package api

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

// envelope is the standard API response wrapper.
type envelope struct {
	Success bool   `json:"success"`
	Data    any    `json:"data,omitempty"`
	Error   string `json:"error,omitempty"`
}

// respondJSON writes a JSON success response with the given status code and data.
func respondJSON(w http.ResponseWriter, status int, data any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if err := json.NewEncoder(w).Encode(envelope{Success: true, Data: data}); err != nil {
		log.Printf("[api] encode response: %v", err)
	}
}

// respondError writes a JSON error response with the given status code and message.
func respondError(w http.ResponseWriter, status int, msg string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if err := json.NewEncoder(w).Encode(envelope{Success: false, Error: msg}); err != nil {
		log.Printf("[api] encode error response: %v", err)
	}
}

// respondNotFound writes a 404 JSON error response for the given entity type.
func respondNotFound(w http.ResponseWriter, entity string) {
	respondError(w, http.StatusNotFound, entity+" not found")
}

// decodeJSON reads and decodes the request body into the given value.
// Returns false and writes a 400 error response if decoding fails.
func decodeJSON(w http.ResponseWriter, r *http.Request, v any) bool {
	if err := json.NewDecoder(r.Body).Decode(v); err != nil {
		respondError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return false
	}
	return true
}