import { model, models, Schema, type InferSchemaType, type Model } from "mongoose";
import { FREQUENCIES, MONTHLY_MODES } from "@/shared/recurrence";
import { TRANSACTION_TYPES } from "@/shared/transactions";

/**
 * Düzenli işlem kuralı (Bölüm 6.7). Her tekrar için `planned` durumunda bir işlem üretilir
 * (`transactions.recurringRuleId` + `occurrenceIndex`, benzersiz). Bitiş tarihsiz kurallarda
 * ufuk 12 ay; okuma sırasında ilerletilir.
 */
const recurringRuleSchema = new Schema(
  {
    householdId: { type: Schema.Types.ObjectId, required: true },
    // İşlem şablonu (bölme yok).
    type: { type: String, enum: TRANSACTION_TYPES, required: true },
    amountMinor: { type: Number, required: true, min: 1 },
    /** Tutar tahmini mi (ör. fatura)? Onaylarken düzeltilir. */
    isEstimate: { type: Boolean, default: false },
    accountId: { type: Schema.Types.ObjectId, required: true },
    toAccountId: { type: Schema.Types.ObjectId, default: null },
    categoryId: { type: Schema.Types.ObjectId, default: null },
    payeeName: { type: String, default: "", maxlength: 80 },
    description: { type: String, default: "", maxlength: 500 },
    tags: { type: [String], default: [] },
    // Tekrar.
    frequency: { type: String, enum: FREQUENCIES, required: true },
    interval: { type: Number, default: 1, min: 1, max: 12 },
    monthlyMode: { type: String, enum: MONTHLY_MODES, default: "day" },
    /** "YYYY-MM-DD" (İstanbul günü). */
    startDate: { type: String, required: true },
    endDate: { type: String, default: null },
    count: { type: Number, default: null, min: 1 },
    /** Üretilen son ufuk ("YYYY-MM-DD"); null → hiç üretilmedi. */
    generatedUntil: { type: String, default: null },
    deletedAt: { type: Date, default: null },
    seedRef: { type: String, default: null },
    createdBy: { type: Schema.Types.ObjectId, required: true },
    updatedBy: { type: Schema.Types.ObjectId, required: true },
  },
  { timestamps: true, collection: "recurringRules" },
);

recurringRuleSchema.index({ householdId: 1, deletedAt: 1, generatedUntil: 1 });
recurringRuleSchema.index(
  { householdId: 1, seedRef: 1 },
  { unique: true, partialFilterExpression: { seedRef: { $type: "string" } } },
);

export type RecurringRule = InferSchemaType<typeof recurringRuleSchema>;

export const RecurringRuleModel: Model<RecurringRule> =
  (models.RecurringRule as Model<RecurringRule> | undefined) ??
  model<RecurringRule>("RecurringRule", recurringRuleSchema);