package stdos

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/markbates/pkger/here"
	"github.com/markbates/pkger/internal/maps"
	"github.com/markbates/pkger/pkging"
)

var _ pkging.Pkger = &Pkger{}

type Pkger struct {
	Here  here.Info
	infos *maps.Infos
}

func (f *Pkger) Abs(p string) (string, error) {
	pt, err := f.Parse(p)
	if err != nil {
		return "", err
	}
	return f.AbsPath(pt)
}

func (f *Pkger) AbsPath(pt here.Path) (string, error) {
	if pt.Pkg == f.Here.ImportPath {
		return filepath.Join(f.Here.Dir, pt.Name), nil
	}
	info, err := f.Info(pt.Pkg)
	if err != nil {
		return "", err
	}
	return filepath.Join(info.Dir, pt.Name), nil
}

func New(her here.Info) (*Pkger, error) {
	p := &Pkger{
		infos: &maps.Infos{},
		Here:  her,
	}
	p.infos.Store(her.ImportPath, her)
	return p, nil
}

func (fx *Pkger) Create(name string) (pkging.File, error) {
	name, err := fx.Abs(name)
	if err != nil {
		return nil, err
	}
	f, err := os.Create(name)
	if err != nil {
		return nil, err
	}

	pt, err := fx.Parse(name)
	if err != nil {
		return nil, err
	}

	her, err := fx.Info(pt.Pkg)
	if err != nil {
		return nil, err
	}
	nf := &File{
		File:   f,
		her:    her,
		path:   pt,
		pkging: fx,
	}

	info, err := f.Stat()
	if err != nil {
		return nil, err
	}
	nf.info = pkging.WithName(pt.Name, info)
	return nf, nil
}

func (f *Pkger) Current() (here.Info, error) {
	return f.Here, nil
}

func (f *Pkger) Info(p string) (here.Info, error) {
	info, ok := f.infos.Load(p)
	if ok {
		return info, nil
	}

	info, err := here.Package(p)
	if err != nil {
		return info, err
	}
	f.infos.Store(p, info)
	return info, nil
}

func (f *Pkger) MkdirAll(p string, perm os.FileMode) error {
	p, err := f.Abs(p)
	if err != nil {
		return err
	}
	return os.MkdirAll(p, perm)
}

func (fx *Pkger) Open(name string) (pkging.File, error) {
	pt, err := fx.Parse(name)
	if err != nil {
		return nil, err
	}

	name, err = fx.Abs(name)
	if err != nil {
		return nil, err
	}
	f, err := os.Open(name)
	if err != nil {
		return nil, err
	}

	her, err := fx.Info(pt.Pkg)
	if err != nil {
		return nil, err
	}

	nf := &File{
		File:   f,
		her:    her,
		path:   pt,
		pkging: fx,
	}

	info, err := f.Stat()
	if err != nil {
		return nil, err
	}
	nf.info = pkging.WithName(pt.Name, info)

	return nf, nil
}

func (f *Pkger) Parse(p string) (here.Path, error) {
	return f.Here.Parse(p)
}

func (f *Pkger) Stat(name string) (os.FileInfo, error) {
	pt, err := f.Parse(name)
	if err != nil {
		return nil, err
	}

	abs, err := f.AbsPath(pt)
	if err != nil {
		return nil, err
	}

	info, err := os.Stat(abs)
	if err != nil {
		return nil, err
	}

	info = pkging.WithName(pt.Name, pkging.NewFileInfo(info))

	return info, nil
}

func (f *Pkger) Walk(p string, wf filepath.WalkFunc) error {
	fp, err := f.Abs(p)
	if err != nil {
		return err
	}

	pt, err := f.Parse(p)
	if err != nil {
		return err
	}
	err = filepath.Walk(fp, func(path string, fi os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		pt, err := f.Parse(fmt.Sprintf("%s:%s", pt.Pkg, path))
		if err != nil {
			return err
		}
		info, err := f.Info(pt.Pkg)
		if err != nil {
			return err
		}
		path = strings.TrimPrefix(path, info.Dir)
		pt.Name = path
		return wf(pt.String(), pkging.WithName(path, pkging.NewFileInfo(fi)), nil)
	})

	return err
}

func (fx *Pkger) Remove(name string) error {
	name, err := fx.Abs(name)
	if err != nil {
		return err
	}
	return os.Remove(name)
}

func (fx *Pkger) RemoveAll(name string) error {
	name, err := fx.Abs(name)
	if err != nil {
		return err
	}
	return os.RemoveAll(name)
}