package httputils

import (
	"bytes"
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"time"
)

type Handler = func(http.ResponseWriter, *http.Request)

func getPartials() ([]string, map[string]time.Time, error) {
	var modTimes map[string]time.Time = make(map[string]time.Time)
	err := filepath.Walk(partialsFolder, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() && strings.HasSuffix(path, ".html") {
			modTimes[path] = info.ModTime()
		}
		return nil
	})
	paths := make([]string, len(modTimes))
	i := 0
	for path := range modTimes {
		paths[i] = path
		i++
	}
	return paths, modTimes, err
}

const reloadTemplates = true

func GenerateHandler(
	handler func(http.ResponseWriter, *http.Request) bool,
	templateSet TemplateSet,
	template func(http.ResponseWriter, *http.Request) (template string, data any),
	methods []string,
) Handler {
	return func(w http.ResponseWriter, r *http.Request) {
		for _, method := range methods {
			if method == r.Method {
				goto ok
			}
		}
		w.WriteHeader(http.StatusMethodNotAllowed)
		return
	ok:
		renderTemplate := handler(w, r)
		if renderTemplate {
			file_path, data := template(w, r)
			buf := &bytes.Buffer{}
			err := templateSet.ExecuteTemplate(buf, file_path, reflect.ValueOf(data))
			if err != nil {
				fmt.Println(err)
				w.WriteHeader(http.StatusInternalServerError)
				fmt.Fprint(w, "500 Internal Server Error")
				return
			}
			w.Header().Set("Content-Type", "text/html; charset=utf-8")
			fmt.Fprint(w, buf.String())
		}
	}
}

func GenerateSseHandler(handler Handler) Handler {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			w.WriteHeader(http.StatusMethodNotAllowed)
			return
		}
		w.Header().Set("Content-Type", "text/event-stream")
		w.Header().Set("Cache-Control", "no-cache")
		w.Header().Set("Connection", "keep-alive")
		w.WriteHeader(http.StatusOK)
		handler(w, r)
	}
}