// Package httpapi serves the Kamado REST API. WebSocket push and static
// UI serving land in a follow-up commit.
package httpapi

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

	"github.com/kamadopool/kamado-api/internal/state"
)

type Server struct {
	Agg *state.Aggregator
	Hub *Hub
	Log *slog.Logger
}

func New(agg *state.Aggregator, log *slog.Logger) *Server {
	return &Server{Agg: agg, Hub: NewHub(), Log: log}
}

// Handler returns an http.Handler with all kamado routes mounted under /api.
func (s *Server) Handler() http.Handler {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /api/health", s.health)
	mux.HandleFunc("GET /api/pool", s.pool)
	mux.HandleFunc("GET /api/users", s.users)
	mux.HandleFunc("GET /api/workers", s.workers)
	mux.HandleFunc("GET /api/clients", s.clients)
	mux.HandleFunc("GET /api/blocks", s.blocks)
	mux.HandleFunc("GET /api/snapshot", s.snapshot)
	mux.HandleFunc("GET /api/ws", s.handleWS)
	return mux
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.Header().Set("Cache-Control", "no-store")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(v)
}

// ---- handlers ---------------------------------------------------------

func (s *Server) health(w http.ResponseWriter, r *http.Request) {
	snap := s.Agg.Snapshot()
	status := http.StatusOK
	if !snap.CKPoolOK || !snap.BitcoinOK {
		status = http.StatusServiceUnavailable
	}
	writeJSON(w, status, map[string]any{
		"ok":         snap.CKPoolOK && snap.BitcoinOK,
		"ckpool":     snap.CKPoolOK,
		"bitcoin":    snap.BitcoinOK,
		"last_error": snap.LastError,
	})
}

func (s *Server) snapshot(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.Agg.Snapshot())
}

func (s *Server) pool(w http.ResponseWriter, r *http.Request) {
	snap := s.Agg.Snapshot()
	writeJSON(w, http.StatusOK, map[string]any{
		"pool":                snap.Pool,
		"uptime_seconds":      snap.Uptime,
		"hashrate_hs_1m":      snap.HashrateHs,
		"hashrate_hs_5m":      snap.HashrateHs5m,
		"hashrate_hs_1h":      snap.HashrateHs1h,
		"hashrate_hs_24h":     snap.HashrateHs24h,
		"chain":               snap.Chain,
		"network_hashrate_hs": snap.NetworkHashrateHs,
	})
}

func (s *Server) users(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.Agg.Snapshot().Users)
}

func (s *Server) workers(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.Agg.Snapshot().Workers)
}

func (s *Server) clients(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.Agg.Snapshot().Clients)
}

func (s *Server) blocks(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, s.Agg.Blocks())
}