package middleware

import (
	"strings"

	"github.com/gin-gonic/gin"
)

// SmartCompression applies gzip compression intelligently
// Skips compression for already compressed formats and small responses
func SmartCompression() gin.HandlerFunc {
	return func(c *gin.Context) {
		// Skip compression for already compressed formats
		contentType := c.GetHeader("Content-Type")
		if shouldSkipCompression(contentType) {
			c.Next()
			return
		}

		// Skip compression for small responses (< 1KB overhead not worth it)
		// This is handled by checking response size in writer

		c.Next()
	}
}

// shouldSkipCompression checks if content type should skip compression
func shouldSkipCompression(contentType string) bool {
	// Already compressed formats
	skipTypes := []string{
		"image/jpeg",
		"image/jpg",
		"image/png",
		"image/gif",
		"image/webp",
		"video/",
		"audio/",
		"application/zip",
		"application/x-zip",
		"application/x-gzip",
		"application/gzip",
		"application/x-compress",
		"application/pdf", // PDFs are already compressed
	}

	for _, skip := range skipTypes {
		if strings.Contains(strings.ToLower(contentType), skip) {
			return true
		}
	}
	return false
}