import { NextResponse } from "next/server";
import { requireSessionUser } from "@/lib/server/session";
import { createSchedule, listSchedules, requireActiveGroup } from "@/lib/server/schedules";
import { toErrorResponse } from "@/lib/server/errors";
import { getRequestMeta } from "@/lib/server/request";

function parseTags(value: unknown) {
    if (Array.isArray(value)) return value.map(tag => String(tag));
    if (typeof value === "string") return value.split(",");
    return [] as string[];
}

export async function GET() {
    const { requestId } = await getRequestMeta();
    try {
        const user = await requireSessionUser();
        const groupId = await requireActiveGroup(user.id);
        const schedules = await listSchedules(groupId);
        return NextResponse.json({ requestId, request_id: requestId, schedules });
    } catch (e) {
        const { status, body } = toErrorResponse(e, "GET /api/schedules", requestId);
        return NextResponse.json(body, { status });
    }
}

export async function POST(req: Request) {
    const { requestId } = await getRequestMeta();
    try {
        const user = await requireSessionUser();
        const groupId = await requireActiveGroup(user.id);
        const body = await req.json().catch(() => null);
        const amountDollars = Number(body?.amountDollars || 0);
        const startsOn = String(body?.startsOn || "");
        const necessity = String(body?.necessity || "");
        const tags = parseTags(body?.tags);
        const purchaseType = String(body?.purchaseType || tags[0] || "General").trim();
        const notes = String(body?.notes || "").trim();
        const entryType = String(body?.entryType || "SPENDING").toUpperCase();
        const frequency = String(body?.frequency || "").toUpperCase();
        const intervalCount = Number(body?.intervalCount || 1);
        const endCondition = body?.endCondition ? String(body.endCondition).toUpperCase() : "NEVER";
        const endCount = body?.endCount != null ? Number(body.endCount) : null;
        const endDate = body?.endDate ? String(body.endDate) : null;
        const createEntryNow = Boolean(body?.createEntryNow);

        if (!Number.isFinite(amountDollars) || amountDollars <= 0)
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_AMOUNT", message: "Invalid amount" } }, { status: 400 });
        if (!startsOn) return NextResponse.json({ requestId, request_id: requestId, error: { code: "MISSING_STARTS_ON", message: "startsOn is required" } }, { status: 400 });
        if (!purchaseType) return NextResponse.json({ requestId, request_id: requestId, error: { code: "MISSING_PURCHASE_TYPE", message: "purchaseType is required" } }, { status: 400 });
        if (!['NECESSARY', 'BOTH', 'UNNECESSARY'].includes(necessity))
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_NECESSITY", message: "Invalid necessity" } }, { status: 400 });
        if (!['SPENDING', 'INCOME'].includes(entryType))
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_ENTRY_TYPE", message: "Invalid entryType" } }, { status: 400 });
        if (!['DAILY', 'WEEKLY', 'MONTHLY', 'YEARLY'].includes(frequency))
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_FREQUENCY", message: "Invalid frequency" } }, { status: 400 });
        if (!Number.isFinite(intervalCount) || intervalCount <= 0)
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_INTERVAL", message: "Invalid intervalCount" } }, { status: 400 });
        if (!['NEVER', 'AFTER_COUNT', 'BY_DATE'].includes(endCondition))
            return NextResponse.json({ requestId, request_id: requestId, error: { code: "INVALID_END_CONDITION", message: "Invalid endCondition" } }, { status: 400 });

        const schedule = await createSchedule({
            groupId,
            userId: user.id,
            entryType: entryType as "SPENDING" | "INCOME",
            amountDollars,
            startsOn,
            necessity: necessity as "NECESSARY" | "BOTH" | "UNNECESSARY",
            purchaseType,
            notes: notes || undefined,
            tags,
            frequency: frequency as "DAILY" | "WEEKLY" | "MONTHLY" | "YEARLY",
            intervalCount,
            endCondition: endCondition as "NEVER" | "AFTER_COUNT" | "BY_DATE",
            endCount,
            endDate,
            createEntryNow
        });

        return NextResponse.json({ requestId, request_id: requestId, schedule });
    } catch (e) {
        const { status, body } = toErrorResponse(e, "POST /api/schedules", requestId);
        return NextResponse.json(body, { status });
    }
}