package app

import (
	"image"
	"log"
	"os"
	"strings"
)

// Parameters to run the pwa-launcher app.
type Parameters struct {
	Title    string
	Icon     string
	iconData image.Image
	URL      string
	Exec     string
}

// Run the main app logic.
func Run(p Parameters) error {
	// If no title or icon given, parse the site.
	if p.Title == "" || p.Icon == "" {
		insights, err := Parse(p.URL)
		if err != nil {
			log.Printf("Insights error: %s", err)
		} else {
			log.Printf("insights: %+v", insights)
			if p.Title == "" && insights.Title != "" {
				p.Title = insights.Title
			}
		}

		if icons, err := DetectIcons(p.URL); err == nil {
			log.Printf("detected icons: %+v", icons)
			insights.Icons = append(insights.Icons, icons...)
		} else {
			log.Printf("DetectIcons error: %s", err)
		}

		log.Printf("Final insights: %+v", insights)

		// Select the best icon.
		if p.Icon == "" {
			icon, err := BestIcon(insights)
			if err != nil {
				panic("No suitable app icon found, provide one manually with -icon")
			}
			p.iconData = icon
		}
	}

	// Do we need to get or download an icon?
	if p.iconData == nil && p.Icon != "" {
		if strings.HasPrefix(p.Icon, "http:") || strings.HasPrefix(p.Icon, "https:") {
			// Download an icon from the web.
			png, err := ParseWebPNG(p.Icon)
			if err != nil {
				log.Fatalf("Couldn't download -icon from %s: %s", p.Icon, err)
			}
			p.iconData = png
		} else {
			fh, err := os.Open(p.Icon)
			if err != nil {
				panic(err)
			}
			png, err := ParsePNG(fh)
			if err != nil {
				panic(err)
			}
			p.iconData = png
			fh.Close()
		}
	}

	// Missing a title?
	if p.Title == "" {
		panic("Couldn't detect a page title, provide one with the -title option")
	}

	// Install the icon and launcher.
	Install(p)
	log.Printf("Launcher installed successfully.")

	return nil
}