import { IsString, IsDateString, IsOptional, IsEnum, IsInt, Min, Max } from 'class-validator';
import { Type } from 'class-transformer';
import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
import { PaymentMethodType } from '@prisma/client';
import { SeatBlockReasonCategory } from '../seats/seats.dto';

export enum ReportType {
  REVENUE = 'REVENUE',
  OCCUPANCY = 'OCCUPANCY',
  AGENT_SALES = 'AGENT_SALES',
  CANCELLATIONS = 'CANCELLATIONS',
  PAYMENT_METHODS = 'PAYMENT_METHODS'
}

export enum ExportFormat {
  JSON = 'JSON',
  CSV = 'CSV',
  PDF = 'PDF'
}

export class GenerateReportDto {
  @ApiProperty({ enum: ReportType }) @IsEnum(ReportType) reportType: ReportType;
  @ApiProperty({ example: '2026-01-01' }) @IsDateString() dateFrom: string;
  @ApiProperty({ example: '2026-01-31' }) @IsDateString() dateTo: string;
  @ApiPropertyOptional() @IsOptional() @IsString() routeId?: string;
  @ApiPropertyOptional() @IsOptional() @IsString() agentId?: string;
}

export class ExportReportDto {
  @ApiProperty() @IsString() reportId: string;
  @ApiProperty({ enum: ExportFormat }) @IsEnum(ExportFormat) format: ExportFormat;
}

// ── Blocked Seat Revenue Loss ────────────────────────────────────────────────

export enum BlockedSeatsLossSortBy {
  /** Largest estimated loss first (default). */
  LOSS_DESC = 'lossMinor',
  /** Smallest estimated loss first. */
  LOSS_ASC = 'lossMinorAsc',
  /** Most blocked seats first. */
  BLOCKED_SEATS = 'blockedSeatCount',
  /** Soonest departure first. */
  DEPARTURE = 'departureAt',
}

export class BlockedSeatsRevenueLossQueryDto {
  @ApiPropertyOptional({
    example: '2026-07-01',
    description: 'Start of the window, inclusive, matched on TrainSchedule.departureAt. Defaults to the earliest scheduled departure on record.',
  })
  @IsOptional() @IsDateString() dateFrom?: string;

  @ApiPropertyOptional({
    example: '2026-07-31',
    description: 'End of the window, inclusive, matched on TrainSchedule.departureAt. Defaults to the latest scheduled departure on record.',
  })
  @IsOptional() @IsDateString() dateTo?: string;

  @ApiPropertyOptional({ description: 'Restrict to a single TrainSchedule.' })
  @IsOptional() @IsString() scheduleId?: string;

  @ApiPropertyOptional({ description: 'Restrict to schedules running this route.' })
  @IsOptional() @IsString() routeId?: string;

  @ApiPropertyOptional({ description: 'Restrict to schedules operated by this train.' })
  @IsOptional() @IsString() trainId?: string;

  @ApiPropertyOptional({
    description:
      'Restrict to blocks on seats in this coach. Load factor still reflects the whole train, so the percentage stays comparable.',
  })
  @IsOptional() @IsString() coachId?: string;

  @ApiPropertyOptional({
    enum: SeatBlockReasonCategory,
    description: 'Restrict to blocks in this reporting bucket. Legacy uncategorized blocks are excluded when set.',
  })
  @IsOptional() @IsEnum(SeatBlockReasonCategory) reasonCategory?: SeatBlockReasonCategory;

  @ApiPropertyOptional({
    description: "Blocker filter — matches the IAM user id exactly, or the recorded name case-insensitively.",
  })
  @IsOptional() @IsString() blockedBy?: string;

  @ApiPropertyOptional({
    example: 'Ethiopian',
    default: 'Ethiopian',
    description:
      'Nationality the counterfactual fares are priced at. Drives both the seat-class tariff variant (LOCAL vs INTERNATIONAL) and the billing currency. Defaults to Ethiopian — the local tariff in ETB.',
  })
  @IsOptional() @IsString() nationality?: string;

  @ApiPropertyOptional({ default: 1, minimum: 1, description: 'Page of schedules, 1-based.' })
  @IsOptional() @Type(() => Number) @IsInt() @Min(1) page?: number;

  @ApiPropertyOptional({ default: 25, minimum: 1, maximum: 200, description: 'Schedules per page.' })
  @IsOptional() @Type(() => Number) @IsInt() @Min(1) @Max(200) pageSize?: number;

  @ApiPropertyOptional({
    enum: BlockedSeatsLossSortBy,
    default: BlockedSeatsLossSortBy.LOSS_DESC,
    description: 'Schedule ordering. Defaults to largest estimated loss first.',
  })
  @IsOptional() @IsEnum(BlockedSeatsLossSortBy) sortBy?: BlockedSeatsLossSortBy;
}

// ── Finance Summary ──────────────────────────────────────────────────────────

export enum FinanceGranularity {
  DAILY = 'daily',
  WEEKLY = 'weekly',
  MONTHLY = 'monthly',
}

/**
 * Domestic vs cross-border traffic, derived from the endpoints' `Station.countryCode`:
 * a trip is INTERCITY only when both endpoints sit in Ethiopia, and INTERNATIONAL as soon
 * as either endpoint is outside it — which on this line means Djibouti (Alisabieh, Holhol,
 * Nagad). A trip wholly inside Djibouti counts as INTERNATIONAL too.
 */
export enum FinanceTripType {
  INTERCITY = 'intercity',
  INTERNATIONAL = 'international',
}

/**
 * Travel-package revenue vs ordinary ticket sales, derived from `Booking.packageId`.
 * NOT the `Booking.bookingType` column, which holds ONE_WAY / ROUND_TRIP — every package
 * booking happens to be ROUND_TRIP, but that is a different question from this one.
 */
export enum FinanceBookingType {
  REGULAR = 'regular',
  PACKAGE = 'package',
}

/**
 * Which revenue stream a row came from. `ticket` is the booking fare — all this report used to
 * count. The rest are fees collected after the fare: `excess_baggage` from ExcessBaggageCharge,
 * `outstanding` from a PAID SupplementaryCharge with reason UNDERPAYMENT, and `other` from every
 * remaining supplementary reason (UPGRADE, RESCHEDULE, and anything added later — `reason` is a
 * free-text column, so this bucket is deliberately open-ended).
 */
export enum FinanceRevenueType {
  TICKET = 'ticket',
  EXCESS_BAGGAGE = 'excess_baggage',
  OUTSTANDING = 'outstanding',
  OTHER = 'other',
}

export class FinanceSummaryQueryDto {
  @ApiProperty({ example: '2026-07-01', description: 'Start of the window, inclusive, matched on PaymentIntent.paidAt.' })
  @IsDateString() dateFrom: string;

  @ApiProperty({ example: '2026-07-31', description: 'End of the window, inclusive, matched on PaymentIntent.paidAt.' })
  @IsDateString() dateTo: string;

  @ApiPropertyOptional({ enum: FinanceGranularity, default: FinanceGranularity.DAILY })
  @IsOptional() @IsEnum(FinanceGranularity) granularity?: FinanceGranularity;

  @ApiPropertyOptional({ description: 'Restrict to bookings departing from this station.' })
  @IsOptional() @IsString() originStationId?: string;

  @ApiPropertyOptional({ description: 'Restrict to bookings arriving at this station.' })
  @IsOptional() @IsString() destinationStationId?: string;

  @ApiPropertyOptional({ enum: PaymentMethodType, description: 'Restrict to payments made with this method.' })
  @IsOptional() @IsEnum(PaymentMethodType) method?: PaymentMethodType;

  @ApiPropertyOptional({
    enum: FinanceTripType,
    description:
      'Restrict to trips wholly inside Ethiopia (intercity) or trips touching a station outside ' +
      'Ethiopia (international — in practice Djibouti). Omit for all trips.',
  })
  @IsOptional() @IsEnum(FinanceTripType) tripType?: FinanceTripType;

  @ApiPropertyOptional({
    enum: FinanceBookingType,
    description:
      'Restrict to ordinary ticket sales (regular) or travel-package bookings (package). ' +
      'Omit for all bookings. Unrelated to the ONE_WAY/ROUND_TRIP booking type.',
  })
  @IsOptional() @IsEnum(FinanceBookingType) bookingType?: FinanceBookingType;

  @ApiPropertyOptional({
    enum: FinanceRevenueType,
    description:
      'Restrict to one revenue stream: the booking fare (ticket), excess-baggage fees ' +
      '(excess_baggage), recovered underpayments (outstanding), or every other supplementary ' +
      'charge such as upgrades and reschedules (other). Omit for all revenue.',
  })
  @IsOptional() @IsEnum(FinanceRevenueType) revenueType?: FinanceRevenueType;
}