export const dynamic = "force-dynamic";

import { z } from "zod";
import { requireAdmin } from "@/lib/auth/session";
import { fail, handleAuthError, ok } from "@/lib/api";
import { prisma } from "@/lib/prisma";
import { getSetting, setSettings } from "@/lib/settings";
import { SETTING_KEYS } from "@/lib/constants";
import { readJsonBody, validateMutationRequestOrigin } from "@/lib/security/request";

const sortSchema = z.enum([
  "date_desc",
  "date_asc",
  "customer_asc",
  "customer_desc",
  "person_asc",
  "person_desc"
]);

const actionSchema = z.object({
  id: z.string().min(1),
  action: z.enum(["archive", "delete"])
});

type GroupedBooking = {
  key: string;
  id: string;
  customerFirstName: string;
  customerLastName: string;
  customerEmail: string;
  startAt: Date;
  staffNames: string[];
  staffCount: number;
};

function parseArchivedKeys(raw: string) {
  try {
    const parsed = JSON.parse(raw);
    if (!Array.isArray(parsed)) return [];
    return parsed
      .map((value) => (typeof value === "string" ? value.trim() : ""))
      .filter((value) => value.length > 0);
  } catch {
    return [];
  }
}

function bookingKey(row: { id: string; bookingGroupId: string | null }) {
  return row.bookingGroupId ?? row.id;
}

function sortBookings(items: GroupedBooking[], sort: z.infer<typeof sortSchema>) {
  const sorted = [...items];

  sorted.sort((a, b) => {
    if (sort === "date_desc") {
      return b.startAt.getTime() - a.startAt.getTime();
    }

    if (sort === "date_asc") {
      return a.startAt.getTime() - b.startAt.getTime();
    }

    if (sort === "customer_asc") {
      return `${a.customerLastName} ${a.customerFirstName}`.localeCompare(
        `${b.customerLastName} ${b.customerFirstName}`
      );
    }

    if (sort === "customer_desc") {
      return `${b.customerLastName} ${b.customerFirstName}`.localeCompare(
        `${a.customerLastName} ${a.customerFirstName}`
      );
    }

    if (sort === "person_asc") {
      return (a.staffNames[0] ?? "").localeCompare(b.staffNames[0] ?? "");
    }

    return (b.staffNames[0] ?? "").localeCompare(a.staffNames[0] ?? "");
  });

  return sorted;
}

export async function GET(req: Request) {
  try {
    await requireAdmin();

    const url = new URL(req.url);
    const parsedSort = sortSchema.safeParse(url.searchParams.get("sort") ?? "date_desc");
    if (!parsedSort.success) {
      return fail("Ungültige Sortierung", 400, parsedSort.error.flatten());
    }

    const archivedRaw = await getSetting(SETTING_KEYS.LATEST_BOOKINGS_ARCHIVED_KEYS);
    const archivedSet = new Set(parseArchivedKeys(archivedRaw));

    const rows = await prisma.appointment.findMany({
      where: {
        status: "CONFIRMED"
      },
      include: {
        staff: {
          select: {
            name: true
          }
        }
      },
      orderBy: {
        startAt: "desc"
      },
      take: 300
    });

    const grouped = new Map<string, GroupedBooking>();
    for (const row of rows) {
      const key = bookingKey(row);
      if (archivedSet.has(key)) continue;

      const existing = grouped.get(key);
      if (!existing) {
        grouped.set(key, {
          key,
          id: row.id,
          customerFirstName: row.customerFirstName,
          customerLastName: row.customerLastName,
          customerEmail: row.customerEmail,
          startAt: row.startAt,
          staffNames: [row.staff.name],
          staffCount: 1
        });
        continue;
      }

      if (!existing.staffNames.includes(row.staff.name)) {
        existing.staffNames.push(row.staff.name);
        existing.staffCount = existing.staffNames.length;
      }
    }

    const sorted = sortBookings(Array.from(grouped.values()), parsedSort.data).slice(0, 50);

    return ok({
      bookings: sorted
    });
  } catch (error) {
    return handleAuthError(error);
  }
}

export async function PATCH(req: Request) {
  try {
    const originError = validateMutationRequestOrigin(req);
    if (originError) return originError;

    await requireAdmin();

    const bodyResult = await readJsonBody(req, { maxBytes: 16 * 1024 });
    if (!bodyResult.ok) return bodyResult.response;
    const parsed = actionSchema.safeParse(bodyResult.data);
    if (!parsed.success) {
      return fail("Ungültige Aktion", 400, parsed.error.flatten());
    }

    const target = await prisma.appointment.findUnique({
      where: {
        id: parsed.data.id
      },
      select: {
        id: true,
        bookingGroupId: true
      }
    });

    if (!target) {
      return fail("Buchung nicht gefunden", 404);
    }

    const key = bookingKey(target);

    if (parsed.data.action === "archive") {
      const archivedRaw = await getSetting(SETTING_KEYS.LATEST_BOOKINGS_ARCHIVED_KEYS);
      const archived = new Set(parseArchivedKeys(archivedRaw));
      archived.add(key);

      await setSettings({
        [SETTING_KEYS.LATEST_BOOKINGS_ARCHIVED_KEYS]: JSON.stringify(Array.from(archived))
      });

      return ok({ message: "Buchung archiviert." });
    }

    if (target.bookingGroupId) {
      await prisma.appointment.deleteMany({
        where: {
          bookingGroupId: target.bookingGroupId
        }
      });
    } else {
      await prisma.appointment.delete({
        where: {
          id: target.id
        }
      });
    }

    const archivedRaw = await getSetting(SETTING_KEYS.LATEST_BOOKINGS_ARCHIVED_KEYS);
    const archived = parseArchivedKeys(archivedRaw).filter((entry) => entry !== key);
    await setSettings({
      [SETTING_KEYS.LATEST_BOOKINGS_ARCHIVED_KEYS]: JSON.stringify(archived)
    });

    return ok({ message: "Buchung gelöscht." });
  } catch (error) {
    return handleAuthError(error);
  }
}