package main

import (
	"fmt"
	"io"
	"net/http"
	"strings"
)

type Forge struct{}

type ForgeVersion struct {
	Version string
	Time    string
	Url     string
}

func parseForgeVersions(html string) []ForgeVersion {
	lines := strings.Split(html, "\n")
	parsing := false
	foundTR := false
	buff := ""
	versions := []ForgeVersion{}
	for _, line := range lines {
		if strings.Contains(line, "<tbody>") {
			parsing = true
		} else if strings.Contains(line, "</tbody>") {
			parsing = false
		} else if parsing {
			if strings.Contains(line, "<tr>") {
				buff = ""
				foundTR = true
			} else if strings.Contains(line, "</tr>") {
				foundTR = false
				versions = append(versions, parseForgeVersion(buff))
			} else if foundTR {
				buff += line + "\n"
			}
		}
	}
	return versions
}

func parseForgeVersion(html string) ForgeVersion {
	lines := strings.Split(html, "\n")
	version := ForgeVersion{}
	for ind, line := range lines {
		if strings.Contains(line, "<td class=\"download-version\">") {
			version.Version = strings.TrimSpace(lines[ind+1])
		} else if strings.Contains(line, "<td class=\"download-time\"") {
			version.Time = strings.Split(strings.Split(line, "<td class=\"download-time\" title=\"")[1], "\">")[0]
		} else if strings.Contains(line, "https://adfoc.us") && strings.Contains(line, "installer.jar") {
			version.Url = strings.Split(strings.Split(line, "&url=")[1], "\">")[0]
		}
	}
	return version
}

func (Forge) GetForgeVersions(mcVersion string) ([]ForgeVersion, error) {
	resp, err := http.Get(fmt.Sprintf("https://files.minecraftforge.net/net/minecraftforge/forge/index_%s.html", mcVersion))
	if err != nil {
		return []ForgeVersion{}, fmt.Errorf("unable to access minecraft forge index: %e", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		return []ForgeVersion{}, fmt.Errorf("unable to access minecraft forge index: %s", err)
	}
	data, _ := io.ReadAll(resp.Body)
	return parseForgeVersions(string(data)), nil
}