package main

import (
	"embed"
	"encoding/json"
	"fmt"
	"io"
	"io/fs"
	"log"
	"net/http"
	"os"
	"os/exec"
	"os/user"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	"github.com/wailsapp/wails/v3/pkg/application"
	"github.com/zalando/go-keyring"
)

//go:embed frontend/dist
var assets embed.FS

//go:embed icon.png
var iconPNG []byte

const (
	keyringService = "com.hubris.oikos-desktop"
	keyringUser    = "oikos"
	version        = "0.1.0"
	updateURL      = "https://git.hubris.network/api/v1/repos/dtoro/oikos/releases"
	pollInterval   = 30 * time.Second
	updateInterval = 6 * time.Hour
)

type OikosConfig struct {
	ApiUrl    string `json:"apiUrl"`
	Token     string `json:"token,omitempty"`
	IsDesktop bool   `json:"isDesktop"`
}

// ---- ConfigService ----

type ConfigService struct{ app *application.App }

func (c *ConfigService) Name() string { return "config" }

func (c *ConfigService) SaveConfig(apiUrl, token string) error {
	cfg := OikosConfig{ApiUrl: apiUrl, Token: token, IsDesktop: true}
	data, _ := json.Marshal(cfg)
	return keyring.Set(keyringService, keyringUser, string(data))
}

func (c *ConfigService) ClearConfig() error {
	return keyring.Delete(keyringService, keyringUser)
}

func (c *ConfigService) EnableAutoStart() error {
	if runtime.GOOS != "darwin" {
		return fmt.Errorf("autostart not supported on %s", runtime.GOOS)
	}
	usr, _ := user.Current()
	dir := filepath.Join(usr.HomeDir, "Library", "LaunchAgents")
	os.MkdirAll(dir, 0755)

	exe, _ := os.Executable()
	plist := fmt.Sprintf(`<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>com.hubris.oikos-desktop</string>
	<key>ProgramArguments</key>
	<array>
		<string>%s</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
	<key>KeepAlive</key>
	<false/>
</dict>
</plist>`, exe)

	return os.WriteFile(filepath.Join(dir, "com.hubris.oikos-desktop.plist"), []byte(plist), 0644)
}

func (c *ConfigService) DisableAutoStart() error {
	if runtime.GOOS != "darwin" {
		return fmt.Errorf("autostart not supported on %s", runtime.GOOS)
	}
	usr, _ := user.Current()
	path := filepath.Join(usr.HomeDir, "Library", "LaunchAgents", "com.hubris.oikos-desktop.plist")
	return os.Remove(path)
}

// ---- Window persistence ----

type windowState struct {
	X      int `json:"x"`
	Y      int `json:"y"`
	Width  int `json:"width"`
	Height int `json:"height"`
}

func windowStatePath() string {
	usr, _ := user.Current()
	return filepath.Join(usr.HomeDir, ".config", "oikos", "window.json")
}

func loadWindowState() *windowState {
	data, err := os.ReadFile(windowStatePath())
	if err != nil {
		return nil
	}
	var ws windowState
	if err := json.Unmarshal(data, &ws); err != nil {
		return nil
	}
	if ws.Width < 200 || ws.Height < 200 {
		return nil
	}
	return &ws
}

func saveWindowState(w application.Window) {
	x, y := w.Position()
	width, height := w.Size()
	ws := windowState{X: x, Y: y, Width: width, Height: height}
	data, _ := json.Marshal(ws)

	usr, _ := user.Current()
	dir := filepath.Join(usr.HomeDir, ".config", "oikos")
	os.MkdirAll(dir, 0755)
	os.WriteFile(filepath.Join(dir, "window.json"), data, 0644)
}

// ---- Config loading ----

func loadConfig() *OikosConfig {
	data, err := keyring.Get(keyringService, keyringUser)
	if err != nil {
		return nil
	}
	var cfg OikosConfig
	if err := json.Unmarshal([]byte(data), &cfg); err != nil {
		return nil
	}
	cfg.IsDesktop = true
	return &cfg
}

// ---- Asset handler ----

func newAssetHandler(cfg *OikosConfig) http.Handler {
	distFS, err := fs.Sub(assets, "frontend/dist")
	if err != nil {
		log.Fatalf("embedded assets: %v", err)
	}

	fallback := http.FileServer(http.FS(distFS))

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		path := r.URL.Path
		if path == "/" || path == "/index.html" {
			data, err := fs.ReadFile(distFS, "index.html")
			if err != nil {
				fallback.ServeHTTP(w, r)
				return
			}
			html := string(data)
			if cfg != nil {
				configJSON, _ := json.Marshal(cfg)
				placeholder := `<script>window.__OIKOS_CONFIG__ = {};</script>`
				injected := fmt.Sprintf(`<script>window.__OIKOS_CONFIG__ = %s;</script>`, configJSON)
				html = strings.ReplaceAll(html, placeholder, injected)
			}
			w.Header().Set("Content-Type", "text/html; charset=utf-8")
			w.Write([]byte(html))
			return
		}
		fallback.ServeHTTP(w, r)
	})
}

// ---- Notifications ----

type dashboardSummary struct {
	ApprovalsPending int `json:"approvals_pending"`
	Signals          struct {
		Critical int `json:"critical"`
	} `json:"signals_by_severity"`
}

func (d *dashboardSummary) alertCount() int {
	return d.ApprovalsPending + d.Signals.Critical
}

func notify(title, subtitle string) {
	if runtime.GOOS != "darwin" {
		return
	}
	script := fmt.Sprintf(
		`display notification "%s" with title "%s" sound name "default"`,
		strings.ReplaceAll(subtitle, `"`, `\"`),
		strings.ReplaceAll(title, `"`, `\"`),
	)
	exec.Command("osascript", "-e", script).Run()
}

func pollDashboard(cfg *OikosConfig) {
	if cfg == nil || cfg.ApiUrl == "" || cfg.Token == "" {
		return
	}

	var lastCount int
	first := true

	for {
		req, err := http.NewRequest("GET", cfg.ApiUrl+"/api/v1/dashboard/summary", nil)
		if err != nil {
			time.Sleep(pollInterval)
			continue
		}
		req.Header.Set("Authorization", "Bearer "+cfg.Token)

		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			time.Sleep(pollInterval)
			continue
		}

		body, _ := io.ReadAll(resp.Body)
		resp.Body.Close()

		var summary dashboardSummary
		if err := json.Unmarshal(body, &summary); err != nil {
			time.Sleep(pollInterval)
			continue
		}

		if first {
			lastCount = summary.alertCount()
			first = false
		} else {
			current := summary.alertCount()
			if current > lastCount {
				notify("Oikos", fmt.Sprintf("%d pending approval(s), %d critical signal(s)", summary.ApprovalsPending, summary.Signals.Critical))
			}
			lastCount = current
		}

		time.Sleep(pollInterval)
	}
}

// ---- Auto-update ----

type giteaRelease struct {
	TagName string `json:"tag_name"`
	Assets  []struct {
		Name               string `json:"name"`
		BrowserDownloadURL string `json:"browser_download_url"`
	} `json:"assets"`
}

func checkUpdates() {
	for {
		resp, err := http.Get(updateURL + "?draft=false&pre-release=false&limit=1")
		if err != nil {
			time.Sleep(updateInterval)
			continue
		}
		body, _ := io.ReadAll(resp.Body)
		resp.Body.Close()

		var releases []giteaRelease
		if err := json.Unmarshal(body, &releases); err != nil || len(releases) == 0 {
			time.Sleep(updateInterval)
			continue
		}

		latest := releases[0]
		latestVersion := strings.TrimPrefix(latest.TagName, "v")
		if latestVersion == version {
			time.Sleep(updateInterval)
			continue
		}

		app := application.Get()
		if app == nil {
			time.Sleep(updateInterval)
			continue
		}

		msg := fmt.Sprintf("Version %s is available (you have %s). Download from Gitea releases.", latestVersion, version)
		app.Dialog.Info().
			SetTitle("Update Available").
			SetMessage(msg).
			Show()
		time.Sleep(updateInterval)
	}
}

// ---- Main ----

func main() {
	cfg := loadConfig()

	app := application.New(application.Options{
		Name:        "Oikos",
		Description: "Homelab Control Room",
		Services: []application.Service{
			application.NewService(&ConfigService{}),
		},
		Assets: application.AssetOptions{
			Handler: newAssetHandler(cfg),
		},
		Mac: application.MacOptions{
			ApplicationShouldTerminateAfterLastWindowClosed: false,
		},
	})

	// --- System tray ---
	systemTray := app.SystemTray.New()
	systemTray.SetLabel("Oikos")
	systemTray.SetTooltip("Oikos")
	systemTray.SetIcon(iconPNG)
	systemTray.SetTemplateIcon(iconPNG)

	trayMenu := application.NewMenu()
	trayMenu.Add("Open Oikos").OnClick(func(ctx *application.Context) {
		for _, w := range app.Window.GetAll() {
			w.Show()
			w.Focus()
		}
	})
	trayMenu.AddSeparator()
	trayMenu.Add("Check for Updates").OnClick(func(ctx *application.Context) {
		go checkUpdates() // force immediate check on demand
	})
	trayMenu.AddSeparator()
	trayMenu.Add("Quit").OnClick(func(ctx *application.Context) {
		app.Quit()
	})
	systemTray.SetMenu(trayMenu)

	// --- Main window ---
	ws := loadWindowState()
	width, height := 1400, 900
	minWidth, minHeight := 1024, 700

	window := app.Window.NewWithOptions(application.WebviewWindowOptions{
		Title:    "Oikos",
		Width:    width,
		Height:   height,
		MinWidth: minWidth,
		MinHeight: minHeight,
		URL:      "/",
	})

	if ws != nil {
		window.SetPosition(ws.X, ws.Y)
		window.SetSize(ws.Width, ws.Height)
	} else {
		window.Center()
	}
	window.Show()

	systemTray.AttachWindow(window)
	systemTray.Run()

	// Register shutdown handler to save window state
	app.OnShutdown(func() {
		saveWindowState(window)
	})

	// Start background goroutines
	go pollDashboard(cfg)
	go checkUpdates()

	err := app.Run()
	if err != nil {
		log.Fatal(err)
	}
}