package config

import (
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"strconv"
	"strings"
)

type Config struct {
	Port              int
	DataDir           string
	DBPath            string
	LibraryDir        string
	TempDir           string
	YTDLPPath         string
	FFmpegPath        string
	FFprobePath       string
	BaseURL           string
	Workers           int
	SchedulerInterval int
	LogLevel          string
	LogFormat         string
	Username          string
	PasswordHash      string
}

func New() *Config {
	dataDir := getEnv("VIDARCHIVE_DATA_DIR", "./data")

	return &Config{
		Port:              getEnvInt("VIDARCHIVE_PORT", 8080, 1),
		DataDir:           dataDir,
		DBPath:            getEnv("VIDARCHIVE_DB_PATH", filepath.Join(dataDir, "vidarchive.db")),
		LibraryDir:        getEnv("VIDARCHIVE_LIBRARY_DIR", filepath.Join(dataDir, "library")),
		TempDir:           getEnv("VIDARCHIVE_TEMP_DIR", filepath.Join(dataDir, "temp")),
		YTDLPPath:         getEnv("VIDARCHIVE_YTDLP_PATH", "yt-dlp"),
		FFmpegPath:        getEnv("VIDARCHIVE_FFMPEG_PATH", "ffmpeg"),
		FFprobePath:       getEnv("VIDARCHIVE_FFPROBE_PATH", "ffprobe"),
		BaseURL:           getEnv("VIDARCHIVE_BASE_URL", ""),
		Workers:           getEnvInt("VIDARCHIVE_WORKERS", 2, 1),
		SchedulerInterval: getEnvInt("VIDARCHIVE_SCHEDULER_INTERVAL", 60, 1),
		LogLevel:          getEnv("VIDARCHIVE_LOG_LEVEL", "info"),
		LogFormat:         getEnv("VIDARCHIVE_LOG_FORMAT", "text"),
		Username:          os.Getenv("VIDARCHIVE_USERNAME"),
		PasswordHash:      os.Getenv("VIDARCHIVE_PASSWORD_HASH"),
	}
}

// SetupLogging installs the process-wide slog handler. slog.SetDefault also
// redirects the stdlib log package through it, so output from dependencies is
// formatted and levelled the same way.
func (c *Config) SetupLogging() {
	var level slog.Level
	if err := level.UnmarshalText([]byte(c.LogLevel)); err != nil {
		fmt.Fprintf(os.Stderr, "invalid VIDARCHIVE_LOG_LEVEL %q: %v, using info\n", c.LogLevel, err)
		level = slog.LevelInfo
	}

	opts := &slog.HandlerOptions{Level: level}
	var h slog.Handler = slog.NewTextHandler(os.Stderr, opts)
	if strings.EqualFold(c.LogFormat, "json") {
		h = slog.NewJSONHandler(os.Stderr, opts)
	}
	slog.SetDefault(slog.New(h))
}

func (c *Config) IsHTTPS() bool {
	return strings.HasPrefix(c.BaseURL, "https://")
}

func getEnv(key, defaultVal string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return defaultVal
}

// getEnvInt reads an int with a lower bound. A value below min is rejected in
// favour of the default: a zero or negative worker count, tick interval or port
// would otherwise stall downloads, spin the scheduler or fail to bind.
func getEnvInt(key string, defaultVal, min int) int {
	v := os.Getenv(key)
	if v == "" {
		return defaultVal
	}
	i, err := strconv.Atoi(v)
	if err != nil {
		fmt.Fprintf(os.Stderr, "invalid %s: %v, using default %d\n", key, err, defaultVal)
		return defaultVal
	}
	if i < min {
		fmt.Fprintf(os.Stderr, "invalid %s: %d is below the minimum %d, using default %d\n", key, i, min, defaultVal)
		return defaultVal
	}
	return i
}