// Package config manages the local mapping between playlist folders and
// Kreativ-Tonies. Credentials are never stored here.
package config

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

	"gopkg.in/yaml.v3"
)

// Mapping maps a local folder (e.g. an exported Deezer playlist) to a Kreativ-Tonie.
type Mapping struct {
	Name        string `yaml:"name"`
	HouseholdID string `yaml:"household_id"`
	TonieID     string `yaml:"tonie_id"`
	TonieName   string `yaml:"tonie_name,omitempty"`
	Folder      string `yaml:"folder"`
	PlaylistRef string `yaml:"playlist_ref,omitempty"`
	Prune       bool   `yaml:"prune"`
}

// Config is the full toni-sync configuration.
type Config struct {
	Mappings []Mapping `yaml:"mappings"`
}

// Get returns the mapping with the given name, if present.
func (c *Config) Get(name string) *Mapping {
	for i := range c.Mappings {
		if c.Mappings[i].Name == name {
			return &c.Mappings[i]
		}
	}
	return nil
}

// Upsert adds a new mapping or replaces an existing one with the same name.
func (c *Config) Upsert(m Mapping) {
	for i := range c.Mappings {
		if c.Mappings[i].Name == m.Name {
			c.Mappings[i] = m
			return
		}
	}
	c.Mappings = append(c.Mappings, m)
}

// Remove deletes the mapping with the given name. Returns false if it was not found.
func (c *Config) Remove(name string) bool {
	for i := range c.Mappings {
		if c.Mappings[i].Name == name {
			c.Mappings = append(c.Mappings[:i], c.Mappings[i+1:]...)
			return true
		}
	}
	return false
}

// DefaultPath returns the default config file location, honoring TONI_SYNC_CONFIG.
func DefaultPath() string {
	if p := os.Getenv("TONI_SYNC_CONFIG"); p != "" {
		return p
	}
	home, err := os.UserHomeDir()
	if err != nil {
		home = "."
	}
	return filepath.Join(home, ".config", "toni-sync", "config.yaml")
}

// Load reads the config from path, or returns an empty Config if it doesn't exist yet.
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return &Config{}, nil
		}
		return nil, fmt.Errorf("reading config %s: %w", path, err)
	}
	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parsing config %s: %w", path, err)
	}
	return &cfg, nil
}

// Save writes the config to path, creating parent directories as needed.
func Save(cfg *Config, path string) error {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return fmt.Errorf("creating config dir: %w", err)
	}
	data, err := yaml.Marshal(cfg)
	if err != nil {
		return fmt.Errorf("encoding config: %w", err)
	}
	if err := os.WriteFile(path, data, 0o644); err != nil {
		return fmt.Errorf("writing config %s: %w", path, err)
	}
	return nil
}