package api

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

	"proxmox-router/internal/bwtest"
)

// handleGetBwTestServer returns status and metrics for the local BwTest server
func (s *Server) handleGetBwTestServer(w http.ResponseWriter, r *http.Request) {
	status := s.bwtestMgr.GetServerStatus()
	writeJSON(w, http.StatusOK, status)
}

// handleUpdateBwTestServer updates the server configuration
func (s *Server) handleUpdateBwTestServer(w http.ResponseWriter, r *http.Request) {
	var cfg bwtest.ServerConfig
	if err := json.NewDecoder(r.Body).Decode(&cfg); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "Invalid JSON: " + err.Error()})
		return
	}

	if err := s.bwtestMgr.SetServerConfig(cfg); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}

	writeJSON(w, http.StatusOK, s.bwtestMgr.GetServerStatus())
}

// handleStartBwTest initiates a bandwidth test
func (s *Server) handleStartBwTest(w http.ResponseWriter, r *http.Request) {
	var req bwtest.SessionRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "Invalid JSON: " + err.Error()})
		return
	}

	if req.Target == "" {
		req.Target = "127.0.0.1"
	}
	if req.Port <= 0 {
		req.Port = 2000
	}

	if err := s.bwtestMgr.StartTest(r.Context(), req); err != nil {
		writeJSON(w, http.StatusConflict, map[string]string{"error": err.Error()})
		return
	}

	writeJSON(w, http.StatusOK, s.bwtestMgr.GetTestStatus())
}

// handleStopBwTest terminates any running test
func (s *Server) handleStopBwTest(w http.ResponseWriter, r *http.Request) {
	s.bwtestMgr.StopTest()
	writeJSON(w, http.StatusOK, map[string]bool{"stopped": true})
}

// handleGetBwTestStatus retrieves current status, telemetry, and metrics
func (s *Server) handleGetBwTestStatus(w http.ResponseWriter, r *http.Request) {
	status := s.bwtestMgr.GetTestStatus()
	writeJSON(w, http.StatusOK, status)
}

// handleStreamBwTest streams real-time telemetry samples over Server-Sent Events (SSE)
func (s *Server) handleStreamBwTest(w http.ResponseWriter, r *http.Request) {
	flusher, ok := w.(http.Flusher)
	if !ok {
		http.Error(w, "Streaming unsupported", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")
	w.Header().Set("X-Accel-Buffering", "no")

	subCh, unsubscribe := s.bwtestMgr.SubscribeClient()
	defer unsubscribe()
	ticker := time.NewTicker(500 * time.Millisecond)
	defer ticker.Stop()

	for {
		select {
		case <-r.Context().Done():
			return

		case sample, ok := <-subCh:
			if !ok {
				return
			}
			data, err := json.Marshal(sample)
			if err == nil {
				fmt.Fprintf(w, "data: %s\n\n", data)
				flusher.Flush()
			}

		case <-ticker.C:
			// Send heartbeat/current status snapshot if no sample arrives
			status := s.bwtestMgr.GetTestStatus()
			if !status.Running {
				summaryData, _ := json.Marshal(map[string]interface{}{
					"type":    "status",
					"running": false,
					"summary": status.Summary,
					"error":   status.Error,
				})
				fmt.Fprintf(w, "data: %s\n\n", summaryData)
				flusher.Flush()
				return
			}
		}
	}
}

// handleGetBwTestHistory returns historical test records
func (s *Server) handleGetBwTestHistory(w http.ResponseWriter, r *http.Request) {
	history := s.bwtestMgr.GetHistory()
	writeJSON(w, http.StatusOK, history)
}