package httpapi

import (
	"encoding/json"
	"net/http"
)

type responseEnvelope struct {
	RequestID string `json:"request_id"`
	Data      any    `json:"data,omitempty"`
	Error     *Error `json:"error,omitempty"`
}

type Error struct {
	Code        string         `json:"code"`
	Message     string         `json:"message"`
	Retryable   bool           `json:"retryable"`
	FieldErrors []FieldError   `json:"field_errors"`
	Details     map[string]any `json:"details"`
}

type FieldError struct {
	Field   string `json:"field"`
	Message string `json:"message"`
}

func WriteJSON(writer http.ResponseWriter, request *http.Request, status int, data any) {
	write(writer, status, responseEnvelope{RequestID: RequestID(request.Context()), Data: data})
}

func WriteError(writer http.ResponseWriter, request *http.Request, status int, code, message string) {
	WriteAPIError(writer, request, status, Error{
		Code: code, Message: message, Retryable: false,
		FieldErrors: []FieldError{}, Details: map[string]any{},
	})
}

func WriteAPIError(writer http.ResponseWriter, request *http.Request, status int, apiError Error) {
	if apiError.FieldErrors == nil {
		apiError.FieldErrors = []FieldError{}
	}
	if apiError.Details == nil {
		apiError.Details = map[string]any{}
	}
	write(writer, status, responseEnvelope{
		RequestID: RequestID(request.Context()),
		Error:     &apiError,
	})
}

func write(writer http.ResponseWriter, status int, body responseEnvelope) {
	writer.Header().Set("Content-Type", "application/json; charset=utf-8")
	writer.WriteHeader(status)
	_ = json.NewEncoder(writer).Encode(body)
}