interface ITrade {
  id: string;                    // Unique trade ID (UUID)
  type: TradeType;               // "DEPOSIT" or "WITHDRAW"
  status: TradeStatus;           // Current trade status
  game: string;                  // Game app ID ("730" or "252490")

  // Participants
  merchantId: string;            // Your merchant ID
  clientUserId: string;          // Internal client user ID
  clientSteamID: string;         // User's Steam ID 64
  clientTradeUrl: string;        // User's Steam trade URL

  // Items and pricing
  items: InventoryItem[];        // Items in this trade
  totalPrice: number;            // Total value in USD

  // Instant deposit fields (deposits only)
  preCredit?: number;            // Amount credited instantly (USD)
  pendingCredit?: number;        // Amount held until COMPLETED (USD)
  isInstant?: boolean;           // Whether instant credit was requested
  collateral?: {
    merchant: number;            // Merchant collateral portion
    provider: number;            // Provider collateral portion
  };

  // Tracking
  externalId?: string;           // Your tracking ID (from externalId param)
  externalClientUserId?: string; // Your user ID (from clientId param)
  offerID?: string;              // Steam trade offer ID

  // Timing
  holdEndDate?: Date;            // When the 7-day hold expires
  readyAt?: Date;                // When the trade became ready
  createdAt: Date;
  updatedAt: Date;

  // Status-specific
  revertedBy?: RevertedBy;       // Who reversed the trade (if REVERTED)
  error?: string;                // Error message (if FAILED)

  // Bot details
  botInfo?: {
    name: string;
    avatar?: string;
    steamId?: string;
    joined?: Date;
  };
}

interface InventoryItem {
  // Identity
  id: string;                    // Encoded item ID
  appid: number;                 // Game app ID (730 or 252490)
  contextid: number;             // Steam context ID (always 2)

  // Description
  name: string;                  // Display name (e.g. "AK-47 | Redline")
  marketHashName: string;        // Full market name (e.g. "AK-47 | Redline (Field-Tested)")
  type: string;                  // Item type (e.g. "Rifle", "Knife")
  iconUrl: string;               // Steam image hash (use with Steam CDN base URL)

  // Trade state
  tradable: boolean;             // Whether the item can be traded
  accepted?: boolean;            // Whether the item is accepted for deposit (inventory only)
  amount?: number;               // Stack count for Rust items

  // Pricing
  marketPrice?: number;          // BUFF163 market reference price (USD)
  offer?: {
    price: number;               // Actual offer price (USD)
    reference: string;           // Offer reference (pass back in deposit/withdraw)
    delivery?: string;           // "normal" or "auto" (market items only)
    maxAmount?: number;          // Max deposit quantity (inventory only)
  };

  // Cosmetic attributes
  exterior?: string;             // "Factory New", "Minimal Wear", etc.
  rarity?: string;               // "Consumer Grade", "Covert", etc.
  color?: string;                // Rarity color hex (e.g. "#EB4B4B")
  phase?: string;                // Doppler phase (if applicable)
  wear?: string;                 // Float value as string
  fade?: string;                 // Fade percentage (if applicable)
  hardened?: string;             // Case Hardened pattern info
  paintSeed?: number;            // Paint seed number

  // Applied items
  stickers?: Sticker[];          // Applied stickers
  charm?: Charm;                 // Applied charm (CS2 only)

  // Withdrawal-specific
  market?: number;               // Marketplace source (pass in withdraw request)
  purchaseStatus?: ItemPurchaseStatus;  // Per-item purchase progress
}

interface Sticker {
  name: string;                  // Sticker name
  slot: number;                  // Position on the weapon (0-4)
  wear?: number;                 // Sticker wear (0 = perfect, 1 = scraped off)
  iconUrl: string;               // Sticker image URL
}

interface Charm {
  name: string;                  // Charm name
  pattern?: string;              // Pattern type
  iconUrl: string;               // Charm image URL
}

enum TradeStatus {
  INITIATED = 'INITIATED',      // Trade created, processing not started
  PENDING   = 'PENDING',        // Steam trade offer sent
  ACTIVE    = 'ACTIVE',         // Trade offer accepted, transfer in progress
  ESCROW    = 'ESCROW',         // Steam 2FA escrow hold
  HOLD      = 'HOLD',           // 7-day Steam hold period
  COMPLETED = 'COMPLETED',      // Trade finished successfully
  FAILED    = 'FAILED',         // Trade failed
  REVERTED  = 'REVERTED',       // Trade reversed after being active
  PARTIAL   = 'PARTIAL',        // Some items succeeded, others didn't
}

enum TradeType {
  DEPOSIT  = 'DEPOSIT',         // User selling items to merchant
  WITHDRAW = 'WITHDRAW',        // User buying items from market
}

enum RevertedBy {
  SUPPLIER = 'SUPPLIER',        // Marketplace supplier reversed
  USER     = 'USER',            // End user reversed
}

enum ItemPurchaseStatus {
  INITIATED = 'INITIATED',
  PENDING   = 'PENDING',
  ACTIVE    = 'ACTIVE',
  HOLD      = 'HOLD',
  COMPLETED = 'COMPLETED',
  FAILED    = 'FAILED',
  REVERTED  = 'REVERTED',
}

enum Games {
  CS2  = '730',
  RUST = '252490',
}

interface CallbackPayload {
  payload: {
    trade: ITrade;               // Full trade object
    event: string;               // Event name (matches trade status)
    timestamp: string;           // ISO 8601 timestamp
    key: string;                 // HMAC-SHA256 signature
  };
}