package main

import (
	"embed"
	"encoding/json"
	"flag"
	"fmt"
	"html/template"
	"net/http"
	"os"
	"sort"
	"strconv"

	"github.com/bdw/deploy/internal/state"
	"github.com/bdw/deploy/internal/templates"
)

//go:embed templates/*.html
var templatesFS embed.FS

func runWebUI(args []string) {
	fs := flag.NewFlagSet("webui", flag.ExitOnError)
	port := fs.String("port", "8080", "Port to run the web UI on")
	help := fs.Bool("h", false, "Show help")

	fs.Parse(args)

	if *help {
		fmt.Fprintf(os.Stderr, `Usage: deploy webui [flags]

Launch a web interface to view and manage deployments.

FLAGS:
  -port string
        Port to run the web UI on (default "8080")
  -h    Show this help message

EXAMPLE:
  # Launch web UI on default port (8080)
  deploy webui

  # Launch on custom port
  deploy webui -port 3000
`)
		os.Exit(0)
	}

	// Parse template
	tmpl, err := template.ParseFS(templatesFS, "templates/webui.html")
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error parsing template: %v\n", err)
		os.Exit(1)
	}

	// Handler for the main page
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		// Reload state on each request to show latest changes
		st, err := state.Load()
		if err != nil {
			http.Error(w, fmt.Sprintf("Error loading state: %v", err), http.StatusInternalServerError)
			return
		}

		// Prepare data for template
		type AppData struct {
			Name   string
			Type   string
			Domain string
			Port   int
			Env    map[string]string
			Host   string
		}

		type HostData struct {
			Host string
			Apps []AppData
		}

		var hosts []HostData
		for hostName, host := range st.Hosts {
			var apps []AppData
			for appName, app := range host.Apps {
				apps = append(apps, AppData{
					Name:   appName,
					Type:   app.Type,
					Domain: app.Domain,
					Port:   app.Port,
					Env:    app.Env,
					Host:   hostName,
				})
			}

			// Sort apps by name
			sort.Slice(apps, func(i, j int) bool {
				return apps[i].Name < apps[j].Name
			})

			hosts = append(hosts, HostData{
				Host: hostName,
				Apps: apps,
			})
		}

		// Sort hosts by name
		sort.Slice(hosts, func(i, j int) bool {
			return hosts[i].Host < hosts[j].Host
		})

		data := struct {
			Hosts []HostData
		}{
			Hosts: hosts,
		}

		if err := tmpl.Execute(w, data); err != nil {
			http.Error(w, fmt.Sprintf("Error rendering template: %v", err), http.StatusInternalServerError)
			return
		}
	})

	// API endpoint to get state as JSON
	http.HandleFunc("/api/state", func(w http.ResponseWriter, r *http.Request) {
		st, err := state.Load()
		if err != nil {
			http.Error(w, fmt.Sprintf("Error loading state: %v", err), http.StatusInternalServerError)
			return
		}

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

	// API endpoint to get rendered configs for an app
	http.HandleFunc("/api/configs", func(w http.ResponseWriter, r *http.Request) {
		host := r.URL.Query().Get("host")
		appName := r.URL.Query().Get("app")

		if host == "" || appName == "" {
			http.Error(w, "Missing host or app parameter", http.StatusBadRequest)
			return
		}

		st, err := state.Load()
		if err != nil {
			http.Error(w, fmt.Sprintf("Error loading state: %v", err), http.StatusInternalServerError)
			return
		}

		app, err := st.GetApp(host, appName)
		if err != nil {
			http.Error(w, fmt.Sprintf("App not found: %v", err), http.StatusNotFound)
			return
		}

		configs := make(map[string]string)

		// Render environment file
		if app.Env != nil && len(app.Env) > 0 {
			envContent := ""
			for k, v := range app.Env {
				envContent += fmt.Sprintf("%s=%s\n", k, v)
			}
			configs["env"] = envContent
			configs["envPath"] = fmt.Sprintf("/etc/deploy/env/%s.env", appName)
		}

		// Render configs based on app type
		if app.Type == "app" {
			// Render systemd service
			workDir := fmt.Sprintf("/var/lib/%s", appName)
			binaryPath := fmt.Sprintf("/usr/local/bin/%s", appName)
			envFilePath := fmt.Sprintf("/etc/deploy/env/%s.env", appName)

			serviceContent, err := templates.SystemdService(map[string]string{
				"Name":       appName,
				"User":       appName,
				"WorkDir":    workDir,
				"BinaryPath": binaryPath,
				"Port":       strconv.Itoa(app.Port),
				"EnvFile":    envFilePath,
				"Args":       app.Args,
			})
			if err != nil {
				http.Error(w, fmt.Sprintf("Error rendering systemd service: %v", err), http.StatusInternalServerError)
				return
			}
			configs["systemd"] = serviceContent
			configs["systemdPath"] = fmt.Sprintf("/etc/systemd/system/%s.service", appName)

			// Render Caddy config
			caddyContent, err := templates.AppCaddy(map[string]string{
				"Domain": app.Domain,
				"Port":   strconv.Itoa(app.Port),
			})
			if err != nil {
				http.Error(w, fmt.Sprintf("Error rendering Caddy config: %v", err), http.StatusInternalServerError)
				return
			}
			configs["caddy"] = caddyContent
			configs["caddyPath"] = fmt.Sprintf("/etc/caddy/sites-enabled/%s.caddy", appName)
		} else if app.Type == "static" {
			// Render Caddy config for static site
			remoteDir := fmt.Sprintf("/var/www/%s", appName)
			caddyContent, err := templates.StaticCaddy(map[string]string{
				"Domain":  app.Domain,
				"RootDir": remoteDir,
			})
			if err != nil {
				http.Error(w, fmt.Sprintf("Error rendering Caddy config: %v", err), http.StatusInternalServerError)
				return
			}
			configs["caddy"] = caddyContent
			configs["caddyPath"] = fmt.Sprintf("/etc/caddy/sites-enabled/%s.caddy", appName)
		}

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

	addr := fmt.Sprintf("localhost:%s", *port)
	fmt.Printf("Starting web UI on http://%s\n", addr)
	fmt.Printf("Press Ctrl+C to stop\n")

	if err := http.ListenAndServe(addr, nil); err != nil {
		fmt.Fprintf(os.Stderr, "Error starting server: %v\n", err)
		os.Exit(1)
	}
}