// Package api implements the JSON API layer at /api/v1/ for the mobile app.
//
// All handlers return JSON and accept Bearer token auth (or session cookie).
// This package mirrors the same business logic as the HTML handlers but exposes
// it through a structured JSON contract.
package api

import (
	"database/sql"
	"encoding/json"
	"log/slog"
	"net/http"

	"atmoquest/features/auth"
	"atmoquest/internal/apitoken"
	"atmoquest/internal/connection"
	"atmoquest/internal/push"
)

// Handlers holds the shared dependencies for all API endpoints.
type Handlers struct {
	DB        *sql.DB
	Auth      *auth.Handlers
	ConnQueue *connection.Queue
	Tokens    *apitoken.Generator
	Push      *push.Sender
}

// NewHandlers wires the API feature.
func NewHandlers(conn *sql.DB, authH *auth.Handlers, connQueue *connection.Queue, tokens *apitoken.Generator, pusher *push.Sender) *Handlers {
	return &Handlers{DB: conn, Auth: authH, ConnQueue: connQueue, Tokens: tokens, Push: pusher}
}

// --- JSON helpers -----------------------------------------------------------

// writeJSON encodes v as JSON with the given status code.
func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if err := json.NewEncoder(w).Encode(v); err != nil {
		slog.Warn("api: encode response", "err", err)
	}
}

// writeError writes a JSON error response.
func writeError(w http.ResponseWriter, status int, msg string) {
	writeJSON(w, status, map[string]string{"error": msg})
}

// decodeBody reads a JSON request body, capped at 64 KB.
func decodeBody(r *http.Request, v any) error {
	return json.NewDecoder(http.MaxBytesReader(nil, r.Body, 64*1024)).Decode(v)
}