package logging

import (
	"context"
	"log/slog"
	"os"
	"path/filepath"

	"gemserve/config"

	"github.com/lmittmann/tint"
)

type contextKey string

const CtxLoggerKey contextKey = "logger"

var (
	programLevel *slog.LevelVar = new(slog.LevelVar) // Info by default
	Logger       *slog.Logger
)

func WithLogger(ctx context.Context, logger *slog.Logger) context.Context {
	return context.WithValue(ctx, CtxLoggerKey, logger)
}

func WithAttr(logger *slog.Logger, attrName string, attrValue interface{}) *slog.Logger {
	return logger.With(attrName, attrValue)
}

func FromContext(ctx context.Context) *slog.Logger {
	if logger, ok := ctx.Value(CtxLoggerKey).(*slog.Logger); ok {
		return logger
	}
	// Return default logger instead of panicking
	return slog.Default()
}

func SetupLogging() {
	programLevel.Set(config.CONFIG.LogLevel)
	// With coloring (uses external package)
	opts := &tint.Options{
		AddSource: true,
		Level:     programLevel,
		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
			if a.Key == slog.SourceKey {
				if source, ok := a.Value.Any().(*slog.Source); ok {
					source.File = filepath.Base(source.File)
				}
			}
			// Customize level colors:
			// gray for debug, blue for info,
			// yellow for warnings, black on red bg for errors
			if a.Key == slog.LevelKey && len(groups) == 0 {
				level, ok := a.Value.Any().(slog.Level)
				if ok {
					switch level {
					case slog.LevelDebug:
						// Use grayscale color (232-255 range) for gray/faint debug messages
						return tint.Attr(240, a)
					case slog.LevelInfo:
						// Use color code 12 (bright blue) for info
						return tint.Attr(12, a)
					case slog.LevelWarn:
						// Use color code 11 (bright yellow) for warnings
						return tint.Attr(11, a)
					case slog.LevelError:
						// For black on red background, we need to modify the string value directly
						// since tint.Attr() only supports foreground colors
						return slog.String(a.Key, "\033[30;41m"+a.Value.String()+"\033[0m")
					}
				}
			}
			return a
		},
	}
	Logger = slog.New(tint.NewHandler(os.Stdout, opts))
}