globals.cs

global using System;
global using System.Net;
global using System.Linq;
global using System.Threading.Tasks;
global using System.Collections.Generic;
global using Context = System.Net.HttpListenerContext;

using System.IO;
using System.Text;

namespace Webtech3;

public static class Extensions {
    extension(FileInfo self) {
        public string MimeType {
            get {
                var ext = self.Extension.TrimStart('.').ToLowerInvariant();
                return ext switch {
                    // Text
                    "htm" or "html" => "text/html",
                    "css" => "text/css",
                    "txt" => "text/plain",
                    "csv" => "text/csv",
                    "xml" => "text/xml",
                    "json" => "application/json",
                    "js" => "application/javascript",
                    "rss" => "application/rss+xml",
                    "atom" => "application/atom+xml",                    
                    // Documents
                    "pdf" => "application/pdf",
                    "doc" => "application/msword",
                    "docx" => "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
                    "xls" => "application/vnd.ms-excel",
                    "xlsx" => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                    "ppt" => "application/vnd.ms-powerpoint",
                    "pptx" => "application/vnd.openxmlformats-officedocument.presentationml.presentation",
                    "odt" => "application/vnd.oasis.opendocument.text",
                    "ods" => "application/vnd.oasis.opendocument.spreadsheet",
                    "odp" => "application/vnd.oasis.opendocument.presentation",                    
                    // Images
                    "jpg" or "jpeg" => "image/jpeg",
                    "png" => "image/png",
                    "gif" => "image/gif",
                    "bmp" => "image/bmp",
                    "webp" => "image/webp",
                    "ico" => "image/x-icon",
                    "tiff" or "tif" => "image/tiff",
                    "svg" => "image/svg+xml",
                    "heic" => "image/heic",
                    "heif" => "image/heif",                    
                    // Audio
                    "mp3" => "audio/mpeg",
                    "wav" => "audio/wav",
                    "ogg" or "oga" => "audio/ogg",
                    "flac" => "audio/flac",
                    "aac" => "audio/aac",
                    "m4a" => "audio/mp4",
                    "mid" or "midi" => "audio/midi",
                    "weba" => "audio/webm",                    
                    // Video
                    "mp4" => "video/mp4",
                    "webm" => "video/webm",
                    "avi" => "video/x-msvideo",
                    "mov" => "video/quicktime",
                    "wmv" => "video/x-ms-wmv",
                    "flv" => "video/x-flv",
                    "mkv" => "video/x-matroska",
                    "3gp" => "video/3gpp",
                    "3g2" => "video/3gpp2",
                    "mpeg" or "mpg" => "video/mpeg",                    
                    // Archives
                    "zip" => "application/zip",
                    "rar" => "application/x-rar-compressed",
                    "7z" => "application/x-7z-compressed",
                    "tar" => "application/x-tar",
                    "gz" => "application/gzip",
                    "bz2" => "application/x-bzip2",
                    "xz" => "application/x-xz",                    
                    // Fonts
                    "woff" => "font/woff",
                    "woff2" => "font/woff2",
                    "ttf" => "font/ttf",
                    "otf" => "font/otf",
                    "eot" => "application/vnd.ms-fontobject",                    
                    // Code/Programming
                    "c" => "text/x-c",
                    "cpp" or "cc" or "cxx" => "text/x-c++",
                    "cs" => "text/x-csharp",
                    "java" => "text/x-java-source",
                    "py" => "text/x-python",
                    "php" => "application/x-httpd-php",
                    "sh" => "application/x-sh",
                    "bat" => "application/x-msdos-program",
                    "pl" => "application/x-perl",
                    "rb" => "application/x-ruby",
                    "go" => "text/x-go",
                    "rs" => "text/x-rust",                    
                    // Other
                    "exe" or "dll" => "application/x-msdownload",
                    "iso" => "application/x-iso9660-image",
                    "rtf" => "application/rtf",
                    "epub" => "application/epub+zip",
                    "swf" => "application/x-shockwave-flash",
                    "psd" => "image/vnd.adobe.photoshop",
                    "ai" or "ps" or "eps" => "application/postscript",                
                    // Default fallbacks
                    _ when ext.StartsWith("txt.") => "text/plain",
                    _ when ext.StartsWith("xml.") => "text/xml",
                    _ => "application/octet-stream"
                };
            }
        }
    }
    extension<T>(IEnumerable<T> collection) {
        public int IndexOf(Func<T, bool> predicate) {
            int idx;
            for(idx = 0; !predicate(collection.ElementAt(idx)); idx++);
            return idx;
        }
    }
    extension(string self) {
        internal HTTP.Methods ToHTTPMethod() => self switch {
            "OPTIONS" => HTTP.Methods.OPTIONS,
            "GET" => HTTP.Methods.GET,
            "HEAD" => HTTP.Methods.HEAD,
            "POST" => HTTP.Methods.POST,
            "PUT" => HTTP.Methods.PUT,
            "PATCH" => HTTP.Methods.PATCH,
            "DELETE" => HTTP.Methods.DELETE,
            "TRACE" => HTTP.Methods.TRACE,
            "CONNECT" => HTTP.Methods.CONNECT,
            _ => throw new Exception("Incorrect string")
        };
        /// <summary>
        /// Decode string from base64
        /// </summary>
        /// <returns>Decoded string</returns>
        public string DecodeAsBase64() => Encoding.UTF8.GetString(
            Convert.FromBase64String(self)
        );
    }
}