aitrade/pkg/app/web/server.go

package web

import (
	"context"
	"embed"
	"encoding/json"
	"fmt"
	"html/template"
	"io/fs"
	"log/slog"
	"net/http"
	"sync"
	"time"

	"github.com/pheinrich/aitrade/pkg/app/trader"
	"github.com/pheinrich/aitrade/pkg/config"
	"github.com/pheinrich/aitrade/pkg/db"
	"github.com/pheinrich/aitrade/pkg/model"
)

//go:embed templates/*.html static/*
var embeddedFS embed.FS

type Server struct {
	cfg           *config.WebConfig
	tradingCfg    *config.TradingConfig
	auth          *AuthMiddleware
	tradeRepo     *db.TradeRepository
	balanceRepo   *db.BalanceRepository
	newsRepo      *db.NewsRepository
	whitelistRepo *db.WhitelistRepository
	trader        *trader.Trader
	logger        *slog.Logger
	templates     *template.Template

	// SSE
	sseClients   map[chan string]bool
	sseClientsMu sync.Mutex
}

func NewServer(
	cfg *config.WebConfig,
	tradingCfg *config.TradingConfig,
	oidcCfg *config.OIDCConfig,
	tradeRepo *db.TradeRepository,
	balanceRepo *db.BalanceRepository,
	newsRepo *db.NewsRepository,
	whitelistRepo *db.WhitelistRepository,
	trader *trader.Trader,
	logger *slog.Logger,
) (*Server, error) {
	auth, err := NewAuthMiddleware(oidcCfg, logger)
	if err != nil {
		return nil, fmt.Errorf("failed to create auth middleware: %w", err)
	}

	// Parse templates
	tmpl, err := template.ParseFS(embeddedFS, "templates/*.html")
	if err != nil {
		return nil, fmt.Errorf("failed to parse templates: %w", err)
	}

	return &Server{
		cfg:           cfg,
		tradingCfg:    tradingCfg,
		auth:          auth,
		tradeRepo:     tradeRepo,
		balanceRepo:   balanceRepo,
		newsRepo:      newsRepo,
		whitelistRepo: whitelistRepo,
		trader:        trader,
		logger:        logger,
		templates:     tmpl,
		sseClients:    make(map[chan string]bool),
	}, nil
}

func (s *Server) Run(ctx context.Context) error {
	mux := http.NewServeMux()

	// Static files
	staticFS, err := fs.Sub(embeddedFS, "static")
	if err != nil {
		return fmt.Errorf("failed to get static filesystem: %w", err)
	}
	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(staticFS))))

	// Public endpoints (no auth required)
	mux.HandleFunc("/health", s.handleHealth)
	mux.HandleFunc("/callback", s.auth.HandleCallback)

	// Protected endpoints (auth required)
	mux.Handle("/", s.auth.Middleware(http.HandlerFunc(s.handleOverview)))
	mux.Handle("/overview", s.auth.Middleware(http.HandlerFunc(s.handleOverview)))
	mux.Handle("/trades", s.auth.Middleware(http.HandlerFunc(s.handleTradesPage)))
	mux.Handle("/whitelist", s.auth.Middleware(http.HandlerFunc(s.handleWhitelistPage)))
	mux.Handle("/news", s.auth.Middleware(http.HandlerFunc(s.handleNewsPage)))

	// Content endpoints (partial HTML for SPA)
	mux.Handle("/content/overview", s.auth.Middleware(http.HandlerFunc(s.handleOverviewContent)))
	mux.Handle("/content/trades", s.auth.Middleware(http.HandlerFunc(s.handleTradesContent)))
	mux.Handle("/content/whitelist", s.auth.Middleware(http.HandlerFunc(s.handleWhitelistContent)))
	mux.Handle("/content/news", s.auth.Middleware(http.HandlerFunc(s.handleNewsContent)))

	mux.Handle("/events", s.auth.Middleware(http.HandlerFunc(s.handleSSE)))
	mux.Handle("/api/balance", s.auth.Middleware(http.HandlerFunc(s.handleGetBalance)))
	mux.Handle("/api/config", s.auth.Middleware(http.HandlerFunc(s.handleGetConfig)))
	mux.Handle("/api/news", s.auth.Middleware(http.HandlerFunc(s.handleGetNews)))
	mux.Handle("/api/news/recent", s.auth.Middleware(http.HandlerFunc(s.handleGetNewsRecent)))
	mux.Handle("/api/trades", s.auth.Middleware(http.HandlerFunc(s.handleGetTrades)))
	mux.Handle("/api/trades/", s.auth.Middleware(http.HandlerFunc(s.handleTradeAction)))
	mux.Handle("/api/whitelist", s.auth.Middleware(http.HandlerFunc(s.handleWhitelist)))
	mux.Handle("/api/whitelist/", s.auth.Middleware(http.HandlerFunc(s.handleWhitelistItem)))

	addr := fmt.Sprintf("%s:%s", s.cfg.Host, s.cfg.Port)
	server := &http.Server{
		Addr:    addr,
		Handler: mux,
	}

	s.logger.Info("web server starting", slog.String("addr", addr))

	// Start server in goroutine
	go func() {
		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			s.logger.Error("web server error", slog.Any("error", err))
		}
	}()

	// Wait for context cancellation
	<-ctx.Done()

	s.logger.Info("web server stopping")

	// Shutdown gracefully
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	return server.Shutdown(shutdownCtx)
}

func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{
		"status": "healthy",
	})
}

func (s *Server) handleOverview(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"Title":       "Overview",
		"CurrentPage": "overview",
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "shell.html", data); err != nil {
		s.logger.Error("failed to render template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleTradesPage(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"Title":       "Trades",
		"CurrentPage": "trades",
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "shell.html", data); err != nil {
		s.logger.Error("failed to render template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleWhitelistPage(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"Title":       "Whitelist",
		"CurrentPage": "whitelist",
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "shell.html", data); err != nil {
		s.logger.Error("failed to render template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleNewsPage(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"Title":       "News Feed",
		"CurrentPage": "news",
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "shell.html", data); err != nil {
		s.logger.Error("failed to render template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// Content endpoints (return partial HTML for SPA)
func (s *Server) handleOverviewContent(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "overview-content", nil); err != nil {
		s.logger.Error("failed to render content template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleTradesContent(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "trades-content", nil); err != nil {
		s.logger.Error("failed to render content template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleWhitelistContent(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "whitelist-content", nil); err != nil {
		s.logger.Error("failed to render content template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleNewsContent(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.templates.ExecuteTemplate(w, "news-content", nil); err != nil {
		s.logger.Error("failed to render content template", slog.Any("error", err))
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (s *Server) handleGetTrades(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Get trades from last 7 days
	since := time.Now().AddDate(0, 0, -7)
	trades, err := s.tradeRepo.GetTradesSince(ctx, since)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(trades)
}

func (s *Server) handleGetBalance(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Get live balance from IB Gateway via trader
	balance, err := s.trader.GetLiveBalance(ctx)
	if err != nil {
		s.logger.Warn("failed to get live balance from IB, falling back to DB",
			slog.Any("error", err))

		// Fallback: read from DB if IB Gateway is unavailable
		balance, err = s.balanceRepo.GetLatest(ctx)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		if balance == nil {
			w.Header().Set("Content-Type", "application/json")
			json.NewEncoder(w).Encode(map[string]float64{"TotalValue": 0.0})
			return
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(balance)
}

func (s *Server) handleGetConfig(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"dry_run": s.tradingCfg.DryRun,
	})
}

func (s *Server) handleGetNews(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	news, err := s.newsRepo.GetRecent(ctx, 20)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(news)
}

func (s *Server) handleGetNewsRecent(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Get limit from query parameter, default to 50
	limit := 50
	if limitStr := r.URL.Query().Get("limit"); limitStr != "" {
		fmt.Sscanf(limitStr, "%d", &limit)
	}

	news, err := s.newsRepo.GetRecent(ctx, limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(news)
}

func (s *Server) handleTradeAction(w http.ResponseWriter, r *http.Request) {
	// Parse trade ID from URL: /api/trades/{id}/{action}
	path := r.URL.Path[len("/api/trades/"):]

	var tradeID int64
	var action string
	fmt.Sscanf(path, "%d/%s", &tradeID, &action)

	ctx := r.Context()

	switch action {
	case "approve":
		forceNow := r.URL.Query().Get("force") == "true"
		if err := s.trader.ApproveTrade(ctx, tradeID, forceNow); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		s.BroadcastSSE("trade.approved")

	case "reject":
		var body struct {
			Reason string `json:"reason"`
		}
		json.NewDecoder(r.Body).Decode(&body)

		if err := s.trader.RejectTrade(ctx, tradeID, body.Reason); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		s.BroadcastSSE("trade.rejected")

	default:
		http.Error(w, "Invalid action", http.StatusBadRequest)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func (s *Server) handleWhitelist(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	switch r.Method {
	case http.MethodGet:
		// Get all whitelist entries
		entries, err := s.whitelistRepo.GetAll(ctx)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(entries)

	case http.MethodPost:
		// Create new whitelist entry
		var entry model.WhitelistEntry
		if err := json.NewDecoder(r.Body).Decode(&entry); err != nil {
			http.Error(w, "Invalid request body", http.StatusBadRequest)
			return
		}

		if err := s.whitelistRepo.Create(ctx, &entry); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		s.BroadcastSSE("whitelist.updated")

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(entry)

	default:
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
	}
}

func (s *Server) handleWhitelistItem(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Parse ID from URL: /api/whitelist/{id}
	path := r.URL.Path[len("/api/whitelist/"):]
	var id int64
	fmt.Sscanf(path, "%d", &id)

	switch r.Method {
	case http.MethodGet:
		// Get single whitelist entry
		entry, err := s.whitelistRepo.GetByID(ctx, id)
		if err != nil {
			http.Error(w, err.Error(), http.StatusNotFound)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(entry)

	case http.MethodPut:
		// Update whitelist entry
		var entry model.WhitelistEntry
		if err := json.NewDecoder(r.Body).Decode(&entry); err != nil {
			http.Error(w, "Invalid request body", http.StatusBadRequest)
			return
		}

		entry.ID = id
		if err := s.whitelistRepo.Update(ctx, &entry); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		s.BroadcastSSE("whitelist.updated")

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(entry)

	case http.MethodDelete:
		// Delete whitelist entry
		if err := s.whitelistRepo.Delete(ctx, id); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		s.BroadcastSSE("whitelist.updated")

		w.WriteHeader(http.StatusNoContent)

	default:
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
	}
}

func (s *Server) handleSSE(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")

	// Create client channel
	clientChan := make(chan string)

	s.sseClientsMu.Lock()
	s.sseClients[clientChan] = true
	s.sseClientsMu.Unlock()

	// Remove client on disconnect
	defer func() {
		s.sseClientsMu.Lock()
		delete(s.sseClients, clientChan)
		s.sseClientsMu.Unlock()
		close(clientChan)
	}()

	// Send keep-alive
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-r.Context().Done():
			return
		case msg := <-clientChan:
			fmt.Fprintf(w, "data: %s\n\n", msg)
			w.(http.Flusher).Flush()
		case <-ticker.C:
			fmt.Fprintf(w, ": keepalive\n\n")
			w.(http.Flusher).Flush()
		}
	}
}

func (s *Server) BroadcastSSE(event string) {
	s.sseClientsMu.Lock()
	defer s.sseClientsMu.Unlock()

	for client := range s.sseClients {
		select {
		case client <- event:
		default:
			// Client channel full, skip
		}
	}
}