package http

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

// Return an error over an http connection.
// The error will have the given return code `code`
// and a json encoded body with the field "id" set to `errId`
// and a field "message" set to the `message`
//
// Deprecated: Use ProblemDetails or ProblemDetailsStatusOnly instead
func HttpErr(w http.ResponseWriter, errId int, message string, code int) {
	w.WriteHeader(code)
	w.Header().Add("Content-Type", "application/json")
	fmt.Fprintf(w, "{\"id\": %d, \"message\": \"%s\"}", errId, message)
}

// Write an RFC 9457 compliant problem details response
// If details is not nil, it will be included.
// If extras is not nil, each key-value pair will be included at
// the root layer.
// Keys in extras that would overwrite the default elements will be ignored.
// Those would be "type", "status", "title" and "detail"
func ProblemDetails(
	w http.ResponseWriter,
	statusCode int,
	errorType string,
	errorTitle string,
	details *string,
	extras map[string]any,
) {
	w.Header().Add("Content-Type", "application/problem+json")
	w.WriteHeader(statusCode)
	data := map[string]any{
		"type":   errorType,
		"status": statusCode,
		"title":  errorTitle,
	}
	if details != nil {
		data["detail"] = *details
	}
	if extras != nil {
		for k, v := range extras {
			if _, ok := data[k]; ok {
				// Don't overwrite default fields
				continue
			}
			data[k] = v
		}
	}
	enc := json.NewEncoder(w)
	enc.Encode(data)
}

// Write a simple problem details response.
// It only provides the status code, as defined in RFC 9457, section 4.2.1
func ProblemDetailsStatusOnly(w http.ResponseWriter, statusCode int) {
	w.Header().Add("Content-Type", "application/problem+json")
	w.WriteHeader(statusCode)
	data := map[string]any{
		"type":      "about:blank",
		"title":     http.StatusText(statusCode),
		"status":    statusCode,
		"reference": "RFC 9457",
	}

	enc := json.NewEncoder(w)
	enc.Encode(data)
}