defmodule DaProductAppWeb.AaniController do
  use DaProductAppWeb, :controller
  require Logger

  alias DaProductApp.MerchantRegistration.AaniProvider

  @doc """
  Aani-specific merchant details update endpoint
  
  This endpoint allows updating specific merchant details for merchants
  that have already been onboarded with Aani.
  
  Expected headers:
  - RequestId: Unique request identifier
  - BankUserId: Enrolled BankUserId to modify
  - RequestUserId: Requestor name/ID
  - MerchantTag: Merchant tag received from Aani after onboarding
  - Authorization: Bearer token
  
  Expected payload format:
  {
    "name": "Gold",
    "surname": "Cafe", 
    "denomination": "Iyer-Fyer Co",
    "vatNumber": "HDTBAOY",
    "logo": "data:image/png;base64,..."
  }
  """
  def update_merchant_details(conn, params) do
    Logger.info("Received Aani merchant details update request: #{inspect(params)}")
    
    # Extract required headers
    case extract_required_headers(conn) do
      {:ok, headers} ->
        # Call AaniProvider to handle the update
        case AaniProvider.update_merchant_details(params, headers) do
          {:ok, response} ->
            Logger.info("Aani merchant details update successful: #{inspect(response)}")
            json(conn, %{
              status: "success",
              provider: "aani",
              data: response
            })
          
          {:error, reason} ->
            Logger.error("Aani merchant details update failed: #{inspect(reason)}")
            conn
            |> put_status(:bad_request)
            |> json(%{
              status: "error",
              provider: "aani",
              reason: reason
            })
        end
      
      {:error, missing_headers} ->
        Logger.error("Missing required headers: #{inspect(missing_headers)}")
        conn
        |> put_status(:bad_request)
        |> json(%{
          status: "error",
          code: "MISSING_HEADERS",
          errors: missing_headers
        })
    end
  end

  @doc """
  Generic Aani merchant update endpoint
  
  This endpoint accepts different types of updates based on the "type" parameter:
  - "updateprofile": For updating merchant profile details
  - "mobile": For updating merchant mobile number
  - "mcc": For updating merchant category code
  - Other types can be added as needed
  
  Required params:
  - type: The type of update to perform ("updateprofile", "mobile", "mcc", etc.)
  - Additional params based on the update type
  """
  def update_merchant(conn, params) do
    Logger.info("Received Aani generic update request: #{inspect(params)}")
    
    # Extract the update type
    update_type = Map.get(params, "type")
    
    if is_nil(update_type) do
      Logger.error("Missing required 'type' parameter for Aani update")
      conn
      |> put_status(:bad_request)
      |> json(%{
        status: "error",
        code: "MISSING_TYPE",
        message: "Missing required 'type' parameter. Supported types: updateprofile, mobile, mcc"
      })
    else
      # Extract required headers
      case extract_required_headers(conn) do
        {:ok, headers} ->
          # Call AaniProvider to handle the update
          case AaniProvider.update_merchant(params, headers) do
            {:ok, response} ->
              Logger.info("Aani merchant update successful for type #{update_type}: #{inspect(response)}")
              json(conn, %{
                status: "success",
                provider: "aani",
                type: update_type,
                data: response
              })
            
            {:error, reason} ->
              Logger.error("Aani merchant update failed for type #{update_type}: #{inspect(reason)}")
              conn
              |> put_status(:bad_request)
              |> json(%{
                status: "error",
                provider: "aani",
                type: update_type,
                reason: reason
              })
          end
        
        {:error, missing_headers} ->
          Logger.error("Missing required headers: #{inspect(missing_headers)}")
          conn
          |> put_status(:bad_request)
          |> json(%{
            status: "error",
            code: "MISSING_HEADERS",
            errors: missing_headers
          })
      end
    end
  end

  @doc """
  Aani-specific merchant MCC (Merchant Category Code) update endpoint
  
  This endpoint allows updating the merchant category code for merchants
  that have already been onboarded with Aani.
  
  Expected headers:
  - RequestId: Unique request identifier
  - BankUserId: Enrolled BankUserId to modify
  - RequestUserId: Requestor name/ID
  - MerchantTag: Merchant tag received from Aani after onboarding
  - Authorization: Bearer token
  
  Expected payload format:
  {
    "mcc": "9994"
  }
  """
  def update_merchant_mcc(conn, params) do
    Logger.info("Received Aani merchant MCC update request: #{inspect(params)}")
    
    # Extract required headers
    case extract_required_headers(conn) do
      {:ok, headers} ->
        # Call AaniProvider to handle the MCC update
        case AaniProvider.update_merchant_mcc(params, headers) do
          {:ok, response} ->
            Logger.info("Aani merchant MCC update successful: #{inspect(response)}")
            json(conn, %{
              status: "success",
              provider: "aani",
              data: response
            })
          
          {:error, reason} ->
            Logger.error("Aani merchant MCC update failed: #{inspect(reason)}")
            conn
            |> put_status(:bad_request)
            |> json(%{
              status: "error",
              provider: "aani",
              reason: reason
            })
        end
      
      {:error, missing_headers} ->
        Logger.error("Missing required headers: #{inspect(missing_headers)}")
        conn
        |> put_status(:bad_request)
        |> json(%{
          status: "error",
          code: "MISSING_HEADERS",
          errors: missing_headers
        })
    end
  end

  # Extract and validate required headers
  defp extract_required_headers(conn) do
    required_headers = ["requestid", "bankuserid", "requestuserid", "merchanttag", "authorization"]
    
    headers = Enum.reduce(required_headers, %{}, fn header_name, acc ->
      case get_req_header(conn, header_name) do
        [value | _] -> Map.put(acc, header_name, value)
        [] -> acc
      end
    end)
    
    missing = Enum.filter(required_headers, fn header -> not Map.has_key?(headers, header) end)
    
    if Enum.empty?(missing) do
      {:ok, headers}
    else
      {:error, Enum.map(missing, &"#{&1} header is required")}
    end
  end
end