"use server"

import { revalidatePath } from "next/cache"
import { and, eq } from "drizzle-orm"
import { db } from "@/lib/db"
import { account_deletion_requests } from "@/lib/db/schema"
import { getSessionUser, isAdminUser } from "@/lib/session"
import { LEGAL } from "@/lib/legal"
import { sendEmail, accountDeletionRequestedHtml } from "@/lib/email/send"

// ============================================================================
// GDPR self-service actions (Settings → Privacy & Data).
//
// Deletion is a two-step, grace-period flow: the request schedules a hard
// delete LEGAL.dataDeletionDays out (the retention window promised on /gdpr);
// the gdpr cron executes it. Until then the account stays usable and the user
// can cancel. Data export is a GET route (/api/gdpr/export), not an action,
// so the browser can download it as a file.
// ============================================================================

const SETTINGS_PATH = "/settings/privacy"

export type DeletionRequestDTO = {
  id: string
  status: "pending" | "cancelled" | "completed"
  scheduled_for: string
  created_at: string
}

export async function requestAccountDeletion(input: {
  confirmEmail: string
  reason?: string
}): Promise<DeletionRequestDTO> {
  const user = await getSessionUser()
  if (!user) throw new Error("Unauthorized")

  // Admins manage the platform — deleting one from self-service risks locking
  // everyone out. They can be removed via the admin panel by another admin.
  if (isAdminUser(user as { id?: string; email?: string; role?: string | null })) {
    throw new Error("Admin accounts cannot be deleted from self-service. Contact another administrator.")
  }

  const typed = (input.confirmEmail ?? "").trim().toLowerCase()
  if (!typed || typed !== user.email.toLowerCase()) {
    throw new Error("The email you typed doesn't match your account email.")
  }

  const existing = await db.query.account_deletion_requests.findFirst({
    where: and(
      eq(account_deletion_requests.user_id, user.id),
      eq(account_deletion_requests.status, "pending")
    ),
  })
  if (existing) throw new Error("Your account is already scheduled for deletion.")

  const scheduledFor = new Date(Date.now() + LEGAL.dataDeletionDays * 24 * 60 * 60 * 1000).toISOString()

  let row: typeof account_deletion_requests.$inferSelect
  try {
    ;[row] = await db
      .insert(account_deletion_requests)
      .values({
        user_id: user.id,
        email: user.email,
        reason: (input.reason ?? "").trim().slice(0, 500) || null,
        scheduled_for: scheduledFor,
      })
      .returning()
  } catch {
    // The partial unique index makes a double-submit race land here.
    throw new Error("Your account is already scheduled for deletion.")
  }

  await sendEmail({
    to: user.email,
    subject: "Your account deletion is scheduled",
    html: accountDeletionRequestedHtml({
      name: user.name || user.email,
      scheduledDate: new Date(scheduledFor).toLocaleDateString("en-US", {
        year: "numeric",
        month: "long",
        day: "numeric",
      }),
      graceDays: LEGAL.dataDeletionDays,
    }),
  })

  revalidatePath(SETTINGS_PATH)
  return { id: row.id, status: row.status, scheduled_for: row.scheduled_for, created_at: row.created_at }
}

export async function cancelAccountDeletion(): Promise<void> {
  const user = await getSessionUser()
  if (!user) throw new Error("Unauthorized")

  const [row] = await db
    .update(account_deletion_requests)
    .set({ status: "cancelled", cancelled_at: new Date().toISOString() })
    .where(
      and(
        eq(account_deletion_requests.user_id, user.id),
        eq(account_deletion_requests.status, "pending")
      )
    )
    .returning({ id: account_deletion_requests.id })
  if (!row) throw new Error("No pending deletion request found.")

  revalidatePath(SETTINGS_PATH)
}