package manifest

import (
	"fmt"
	"mccl/pkg/retriever"
	"mccl/pkg/util"
	"os"
	"path"
	"runtime"
	"strings"
)

type Library struct {
	Downloads struct {
		Artifact    util.File            `json:"artifact"`
		Classifiers map[string]util.File `json:"classifiers"`
	} `json:"downloads"`
	Name  string `json:"name"`
	Url   string `json:"url"`
	Rules []Rule `json:"rules"`
}

func (l *Library) Path() string {
	if l.Downloads.Artifact.Path != "" {
		return l.Downloads.Artifact.Path
	}

	return l.pathFromName()
}

func (l *Library) ToFile() []util.File {
	var f []util.File
	if l.Downloads.Artifact.Url != "" {
		f = append(f, l.Downloads.Artifact)
	} else if l.Url != "" {
		lf := util.File{
			Id:   l.Name,
			Url:  path.Join(l.Url, l.pathFromName()),
			Size: -1,
			Path: l.pathFromName(),
		}
		f = append(f, lf)
	}

	if natives := l.Natives(); natives != nil {
		f = append(f, *natives)
	}

	return f
}

func (l *Library) pathFromName() string {
	parts := strings.Split(l.Name, ":")
	parts = append(strings.Split(parts[0], "."), parts[1:]...)
	pth := path.Join(parts...)
	jarName := strings.Join([]string{parts[len(parts)-2], parts[len(parts)-1]}, "-") + ".jar"
	return path.Join(pth, jarName)
}

func RetrieveLibrary(item retriever.Retrievable, destDir string) (int, error) {
	l := item.(util.File)
	p := path.Join(destDir, l.Path)

	if s, err := os.Stat(p); err == nil && s.Size() == l.Size {
		return int(l.Size), nil
	}

	data, err := item.Retrieve()
	if err != nil {
		return 0, err
	}

	if err := os.MkdirAll(path.Dir(p), 0777); err != nil {
		return 0, err
	}

	tf, err := os.Create(p)
	if err != nil {
		return 0, err
	}
	defer tf.Close()

	written, err := tf.Write(data)
	if err != nil {
		return 0, err
	} else if written != len(data) {
		return 0, fmt.Errorf("written bytes length mismatch. %d != %d", written, len(data))
	}

	return written, nil
}

func (l *Library) CheckRules() bool {
	if strings.Contains(l.Name, "natives") {
		nat := strings.SplitAfter(l.Name, ":")[3]
		nats := strings.Split(nat, "-")

		archR := Rule{Action: ActionAllow}
		if len(nats) == 3 {
			archR.Os.Arch = nats[2]
			l.Rules = append(l.Rules, archR)
		}
	}

	for _, r := range l.Rules {
		if ok, _ := r.Check(); !ok {
			return false
		}
	}

	return true
}

func (l *Library) Natives() *util.File {
	if !l.CheckRules() {
		return nil
	}

	var nativeOs string
	switch v := runtime.GOOS; v {
	case "windows":
		fallthrough
	case "linux":
		nativeOs = "natives-" + v
	case "darwin":
		nativeOs = "natives-macos"
	}

	if len(l.Downloads.Classifiers) > 0 {
		if v, ok := l.Downloads.Classifiers[nativeOs]; ok {
			return &v
		}
	}

	return nil
}