package main

import (
	"encoding/json"
	"log"
	"sync"
	"time"

	"github.com/gorilla/websocket"
)

type hub struct {
	mu         sync.Mutex
	clients    map[*websocket.Conn]struct{}
	history    []logMessage
	maxHistory int
}

func newHub() *hub {
	return &hub{
		clients:    make(map[*websocket.Conn]struct{}),
		history:    make([]logMessage, 0, 512),
		maxHistory: 2000,
	}
}

func (h *hub) add(c *websocket.Conn) {
	h.mu.Lock()
	h.clients[c] = struct{}{}
	snapshot := append([]logMessage(nil), h.history...)
	clientCount := len(h.clients)
	h.mu.Unlock()

	log.Printf("ws client connected remote=%s clients=%d", c.RemoteAddr(), clientCount)
	h.replay(c, snapshot)
}

func (h *hub) remove(c *websocket.Conn) {
	h.mu.Lock()
	defer h.mu.Unlock()
	delete(h.clients, c)
	log.Printf("ws client disconnected remote=%s clients=%d", c.RemoteAddr(), len(h.clients))
}

func (h *hub) broadcast(msg logMessage) {
	log.Printf("message process=%s stream=%s line=%q time=%s", msg.Process, msg.Stream, msg.Line, msg.Time)

	payload, err := json.Marshal(msg)
	if err != nil {
		log.Printf("broadcast marshal error process=%s stream=%s err=%v", msg.Process, msg.Stream, err)
		return
	}

	h.mu.Lock()
	defer h.mu.Unlock()

	h.history = append(h.history, msg)
	if len(h.history) > h.maxHistory {
		h.history = h.history[len(h.history)-h.maxHistory:]
	}

	for c := range h.clients {
		_ = c.SetWriteDeadline(time.Now().Add(2 * time.Second))
		if err := c.WriteMessage(websocket.TextMessage, payload); err != nil {
			log.Printf("broadcast write error remote=%s err=%v", c.RemoteAddr(), err)
			_ = c.Close()
			delete(h.clients, c)
		}
	}
}

func (h *hub) replay(c *websocket.Conn, snapshot []logMessage) {
	for _, msg := range snapshot {
		payload, err := json.Marshal(msg)
		if err != nil {
			continue
		}
		_ = c.SetWriteDeadline(time.Now().Add(2 * time.Second))
		if err := c.WriteMessage(websocket.TextMessage, payload); err != nil {
			log.Printf("ws replay failed remote=%s err=%v", c.RemoteAddr(), err)
			return
		}
	}
	log.Printf("ws replay complete remote=%s messages=%d", c.RemoteAddr(), len(snapshot))
}

func (h *hub) status(process, line string) {
	log.Printf("status process=%s line=%s", process, line)
	h.broadcast(logMessage{
		Process: process,
		Stream:  "status",
		Line:    line,
		Time:    time.Now().Format(time.RFC3339),
	})
}