package profile

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/fs"
	"os"
	"path/filepath"
)

type FileStore struct {
	path string
}

func NewFileStore(path string) *FileStore {
	return &FileStore{path: path}
}

func ConfigPath() (string, error) {
	configDir, err := os.UserConfigDir()
	if err != nil {
		return "", fmt.Errorf("locate user configuration directory: %w", err)
	}
	return filepath.Join(configDir, "proxyctl", "profiles.json"), nil
}

func (s *FileStore) Load() (State, error) {
	data, err := os.ReadFile(s.path)
	if errors.Is(err, fs.ErrNotExist) {
		return State{}, nil
	}
	if err != nil {
		return State{}, fmt.Errorf("read Profile configuration: %w", err)
	}
	var state State
	if err := json.Unmarshal(data, &state); err != nil {
		return State{}, fmt.Errorf("parse Profile configuration: %w", err)
	}
	return state, nil
}

func (s *FileStore) Save(state State) error {
	if err := os.MkdirAll(filepath.Dir(s.path), 0o700); err != nil {
		return fmt.Errorf("create Profile configuration directory: %w", err)
	}
	if err := os.Chmod(filepath.Dir(s.path), 0o700); err != nil {
		return fmt.Errorf("secure Profile configuration directory: %w", err)
	}
	data, err := json.MarshalIndent(state, "", "  ")
	if err != nil {
		return fmt.Errorf("encode Profile configuration: %w", err)
	}
	data = append(data, '\n')
	temp, err := os.CreateTemp(filepath.Dir(s.path), ".profiles-*")
	if err != nil {
		return fmt.Errorf("create temporary Profile configuration: %w", err)
	}
	tempName := temp.Name()
	defer os.Remove(tempName)
	if err := temp.Chmod(0o600); err != nil {
		temp.Close()
		return fmt.Errorf("secure temporary Profile configuration: %w", err)
	}
	if _, err := temp.Write(data); err != nil {
		temp.Close()
		return fmt.Errorf("write temporary Profile configuration: %w", err)
	}
	if err := temp.Sync(); err != nil {
		temp.Close()
		return fmt.Errorf("sync temporary Profile configuration: %w", err)
	}
	if err := temp.Close(); err != nil {
		return fmt.Errorf("close temporary Profile configuration: %w", err)
	}
	if err := os.Rename(tempName, s.path); err != nil {
		return fmt.Errorf("replace Profile configuration: %w", err)
	}
	if err := os.Chmod(s.path, 0o600); err != nil {
		return fmt.Errorf("secure Profile configuration: %w", err)
	}
	dir, err := os.Open(filepath.Dir(s.path))
	if err == nil {
		err = dir.Sync()
		_ = dir.Close()
	}
	if err != nil {
		return fmt.Errorf("sync Profile configuration directory: %w", err)
	}
	return nil
}