minepkg/minepkg

package instances

import (
    "context"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
)

type fabricLoaderVersion struct {
    Separator string `json:"separator"`
    Build     int    `json:"build"`
    Maven     string `json:"maven"`
    Version   string `json:"version"`
    Stable    bool   `json:"stable"`
}

type fabricMappingVersion struct {
    GameVersion string `json:"gameVersion"`
    Separator   string `json:"separator"`
    Build       int    `json:"build"`
    Maven       string `json:"maven"`
    Version     string `json:"version"`
    Stable      bool   `json:"stable"`
}

func getFabricLoaderVersions(ctx context.Context) ([]fabricLoaderVersion, error) {
    loaders := make([]fabricLoaderVersion, 0)
    res, err := fabricGet(ctx, "https://meta.fabricmc.net/v1/versions/loader")
    if err != nil {
        return nil, err
    }
    buf, err := ioutil.ReadAll(res.Body)
    if err != nil {
        return nil, err
    }

    if err = json.Unmarshal(buf, &loaders); err != nil {
        return nil, err
    }

    return loaders, nil
}

func getFabricMappingVersions(ctx context.Context) ([]fabricMappingVersion, error) {
    loaders := make([]fabricMappingVersion, 0)
    res, err := fabricGet(ctx, "https://meta.fabricmc.net/v1/versions/mappings")
    if err != nil {
        return nil, err
    }
    buf, err := ioutil.ReadAll(res.Body)
    if err != nil {
        return nil, err
    }

    if err = json.Unmarshal(buf, &loaders); err != nil {
        return nil, err
    }

    return loaders, nil
}

func fabricGet(ctx context.Context, url string) (*http.Response, error) {
    req, _ := http.NewRequest("GET", url, nil)
    req.Header.Set("User-Agent", "minepkg (https://github.com/minepkg/minepkg)")
    req.Header.Set("Content-Type", "application/json")
    res, err := http.DefaultClient.Do(req.WithContext(ctx))
    if err == nil && res.StatusCode != 200 {
        return res, fmt.Errorf("fabric meta API did respond with unexpected status %s", res.Status)
    }
    return res, err
}