package config

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

const dir string = "hosts"

type Config struct {
	ManagedConfigurations  []string         `json:"managedConfigurations"`
	BashProfile            BashProfile      `json:"bashProfile"`
	Directories            Directories      `json:"directories"`
	Git                    Git              `json:"git"`
	ExternalConfigurations []ExternalConfig `json:"externalConfigurations"`
}

type Directories struct {
	UseDefaultDirectories bool     `json:"useDefaultDirectories"`
	IncludeXDGDirectories bool     `json:"includeXDGDirectories"`
	AdditionalDirectories []string `json:"additionalDirectories"`
}

type Git struct {
	GpgSign bool    `json:"gpgSign"`
	User    GitUser `json:"user"`
}

type GitUser struct {
	Email      string `json:"email"`
	Name       string `json:"name"`
	SigningKey string `json:"signingKey"`
}

type BashProfile struct {
	Manage               bool                     `json:"manage"`
	Filename             string                   `json:"filename"`
	SessionPaths         []BashProfileSessionPath `json:"sessionPaths"`
	XdgDirectories       map[string]string        `json:"xdgDirectories"`
	EnvironmentVariables map[string]string        `json:"environmentVariables"`
	Aliases              map[string]string        `json:"aliases"`
	Commands             []BashProfileCommand     `json:"commands"`
}

type BashProfileSessionPath struct {
	Path        string `json:"path"`
	Description string `json:"description"`
}

type BashProfileCommand struct {
	Command     string `json:"command"`
	Description string `json:"description"`
}

type ExternalConfig struct {
	Label       string `json:"label"`
	GitRepoURL  string `json:"gitRepoURL"`
	GitRef      string `json:"gitRef"`
	GitRepoPath string `json:"gitRepoPath"`
}

func NewConfig() (Config, error) {
	cfg := defaultConfig()

	path, err := configFilePath()
	if err != nil {
		return Config{}, fmt.Errorf("unable to calculate the config file path: %w", err)
	}

	file, err := os.Open(path)
	if err != nil {
		return Config{}, fmt.Errorf("unable to open the file: %w", err)
	}
	defer file.Close()

	if err = json.NewDecoder(file).Decode(&cfg); err != nil {
		return Config{}, fmt.Errorf("unable to decode the JSON file: %w", err)
	}

	return cfg, nil
}

func configFilePath() (string, error) {
	hostname, err := os.Hostname()
	if err != nil {
		return "", fmt.Errorf("unable to get the machine's hostname: %w", err)
	}

	hostnameParts := strings.SplitN(hostname, "-", 3)

	if len(hostnameParts) != 3 {
		return "", fmt.Errorf("unexpected hostname format")
	}

	identifier := hostnameParts[1]

	return filepath.Join(dir, identifier+".json"), nil
}

func defaultConfig() Config {
	return Config{
		Directories: Directories{
			UseDefaultDirectories: true,
			IncludeXDGDirectories: true,
			AdditionalDirectories: []string{},
		},
		Git: Git{
			GpgSign: false,
			User: GitUser{
				Email:      "",
				Name:       "",
				SigningKey: "",
			},
		},
		ManagedConfigurations:  []string{},
		ExternalConfigurations: []ExternalConfig{},
	}
}