package services

import (
	"bytes"
	"fmt"
	"mime/multipart"
	"net/http"
	"strconv"

	"github.com/oxplot/papersizes"
)

type Converter interface {
	ToPdf(html string, pageSize string, landscape bool) ([]byte, error)
}

type GotenbergConverter struct {
	BaseUrl string
}

func (g *GotenbergConverter) ToPdf(html string, pageSize string, landscape bool) ([]byte, error) {
	client := &http.Client{}
	defer client.CloseIdleConnections()

	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)

	part, err := writer.CreateFormFile("files", "index.html")
	if err != nil {
		return nil, err
	}

	_, err = part.Write([]byte(html))
	if err != nil {
		return nil, err
	}

	size := papersizes.FromName(pageSize)
	if size == nil {
		return nil, fmt.Errorf("invalid page size: %s", pageSize)
	}

	err = writer.WriteField("paperWidth", strconv.Itoa(size.Width)+"mm")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("paperHeight", strconv.Itoa(size.Height)+"mm")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("landscape", strconv.FormatBool(landscape))
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("marginTop", "0")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("marginBottom", "0")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("marginLeft", "0")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("marginRight", "0")
	if err != nil {
		return nil, err
	}

	err = writer.WriteField("preferCssPageSize", "true")
	if err != nil {
		return nil, err
	}

	err = writer.Close()
	if err != nil {
		return nil, err
	}

	req, err := http.NewRequest("POST", g.BaseUrl+"/forms/chromium/convert/html", body)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Content-Type", writer.FormDataContentType())

	resp, err := client.Do(req)
	if err != nil {
		return nil, err
	}

	defer resp.Body.Close()
	data := new(bytes.Buffer)
	_, err = data.ReadFrom(resp.Body)
	if err != nil {
		return nil, err
	}

	return data.Bytes(), nil
}