import { db } from "@/db";
import { submissions } from "@/db/schema";
import {
  and,
  asc,
  count,
  desc,
  eq,
  gte,
  ilike,
  lt,
  or,
  sql,
  type SQL,
} from "drizzle-orm";

export const RESULTS_PAGE_SIZE = 25;

export type ResultFilters = {
  q: string;
  page: number;
  sort: "submittedAt" | "respondent";
  direction: "asc" | "desc";
  edited: "all" | "edited" | "unedited";
  dateFrom: string;
  dateTo: string;
};

export function parseResultFilters(
  params: Record<string, string | string[] | undefined>
): ResultFilters {
  const value = (key: string) => {
    const entry = params[key];
    return Array.isArray(entry) ? entry[0] ?? "" : entry ?? "";
  };
  const page = Number.parseInt(value("page"), 10);
  const sort = value("sort");
  const direction = value("direction");
  const edited = value("edited");

  return {
    q: value("q").trim().slice(0, 100),
    page: Number.isFinite(page) && page > 0 ? page : 1,
    sort: sort === "respondent" ? "respondent" : "submittedAt",
    direction: direction === "asc" ? "asc" : "desc",
    edited:
      edited === "edited" || edited === "unedited" ? edited : "all",
    dateFrom: /^\d{4}-\d{2}-\d{2}$/.test(value("dateFrom"))
      ? value("dateFrom")
      : "",
    dateTo: /^\d{4}-\d{2}-\d{2}$/.test(value("dateTo"))
      ? value("dateTo")
      : "",
  };
}

function bangkokBoundary(date: string, end: boolean) {
  if (!date) return null;
  const value = new Date(`${date}T00:00:00+07:00`);
  if (end) value.setUTCDate(value.getUTCDate() + 1);
  return value;
}

function buildWhere(formId: string, filters: ResultFilters) {
  const conditions: SQL[] = [eq(submissions.formId, formId)];
  if (filters.q) {
    const query = `%${filters.q}%`;
    conditions.push(
      or(
        ilike(submissions.userName, query),
        ilike(submissions.userDiscordId, query)
      )!
    );
  }
  if (filters.edited === "edited") {
    conditions.push(sql`jsonb_array_length(coalesce(${submissions.editHistory}, '[]'::jsonb)) > 0`);
  }
  if (filters.edited === "unedited") {
    conditions.push(sql`jsonb_array_length(coalesce(${submissions.editHistory}, '[]'::jsonb)) = 0`);
  }
  const from = bangkokBoundary(filters.dateFrom, false);
  const to = bangkokBoundary(filters.dateTo, true);
  if (from) conditions.push(gte(submissions.submittedAt, from));
  if (to) conditions.push(lt(submissions.submittedAt, to));
  return and(...conditions)!;
}

export async function getFilteredSubmissions(
  formId: string,
  filters: ResultFilters,
  options: { paginate?: boolean } = {}
) {
  const where = buildWhere(formId, filters);
  const orderDirection = filters.direction === "asc" ? asc : desc;
  const order =
    filters.sort === "respondent"
      ? orderDirection(submissions.userName)
      : orderDirection(submissions.submittedAt);
  const [{ total }] = await db
    .select({ total: count() })
    .from(submissions)
    .where(where);

  const baseQuery = db
    .select()
    .from(submissions)
    .where(where)
    .orderBy(order, orderDirection(submissions.id));
  const rows =
    options.paginate === false
      ? await baseQuery
      : await baseQuery
          .limit(RESULTS_PAGE_SIZE)
          .offset((filters.page - 1) * RESULTS_PAGE_SIZE);

  return { rows, total };
}

export function resultFiltersToSearchParams(
  filters: ResultFilters,
  overrides: Partial<ResultFilters> = {}
) {
  const next = { ...filters, ...overrides };
  const params = new URLSearchParams();
  if (next.q) params.set("q", next.q);
  if (next.page > 1) params.set("page", String(next.page));
  if (next.sort !== "submittedAt") params.set("sort", next.sort);
  if (next.direction !== "desc") params.set("direction", next.direction);
  if (next.edited !== "all") params.set("edited", next.edited);
  if (next.dateFrom) params.set("dateFrom", next.dateFrom);
  if (next.dateTo) params.set("dateTo", next.dateTo);
  return params.toString();
}