defmodule CCXT.WS.Config do
  @moduledoc """
  Per-exchange WebSocket configuration.

  T94 ships WS configuration for the priority-tier universe using the extended
  shape that routes WS subscription patterns (`CCXT.WS.Subscription`) and WS
  auth patterns (`CCXT.WS.Auth`). Replaces T92's 3-canary
  `subscribe_builder: {mod, fun}` with `subscription_pattern` + `auth_pattern`
  dispatch atoms.

  **Count:** 13 exchanges — every entry here has a matching `CCXT.Registry`
  module. T102 (2026-04-19) removed three orphan entries (`bingx`, `bitget`,
  `mexc`) whose `Registry` lookups raised because no spec file exists for them
  under the current tier1/tier2/dex scope. Add them back via
  `mix ccxt_extract.update --exchange <id>` + a re-register in Registry before
  reinstating their config here.

  WS URLs currently live in this consumer-side map because JSON specs don't
  yet surface a clean `urls.api.ws` field. A follow-up ccxt_extract task will
  emit `urls.api.ws.{public,private,sandbox_public,sandbox_private}` from the
  JS AST; when it lands, this module can be replaced by a one-line read from
  `exchange.spec["urls"]["api"]["ws"]`. (Prior to schema 3.0.0 the raw AST was
  available under `structure.ws_methods`; T117 dropped that payload to fit the
  Hex size cap — the upstream WS-URL task supersedes that path.)

  ## Entry shape

      %{
        public_url: String.t() | nil,           # may contain `{hostname}` placeholder; nil = requires REST pre-call
        public_url_sandbox: String.t() | nil,
        private_url: String.t() | nil,
        private_url_sandbox: String.t() | nil,
        heartbeat: %{type: :ping | :deribit | :custom, interval: pos_integer() | nil},
        subscription_pattern: atom(),           # routed via CCXT.WS.Subscription
        subscription_config: map(),
        auth_pattern: atom() | nil,             # routed via CCXT.WS.Auth; nil = public-only wiring
        auth_config: map()
      }

  ## Known URL limitations (MVP — single URL per public/private slot)

  Several exchanges expose per-product URLs (spot vs linear/inverse swap vs
  option). The current shape captures one representative URL per
  `{section, sandbox}` slot; product routing will land in a follow-up task
  once the adapter layer needs it.

  - `bybit`  — linear-only (`/v5/public/linear`). spot/inverse/option need routing.
  - `binance` — spot-only. USDⓈ-M futures (`fstream.binance.com`), COIN-M
    (`dstream.binance.com`), and portfolio margin (`/pm/ws`) need routing.
  - `htx` / `huobi` — spot-only (`api.huobi.pro/ws`). Contract/swap endpoints
    live on `api.hbdm.vn`.
  - `aster` — spot-only. Swap on `fstream.asterdex.com`.
  - `kucoin` — URLs are fully dynamic (REST `POST /api/v1/bullet-{public,private}`
    returns the WSS host + token). Recorded as `nil` until the adapter layer
    wires the pre-call.
  """

  @configs %{
    "binance" => %{
      public_url: "wss://stream.binance.com:9443/ws",
      public_url_sandbox: "wss://stream.testnet.binance.vision/ws",
      private_url: "wss://stream.binance.com:9443/ws",
      private_url_sandbox: "wss://stream.testnet.binance.vision/ws",
      heartbeat: %{type: :ping, interval: 180_000},
      subscription_pattern: :method_subscribe,
      subscription_config: %{separator: "@", market_id_format: :lowercase},
      auth_pattern: :listen_key,
      auth_config: %{
        pre_auth: %{
          type: :listen_key,
          endpoints: %{
            spot: "privatePostUserDataStream",
            linear: "fapiPrivatePostListenKey",
            inverse: "dapiPrivatePostListenKey"
          }
        }
      }
    },
    "bybit" => %{
      public_url: "wss://stream.{hostname}/v5/public/linear",
      public_url_sandbox: "wss://stream-testnet.{hostname}/v5/public/linear",
      private_url: "wss://stream.{hostname}/v5/private",
      private_url_sandbox: "wss://stream-testnet.{hostname}/v5/private",
      heartbeat: %{type: :ping, interval: 20_000},
      subscription_pattern: :op_subscribe,
      subscription_config: %{separator: "."},
      auth_pattern: :direct_hmac_expiry,
      auth_config: %{
        op_field: "op",
        op_value: "auth",
        encoding: :hex,
        expires_offset_ms: 10_000
      }
    },
    "okx" => %{
      public_url: "wss://ws.okx.com:8443/ws/v5/public",
      public_url_sandbox: "wss://wspap.okx.com:8443/ws/v5/public",
      private_url: "wss://ws.okx.com:8443/ws/v5/private",
      private_url_sandbox: "wss://wspap.okx.com:8443/ws/v5/private",
      heartbeat: %{type: :ping, interval: 25_000},
      subscription_pattern: :op_subscribe_objects,
      subscription_config: %{},
      auth_pattern: :iso_passphrase,
      auth_config: %{timestamp_unit: :seconds}
    },
    "deribit" => %{
      public_url: "wss://www.deribit.com/ws/api/v2",
      public_url_sandbox: "wss://test.deribit.com/ws/api/v2",
      private_url: "wss://www.deribit.com/ws/api/v2",
      private_url_sandbox: "wss://test.deribit.com/ws/api/v2",
      heartbeat: %{type: :deribit, interval: 30_000},
      subscription_pattern: :jsonrpc_subscribe,
      subscription_config: %{method: "public/subscribe"},
      auth_pattern: :jsonrpc_linebreak,
      auth_config: %{}
    },
    "kraken" => %{
      public_url: "wss://ws.kraken.com/v2",
      public_url_sandbox: "wss://beta-ws.kraken.com/v2",
      private_url: "wss://ws-auth.kraken.com/v2",
      private_url_sandbox: "wss://beta-ws-auth.kraken.com/v2",
      heartbeat: %{type: :ping, interval: 60_000},
      subscription_pattern: :method_params_subscribe,
      subscription_config: %{},
      auth_pattern: :rest_token,
      auth_config: %{
        pre_auth: %{
          type: :rest_token,
          endpoint: "privatePostGetWebSocketsToken"
        }
      }
    },
    "kucoin" => %{
      # URLs are acquired via REST POST /api/v1/bullet-{public,private}.
      # Left nil until the adapter layer wires the pre-call.
      public_url: nil,
      public_url_sandbox: nil,
      private_url: nil,
      private_url_sandbox: nil,
      heartbeat: %{type: :ping, interval: 18_000},
      subscription_pattern: :type_subscribe,
      subscription_config: %{op_field: "type", args_field: "topic", args_format: :string},
      auth_pattern: :iso_passphrase,
      auth_config: %{timestamp_unit: :milliseconds}
    },
    "gate" => %{
      public_url: "wss://api.gateio.ws/ws/v4/",
      public_url_sandbox: nil,
      private_url: "wss://api.gateio.ws/ws/v4/",
      private_url_sandbox: nil,
      heartbeat: %{type: :ping, interval: 30_000},
      subscription_pattern: :event_subscribe,
      subscription_config: %{args_format: :object_list},
      auth_pattern: :sha512_newline,
      auth_config: %{}
    },
    "htx" => %{
      public_url: "wss://api.huobi.pro/ws",
      public_url_sandbox: nil,
      private_url: "wss://api.huobi.pro/ws/v2",
      private_url_sandbox: nil,
      heartbeat: %{type: :custom, interval: 20_000},
      subscription_pattern: :sub_subscribe,
      subscription_config: %{separator: "."},
      auth_pattern: :direct_hmac_expiry,
      auth_config: %{
        op_field: "op",
        op_value: "auth",
        encoding: :base64,
        expires_offset_ms: 10_000
      }
    },
    "huobi" => %{
      public_url: "wss://api.huobi.pro/ws",
      public_url_sandbox: nil,
      private_url: "wss://api.huobi.pro/ws/v2",
      private_url_sandbox: nil,
      heartbeat: %{type: :custom, interval: 20_000},
      subscription_pattern: :sub_subscribe,
      subscription_config: %{separator: "."},
      auth_pattern: :direct_hmac_expiry,
      auth_config: %{
        op_field: "op",
        op_value: "auth",
        encoding: :base64,
        expires_offset_ms: 10_000
      }
    },
    "bitmex" => %{
      public_url: "wss://ws.bitmex.com/realtime",
      public_url_sandbox: "wss://ws.testnet.bitmex.com/realtime",
      private_url: "wss://ws.bitmex.com/realtime",
      private_url_sandbox: "wss://ws.testnet.bitmex.com/realtime",
      heartbeat: %{type: :ping, interval: 30_000},
      subscription_pattern: :op_subscribe,
      subscription_config: %{separator: "."},
      auth_pattern: :direct_hmac_expiry,
      auth_config: %{
        op_field: "op",
        op_value: "authKeyExpires",
        encoding: :base64,
        expires_offset_ms: 10_000
      }
    },
    "bitfinex" => %{
      public_url: "wss://api-pub.bitfinex.com/ws/2",
      public_url_sandbox: nil,
      private_url: "wss://api.bitfinex.com/ws/2",
      private_url_sandbox: nil,
      heartbeat: %{type: :ping, interval: 30_000},
      subscription_pattern: :event_subscribe,
      subscription_config: %{op_field: "event", args_field: "channel", args_format: :string},
      auth_pattern: :sha384_nonce,
      auth_config: %{}
    },
    "coinbaseexchange" => %{
      public_url: "wss://ws-feed.exchange.coinbase.com",
      public_url_sandbox: "wss://ws-feed-public.sandbox.exchange.coinbase.com",
      private_url: "wss://ws-feed.exchange.coinbase.com",
      private_url_sandbox: "wss://ws-feed-public.sandbox.exchange.coinbase.com",
      heartbeat: %{type: :ping, interval: 30_000},
      subscription_pattern: :type_subscribe,
      subscription_config: %{
        op_field: "type",
        args_field: "product_ids",
        args_format: :string_list,
        channels_field: "channels"
      },
      auth_pattern: :inline_subscribe,
      auth_config: %{}
    },
    "aster" => %{
      public_url: "wss://sstream.asterdex.com/ws",
      public_url_sandbox: nil,
      private_url: "wss://sstream.asterdex.com/ws",
      private_url_sandbox: nil,
      heartbeat: %{type: :ping, interval: 180_000},
      subscription_pattern: :method_subscribe,
      subscription_config: %{separator: "@", market_id_format: :lowercase},
      auth_pattern: :listen_key,
      auth_config: %{
        pre_auth: %{
          type: :listen_key,
          endpoints: %{spot: "privatePostUserDataStream"}
        }
      }
    }
  }

  @doc "Returns the WS config map for the given exchange id, or nil if unsupported."
  @spec for_exchange(String.t()) :: map() | nil
  def for_exchange(id) when is_binary(id), do: Map.get(@configs, id)

  @doc "Returns true if this exchange has a WS config entry."
  @spec supported?(String.t()) :: boolean()
  def supported?(id) when is_binary(id), do: Map.has_key?(@configs, id)

  @doc "Returns all supported exchange ids."
  @spec supported_exchanges() :: [String.t()]
  def supported_exchanges, do: Map.keys(@configs)
end