package mnt

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

	"github.com/go-errors/errors"
	"gopkg.in/yaml.v3"

	"gensokyo.cafe/xmnt/msg"
	"gensokyo.cafe/xmnt/util"
)

type Preset struct {
	Name       string `yaml:"name"`
	Type       string `yaml:"type"`
	Path       string `yaml:"path"`
	UUID       string `yaml:"uuid"`
	MountPoint string `yaml:"mountpoint"`

	AuthCmd  string `yaml:"auth_cmd"` // e.g. for loading the encryption key
	MountCmd string `yaml:"mount_cmd"`
	CheckCmd string `yaml:"check_cmd"` // check if the mounting was successful

	UnmountCmd      string `yaml:"unmount_cmd"`
	UnAuthCmd       string `yaml:"unauth_cmd"` // e.g. for unloading the encryption key
	UnmountCheckCmd string `yaml:"unmount_check_cmd"`
}

func (p *Preset) String() string {
	return p.Type + ": " + p.Name + " (" + p.Path + ")"
}

func readPreset(path string) (*Preset, error) {
	buf, err := os.ReadFile(path)
	if err != nil {
		return nil, errors.Wrap(err, 0)
	}
	var preset *Preset
	if err = yaml.Unmarshal(buf, &preset); err != nil {
		return nil, errors.Wrap(err, 0)
	}

	if preset.Name == "" {
		preset.Name = filepath.Base(path)[:len(filepath.Base(path))-4] // remove .yml
	}
	return preset, nil
}

func ReadPresets() ([]*Preset, error) {
	cfgDir, err := os.UserConfigDir()
	if err != nil {
		return nil, errors.WrapPrefix(err, "cannot obtain user config dir", 0)
	}

	presetsDir := filepath.Join(cfgDir, "xmnt", "presets")
	dirExist, err := util.DirExists(presetsDir)
	if err != nil {
		return nil, errors.Wrap(err, 0)
	}
	if !dirExist {
		return nil, nil
	}

	var ret []*Preset

	entries, err := os.ReadDir(presetsDir)
	if err != nil {
		return nil, errors.Wrap(err, 0)
	}
	for _, entry := range entries {
		if !entry.Type().IsRegular() || !strings.HasSuffix(entry.Name(), ".yml") {
			continue
		}
		preset, err := readPreset(filepath.Join(presetsDir, entry.Name()))
		if err != nil {
			msg.Errorf("Failed to read preset %s: %v", entry.Name(), err)
			continue
		}
		ret = append(ret, preset)
	}
	return ret, nil
}

func match(s string) ([]*Preset, error) {
	presets, err := ReadPresets()
	if err != nil {
		return nil, errors.Wrap(err, 0)
	}
	for _, p := range presets {
		// for presets, only return exact match.
		if p.Name == s {
			return []*Preset{p}, nil
		}
	}
	return nil, nil
}