export type TaxType = "none" | "cgst_sgst" | "igst";
export type LineMode = "fixed" | "rate";
export type LineUnit = "second" | "minute" | "hour" | "session" | "unit";

export interface Settings {
  vendorName: string;
  vendorAddress: string;
  vendorEmail: string;
  vendorPhone: string;
  vendorPan: string;
  vendorGstin: string;
  vendorStateCode: string;
  logoPath: string | null;
  signaturePath: string | null;
  defaultBankId: number | null;
  defaultTaxRate: number;
  defaultTaxType: TaxType;
  paymentTermsDays: number;
  currency: string;
  onboarded: boolean;
  theme: string;
  gstRegistration: GstRegistration;
  defaultHsnSac: string;
  signatoryName: string;
  signatoryDesignation: string;
  /** The user's default page setup (RenderPrefsV1 JSON); empty means the built-in defaults. */
  renderPrefs: string;
  /** Folder of the last export; kept by the backend (saving settings does not change it). */
  lastExportDir?: string;
}

export interface BankAccount {
  id: number | null;
  label: string;
  bankName: string;
  accountName: string;
  accountNo: string;
  branch: string;
  ifsc: string;
  isDefault: boolean;
}

export interface InvoiceSeries {
  id: number;
  prefix: string;
  padding: number;
  nextNumber: number;
  isActive: boolean;
  createdAt: string;
  nextInvoiceNumber: string;
}

export interface Client {
  id: number | null;
  name: string;
  address: string;
  gstin: string;
  stateCode: string;
  poNumber: string;
  createdAt: string;
}

export interface InvoiceItem {
  id?: number | null;
  description: string;
  mode: LineMode;
  rate: number;
  unit: LineUnit;
  quantity: number;
  amount: number;
  sortOrder: number;
  /** Optional so older callers that build items by hand keep compiling; stored as "" when absent. */
  hsnSac?: string;
}

export type GstRegistration = "unregistered" | "regular";

/** What the webview sends to issue an invoice; totals, tax and words are derived in Rust. */
export interface InvoiceInput {
  invoiceDate: string;
  dueDate: string;
  clientId: number | null;
  clientName: string;
  clientAddress: string;
  clientGstin: string;
  poNumber: string;
  placeOfSupplyStateCode: string;
  discount: number;
  taxType: TaxType;
  taxRate: number;
  reverseCharge: boolean;
  bankAccountId: number | null;
  signaturePath: string | null;
  notes: string;
  saveClient: boolean;
  draftId: number | null;
  items: InvoiceItem[];
}

export type InvoiceStatus = "draft" | "issued" | "cancelled";

/** An invoice as stored: all amounts are derived on the Rust side. */
export interface Invoice {
  id: number;
  number: string;
  seriesId: number | null;
  invoiceDate: string;
  dueDate: string;
  clientId: number | null;
  clientName: string;
  clientAddress: string;
  clientGstin: string;
  poNumber: string;
  placeOfSupplyStateCode: string;
  subtotal: number;
  discount: number;
  taxType: TaxType;
  taxRate: number;
  cgstAmount: number;
  sgstAmount: number;
  igstAmount: number;
  total: number;
  amountInWords: string;
  bankAccountId: number | null;
  bankSnapshot: string;
  signaturePath: string | null;
  notes: string;
  status: InvoiceStatus;
  createdAt: string;
  updatedAt: string;
  docType: "invoice" | "tax_invoice";
  reverseCharge: boolean;
  /** JSON of the supplier details at issue time; empty when unknown. */
  vendorSnapshot: string;
  snapshotOrigin: string;
  cancelledAt: string | null;
  cancelReason: string;
  archivedPdfSha256: string | null;
  /** RenderPrefsV1 JSON frozen at issue; empty when none was stored. */
  renderPrefs: string;
  /** Layout fingerprint of the archived PDF; null when nothing is archived. */
  archivedFingerprint?: string | null;
  archivedAt?: string | null;
  items: InvoiceItem[];
}

export interface DraftSummary {
  id: number;
  updatedAt: string;
  clientName: string | null;
  total: number | null;
}

export interface InvoiceSummary {
  id: number;
  number: string;
  invoiceDate: string;
  dueDate: string;
  clientName: string;
  total: number;
  status: InvoiceStatus;
  createdAt: string;
}

export const EMPTY_ITEM: InvoiceItem = {
  description: "",
  mode: "fixed",
  rate: 0,
  unit: "unit",
  quantity: 1,
  amount: 0,
  sortOrder: 0,
  hsnSac: "",
};

/** GST state codes, same list as STATES in src-tauri/src/gst.rs (from India Compliance). */
export const INDIAN_STATES: { code: string; name: string }[] = [
  { code: "01", name: "Jammu and Kashmir" },
  { code: "02", name: "Himachal Pradesh" },
  { code: "03", name: "Punjab" },
  { code: "04", name: "Chandigarh" },
  { code: "05", name: "Uttarakhand" },
  { code: "06", name: "Haryana" },
  { code: "07", name: "Delhi" },
  { code: "08", name: "Rajasthan" },
  { code: "09", name: "Uttar Pradesh" },
  { code: "10", name: "Bihar" },
  { code: "11", name: "Sikkim" },
  { code: "12", name: "Sampleachal Pradesh" },
  { code: "13", name: "Nagaland" },
  { code: "14", name: "Manipur" },
  { code: "15", name: "Mizoram" },
  { code: "16", name: "Tripura" },
  { code: "17", name: "Meghalaya" },
  { code: "18", name: "Assam" },
  { code: "19", name: "West Bengal" },
  { code: "20", name: "Jharkhand" },
  { code: "21", name: "Odisha" },
  { code: "22", name: "Chhattisgarh" },
  { code: "23", name: "Madhya Pradesh" },
  { code: "24", name: "Gujarat" },
  { code: "26", name: "Dadra and Nagar Haveli and Daman and Diu" },
  { code: "27", name: "Maharashtra" },
  { code: "29", name: "Karnataka" },
  { code: "30", name: "Goa" },
  { code: "31", name: "Lakshadweep Islands" },
  { code: "32", name: "Kerala" },
  { code: "33", name: "Tamil Nadu" },
  { code: "34", name: "Puducherry" },
  { code: "35", name: "Andaman and Nicobar Islands" },
  { code: "36", name: "Telangana" },
  { code: "37", name: "Andhra Pradesh" },
  { code: "38", name: "Ladakh" },
  { code: "96", name: "Other Countries" },
  { code: "97", name: "Other Territory" },
];

export const UNIT_LABELS: Record<LineUnit, string> = {
  second: "per second",
  minute: "per minute",
  hour: "per hour",
  session: "per session",
  unit: "per unit",
};