import { Connection, Query, Schema } from "mongoose";

const PERSIAN_TO_ENGLISH: Record<string, string> = {
  "۰": "0",
  "۱": "1",
  "۲": "2",
  "۳": "3",
  "۴": "4",
  "۵": "5",
  "۶": "6",
  "۷": "7",
  "۸": "8",
  "۹": "9",
};

function normalizeDigits(value: string): string {
  return value.replace(/[۰-۹]/g, (ch) => PERSIAN_TO_ENGLISH[ch] ?? ch);
}

function toIranFaDateTimeTuple(input: Date): [string, string] {
  const dateFa = normalizeDigits(
    input.toLocaleDateString("fa-IR", {
      timeZone: "Asia/Tehran",
      year: "numeric",
      month: "2-digit",
      day: "2-digit",
    }),
  );
  const timeFa = normalizeDigits(
    input.toLocaleTimeString("fa-IR", {
      timeZone: "Asia/Tehran",
      hour12: false,
      hour: "2-digit",
      minute: "2-digit",
      second: "2-digit",
    }),
  );
  return [dateFa, timeFa];
}

function isMissingFaTuple(value: unknown): boolean {
  if (value == null) return true;
  if (!Array.isArray(value)) return false;
  if (value.length < 2) return true;
  const [d, t] = value;
  return !d || !t;
}

function writeFaTimestampsOnUpdate(query: Query<any, any>): void {
  const nowFa = toIranFaDateTimeTuple(new Date());
  const update = (query.getUpdate() ?? {}) as Record<string, any>;

  if (!update.$set || typeof update.$set !== "object") {
    update.$set = {};
  }

  update.$set.updatedAtFa = nowFa;

  // Keep createdAtFa immutable on regular updates; set only for upsert inserts.
  const opts = (query as any).getOptions?.() ?? {};
  if (opts.upsert) {
    if (!update.$setOnInsert || typeof update.$setOnInsert !== "object") {
      update.$setOnInsert = {};
    }
    if (isMissingFaTuple(update.$setOnInsert.createdAtFa)) {
      update.$setOnInsert.createdAtFa = nowFa;
    }
  }

  query.setUpdate(update);
}

/**
 * Adds `createdAtFa` / `updatedAtFa` (Iran timezone tuple: [date, time])
 * to all schemas that use mongoose timestamps.
 */
export function applyIranFaTimestampPlugin(connection: Connection): void {
  connection.plugin((schema: Schema) => {
    const timestamps = schema.get("timestamps");
    if (!timestamps) return;

    schema.add({
      createdAtFa: { type: [String], index: true },
      updatedAtFa: { type: [String], index: true },
    });

    schema.pre("save", function (next) {
      const nowFa = toIranFaDateTimeTuple(new Date());
      if (isMissingFaTuple((this as any).createdAtFa)) {
        (this as any).createdAtFa = nowFa;
      }
      (this as any).updatedAtFa = nowFa;
      next();
    });

    schema.pre("insertMany", function (next, docs: any[]) {
      const nowFa = toIranFaDateTimeTuple(new Date());
      for (const doc of docs) {
        if (isMissingFaTuple(doc.createdAtFa)) doc.createdAtFa = nowFa;
        doc.updatedAtFa = nowFa;
      }
      next();
    });

    schema.pre("findOneAndUpdate", function () {
      writeFaTimestampsOnUpdate(this);
    });
    schema.pre("updateOne", function () {
      writeFaTimestampsOnUpdate(this);
    });
    schema.pre("updateMany", function () {
      writeFaTimestampsOnUpdate(this);
    });
  });
}