package response

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

// Envelope wraps API responses in a consistent structure.
type Envelope struct {
	Success bool        `json:"success"`
	Data    interface{} `json:"data,omitempty"`
	Error   *ErrorBody  `json:"error,omitempty"`
	Meta    *Meta       `json:"meta,omitempty"`
}

// ErrorBody represents an error response.
type ErrorBody struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

// Meta holds pagination and other metadata.
type Meta struct {
	Page       int   `json:"page,omitempty"`
	Limit      int   `json:"limit,omitempty"`
	Total      int64 `json:"total,omitempty"`
	TotalPages int   `json:"total_pages,omitempty"`
}

// JSON sends a success response with the given data.
func JSON(w http.ResponseWriter, status int, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(Envelope{
		Success: true,
		Data:    data,
	})
}

// JSONWithMeta sends a success response with data and pagination metadata.
func JSONWithMeta(w http.ResponseWriter, status int, data interface{}, meta *Meta) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(Envelope{
		Success: true,
		Data:    data,
		Meta:    meta,
	})
}

// Error sends an error response.
func Error(w http.ResponseWriter, status int, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(Envelope{
		Success: false,
		Error: &ErrorBody{
			Code:    status,
			Message: message,
		},
	})
}

// NoContent sends a 204 No Content response.
func NoContent(w http.ResponseWriter) {
	w.WriteHeader(http.StatusNoContent)
}