// ABOUTME: API route for editing and deleting individual period logs.
// ABOUTME: PATCH updates startDate, DELETE removes period entry.
import type { NextRequest } from "next/server";
import { NextResponse } from "next/server";
import type PocketBase from "pocketbase";

import { withAuth } from "@/lib/auth-middleware";
import type { PeriodLog, User } from "@/types";

// Date format regex: YYYY-MM-DD
const DATE_REGEX = /^\d{4}-\d{2}-\d{2}$/;

interface RouteContext {
  params?: Promise<{ id: string }>;
}

// Helper to format date as YYYY-MM-DD
function formatDateStr(date: Date): string {
  return date.toISOString().split("T")[0];
}

// Helper to check if a period log is the most recent for a user
async function isMostRecentPeriod(
  pb: PocketBase,
  userId: string,
  periodLogId: string,
): Promise<boolean> {
  const result = await pb.collection("period_logs").getList<PeriodLog>(1, 1, {
    filter: `user="${userId}"`,
    sort: "-startDate",
  });

  if (result.items.length === 0) {
    return false;
  }

  return result.items[0].id === periodLogId;
}

// Helper to get the most recent period after deletion
async function getMostRecentPeriodAfterDeletion(
  pb: PocketBase,
  userId: string,
): Promise<PeriodLog | null> {
  const result = await pb.collection("period_logs").getList<PeriodLog>(1, 1, {
    filter: `user="${userId}"`,
    sort: "-startDate",
  });

  return result.items[0] || null;
}

export const PATCH = withAuth(
  async (
    request: NextRequest,
    user: User,
    pb: PocketBase,
    context?: RouteContext,
  ) => {
    // Get ID from route params
    const { id } = await (context?.params ?? Promise.resolve({ id: "" }));

    // Fetch the period log
    let periodLog: PeriodLog;
    try {
      periodLog = await pb.collection("period_logs").getOne<PeriodLog>(id);
    } catch (error) {
      // Handle PocketBase 404 errors (can be Error or plain object)
      const err = error as { status?: number };
      if (err.status === 404) {
        return NextResponse.json(
          { error: "Period log not found" },
          { status: 404 },
        );
      }
      throw error;
    }

    // Check ownership
    if (periodLog.user !== user.id) {
      return NextResponse.json({ error: "Access denied" }, { status: 403 });
    }

    // Parse request body
    const body = await request.json();

    // Validate startDate is present
    if (!body.startDate) {
      return NextResponse.json(
        { error: "startDate is required" },
        { status: 400 },
      );
    }

    // Validate startDate format
    if (!DATE_REGEX.test(body.startDate)) {
      return NextResponse.json(
        { error: "startDate must be in YYYY-MM-DD format" },
        { status: 400 },
      );
    }

    // Validate startDate is a valid date
    const parsedDate = new Date(body.startDate);
    if (Number.isNaN(parsedDate.getTime())) {
      return NextResponse.json(
        { error: "startDate is not a valid date" },
        { status: 400 },
      );
    }

    // Validate startDate is not in the future
    const today = new Date();
    today.setHours(23, 59, 59, 999); // End of today
    if (parsedDate > today) {
      return NextResponse.json(
        { error: "startDate cannot be in the future" },
        { status: 400 },
      );
    }

    // Update the period log
    const updatedPeriodLog = await pb
      .collection("period_logs")
      .update<PeriodLog>(id, {
        startDate: body.startDate,
      });

    // If this is the most recent period, update user.lastPeriodDate
    const isLatest = await isMostRecentPeriod(pb, user.id, id);
    if (isLatest) {
      await pb.collection("users").update(user.id, {
        lastPeriodDate: body.startDate,
      });
    }

    return NextResponse.json(updatedPeriodLog, { status: 200 });
  },
);

export const DELETE = withAuth(
  async (
    _request: NextRequest,
    user: User,
    pb: PocketBase,
    context?: RouteContext,
  ) => {
    // Get ID from route params
    const { id } = await (context?.params ?? Promise.resolve({ id: "" }));

    // Fetch the period log
    let periodLog: PeriodLog;
    try {
      periodLog = await pb.collection("period_logs").getOne<PeriodLog>(id);
    } catch (error) {
      // Handle PocketBase 404 errors (can be Error or plain object)
      const err = error as { status?: number };
      if (err.status === 404) {
        return NextResponse.json(
          { error: "Period log not found" },
          { status: 404 },
        );
      }
      throw error;
    }

    // Check ownership
    if (periodLog.user !== user.id) {
      return NextResponse.json({ error: "Access denied" }, { status: 403 });
    }

    // Delete the period log
    await pb.collection("period_logs").delete(id);

    // Update user.lastPeriodDate to the previous period (or null if no more periods)
    const previousPeriod = await getMostRecentPeriodAfterDeletion(pb, user.id);
    await pb.collection("users").update(user.id, {
      lastPeriodDate: previousPeriod
        ? formatDateStr(new Date(previousPeriod.startDate))
        : null,
    });

    return NextResponse.json({ success: true }, { status: 200 });
  },
);