package server

import (
	"embed"
	"fmt"
	"html/template"
	"io/fs"
	"log"
	"net"
	"net/http"
	"os"
	"os/exec"
	"path"
	"runtime"
	"strconv"

	"git.nagee.dev/isthisnagee/diary/model"
)

//go:embed templates/*
var files embed.FS

var templates map[string]*template.Template

type App struct{ *model.App }

type DiaryEntryTemplateData struct {
	Entry model.DiaryEntry
	Notes []*model.DiaryEntryNote
}

func LoadTemplates() error {
	if templates == nil {
		templates = make(map[string]*template.Template)
	}
	tmplFiles, err := fs.ReadDir(files, "templates")
	if err != nil {
		return err
	}

	for _, tmpl := range tmplFiles {
		if tmpl.IsDir() {
			continue
		}

		pt, err := template.ParseFS(files, path.Join("templates", tmpl.Name()))
		if err != nil {
			return err
		}

		templates[tmpl.Name()] = pt
	}
	return nil
}

func getFreePort() (int, error) {
	listener, err := net.Listen("tcp", ":0")
	if err != nil {
		return 0, err
	}
	defer listener.Close()
	return listener.Addr().(*net.TCPAddr).Port, nil
}

func openBrowser(url string) {
	var err error

	log.Print(url)

	switch runtime.GOOS {
	case "linux":
		err = exec.Command("xdg-open", url).Start()
	case "windows":
		err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
	case "darwin":
		err = exec.Command("open", url).Start()
	default:
		err = fmt.Errorf("unsupported platform")
	}
	if err != nil {
		log.Fatal(err)
	}

}

func (app *App) ListDiaryEntries(w http.ResponseWriter, r *http.Request) {
	var tmpl, ok = templates["index.html"]
	if !ok {
		http.Error(w, "could not find template index", http.StatusInternalServerError)
		return
	}

	data := app.GetDiaryEntries(model.GetDiaryEntriesQuery{})
	if err := tmpl.Execute(w, data); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func (app *App) DiaryEntry(w http.ResponseWriter, r *http.Request) {
	var tmpl, ok = templates["entry.html"]
	if !ok {
		http.Error(w, "could not find template index", http.StatusInternalServerError)
		return
	}

	var base = path.Base(r.URL.Path)
	var id, err = strconv.Atoi(base)
	if err != nil {
		http.Error(w, "Cannot convert base to int: "+base, http.StatusBadRequest)
	}

	entry, err := app.GetDiaryEntry(int64(id))
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

	var notes = app.GetDiaryEntryNotes(int64(id))

	var templateData = DiaryEntryTemplateData{*entry, notes}

	if err := tmpl.Execute(w, templateData); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func setup() *App {
	home, err := os.UserHomeDir()
	if err != nil {
		panic(err)
	}
	var db_path = path.Join(home, ".diary.sql")
	app, err := model.NewApp(db_path)
	if err != nil {
		panic(err)
	}
	err = LoadTemplates()
	if err != nil {
		panic(err)
	}
	return &App{app}
}

func Run(openBrowserAtUrl bool, defaultPort int) {
	app := setup()

	http.HandleFunc("/", app.ListDiaryEntries)
	http.HandleFunc("/entry/", app.DiaryEntry)

	var port int
	if defaultPort <= 0 {
		freePort, err := getFreePort()
		if err != nil {
			panic(err)
		}
		port = freePort
	} else {
		port = defaultPort
	}

	var url = fmt.Sprintf("http://localhost:%d", port)
	log.Print(url)
	if openBrowserAtUrl {
		log.Print("opening browser")
		openBrowser(url)
	}
	if err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil); err != nil {
		panic(err)
	}

}