package handlers

import (
	"archive/zip"
	"encoding/json"
	"fmt"
	"lash"
	"lash/internal/errx"
	"net/http"
	"os"
	"strconv"
)

type FileHandler struct {
	Ctx      *lash.LashContext
	FileData []FileData
}

type FileData struct {
	Contents []byte
	FileName string
}

type ValidateRequest struct {
	Token string
}

type headers map[string]string

var zipHeaders headers = headers{
	"Content-Disposition": "attachment; filename=lash.zip",
	"Content-Type":        "application/octet-stream",
}

var sent int = 0

func (h FileHandler) APIHandler(w http.ResponseWriter, r *http.Request) {
	if h.hasHitMax() {
		w.WriteHeader(http.StatusTooManyRequests)
		os.Exit(0)
		return
	}
	decoder := json.NewDecoder(r.Body)

	var t ValidateRequest
	err := decoder.Decode(&t)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	if t.Token != lash.Token {
		http.Error(w, "Invalid Token", http.StatusUnauthorized)
		return
	}

	w.WriteHeader(http.StatusOK)
	if len(h.FileData) == 1 {
		headers := headers{
			"Content-Disposition": fmt.Sprintf("attachment; filename=%s", h.FileData[0].FileName),
			"Content-Type":        "application/octet-stream",
			"Content-Length":      strconv.Itoa(len(h.FileData[0].FileName)),
		}
		headers.set(w)

		w.Write(h.FileData[0].Contents)
	} else {
		zipHeaders.set(w)
		h.writeZip(w)
	}
	sent++
}

func (h FileHandler) FileHandler(w http.ResponseWriter, r *http.Request) {
	if h.hasHitMax() {
		w.WriteHeader(http.StatusTooManyRequests)
		os.Exit(0)
		return
	}

	w.WriteHeader(http.StatusOK)
	if len(h.FileData) == 1 {
		headers := headers{
			"Content-Disposition": fmt.Sprintf("attachment; filename=%s", h.FileData[0].FileName),
			"Content-Type":        "application/octet-stream",
			"Content-Length":      strconv.Itoa(len(h.FileData[0].FileName)),
		}
		headers.set(w)

		w.Write(h.FileData[0].Contents)

	} else {
		zipHeaders.set(w)
		h.writeZip(w)
	}
	sent++
}

func (h FileHandler) writeZip(hw http.ResponseWriter) {
	zw := zip.NewWriter(hw)
	defer zw.Close()

	for _, f := range h.FileData {
		w, err := zw.Create(f.FileName)
		if err != nil {
			errx.FatalPerror(err)
		}

		_, err = w.Write(f.Contents)
		if err != nil {
			errx.FatalPerror(err)
		}
	}
}

func (h headers) set(w http.ResponseWriter) {
	for k, v := range h {
		w.Header().Set(k, v)
	}
}

func (h FileHandler) hasHitMax() bool {
	return sent >= h.Ctx.N && h.Ctx.N != -1
}