/**
 * PB-backed types. Foreign keys are TEXT (we use the related record's `id`
 * and join with expand= at query time). Enum-like fields are TEXT and
 * validated against `DeliveryStatus` / `StatementAction` below.
 */

export type ID = string;

export interface Customer {
  id: ID;
  name: string;
  contact_number?: string;
  email?: string;
  address?: string;
  vat_number?: string;
  created?: string;
  updated?: string;
}

export interface Supplier {
  id: ID;
  name: string;
  contact_number?: string;
  email?: string;
  address?: string;
  vat_number?: string;
  created?: string;
  updated?: string;
}

export type DeliveryStatus = "Pending" | "EFT" | "CASH" | "CARD";
export const DELIVERY_STATUSES: DeliveryStatus[] = [
  "Pending",
  "EFT",
  "CASH",
  "CARD",
];

/** A delivery note is "open" (awaiting payment) when status is Pending. */
export const OPEN_STATUSES: DeliveryStatus[] = ["Pending"];

/** Hard-coded tank / plant options — matches the legacy Flask app. */
export const TANK_OPTIONS = [
  "Tank 2",
  "Tank 3",
  "Tank 4",
  "Bouwser",
  "Tank C",
  "Tank B",
  "RJ BULK",
] as const;
export type TankOption = (typeof TANK_OPTIONS)[number];

export type PricingSource = "special" | "monthly" | "default";
export const PRICING_SOURCES: PricingSource[] = ["special", "monthly", "default"];

/** Customer name used as the "Cash Customers" placeholder filter. */
export const CASH_CUSTOMER_NAME = "Cash Customers";

export interface DeliveryNote {
  id: ID;
  number: string;
  date: string;
  /** FK -> customers.id */
  customer: ID;
  vehicle_registration?: string;
  qty_litres_supplied: number;
  plant_dispensing?: string;
  status?: DeliveryStatus | "";
  /** Legacy status from the SQLite dump (Statement Viewed, Invoiced, etc.) — preserved for reference. */
  old_status?: string;
  price_per_litre?: number;
  total_value?: number;
  pricing_source?: PricingSource | "";
  created?: string;
  updated?: string;
  /** When fetched with `expand=customer`, the customer record is here. */
  expand?: { customer?: Customer };
}

export interface FuelPurchase {
  id: ID;
  /** FK -> suppliers.id */
  supplier: ID;
  purchase_qty: number;
  purchase_price: number;
  purchase_date: string;
  created?: string;
  updated?: string;
  expand?: { supplier?: Supplier };
}

export interface CustomerPricing {
  id: ID;
  /** FK -> customers.id */
  customer: ID;
  year: number;
  month: number; // 1-12
  price_per_litre: number;
  special_price?: number;
  /** FK -> users.id */
  created_by?: ID;
  created?: string;
  updated?: string;
  expand?: { customer?: Customer };
}

export interface MonthlyPriceIncrease {
  id: ID;
  year: number;
  month: number;
  /** Actually stores cent amount. */
  percentage_increase: number;
  /** FK -> users.id */
  applied_by?: ID;
  created?: string;
  updated?: string;
}

export interface FuelSettings {
  id: ID;
  default_price_per_litre: number;
  statement_cc_email?: string;
  statement_from_email?: string;
  statement_email_password?: string;
  statement_app_email?: string;
}

export type StatementAction = "Email Sent" | "Preview Generated";
export const STATEMENT_ACTIONS: StatementAction[] = ["Email Sent", "Preview Generated"];

export interface StatementLogEntry {
  id: ID;
  action: StatementAction;
  details?: string;
  /** FK -> users.id */
  actor?: ID;
  created?: string;
  updated?: string;
}

export interface AppUser {
  id: ID;
  email: string;
  name?: string;
  verified?: boolean;
}