: ABOUT_US_PAGE_ENTITY_KEY },
      select: { locale: true, contentJson: true },
    })
    const existingByLocale: Partial<Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape>> = {}
    for (const row of existingRows) {
      if (!ABOUT_US_PAGE_LOCALE_CODES.includes(row.locale as AboutUsPageLocaleCode)) continue
      existingByLocale[row.locale as AboutUsPageLocaleCode] = rowToFormState(row.contentJson)
    }
    const localesToPersist =
      parsed.data.sectionKey
        ? buildMergedLocalesForSectionSave(existingByLocale, parsed.data.locales, parsed.data.sectionKey)
        : (parsed.data.locales as Record<AboutUsPageLocaleCode, AboutUsPageFormStateShape>)
    const normalizedLocales = normalizeAboutUsLocaleImagesForStorage(localesToPersist)

    const previousImagePublicIds = new Set<string>()
    for (const row of existingRows) {
      const state = rowToFormState(row.contentJson)
      const publicId = resolveAboutUsImagePublicIdForDelete(state.hero)
      if (publicId) previousImagePublicIds.add(publicId)
    }
    const nextImagePublicIds = new Set<string>()
    for (const state of Object.values(normalizedLocales)) {
      const publicId = resolveAboutUsImagePublicIdForDelete(state.hero)
      if (publicId) nextImagePublicIds.add(publicId)
    }

    const localeNow = new Date()
    const ops = (Object.entries(normalizedLocales) as [AboutUsPageLocaleCode, AboutUsPageFormStateShape][]).map(
      ([locale, state]) =>
        prisma.aboutUsPageLocale.upsert({
          where: { entityKey_locale: { entityKey: ABOUT_US_PAGE_ENTITY_KEY, locale } },
          create: {
            id: randomUUID(),
            updatedAt: localeNow,
            entityKey: ABOUT_US_PAGE_ENTITY_KEY,
            locale,
            contentJson: JSON.stringify(state),
          },
          update: { ...touchUpdatedAt(), contentJson: JSON.stringify(state) },
        })
    )
    await prisma.$transaction(ops)

    const stalePublicIds = [...previousImagePublicIds].filter((id) => id.startsWith("about-us/") && !nextImagePublicIds.has(id))
    if (stalePublicIds.length > 0) {
      await Promise.allSettled(stalePublicIds.map((id) => deleteImage(id)))
    }
  } catch (error) {
    console.error("[admin/about-us] PUT error:", error)
    return NextResponse.json({ success: false as const, error: "Failed to save about us page" }, { status: 500, headers: NO_CACHE_HEADERS })
  }

  return NextResponse.json({ success: true as const }, { headers: NO_CACHE_HEADERS })
}