using System;

using System.Collections.Generic;

using System.Text;

using System.Text.RegularExpressions;

using Growl.CoreLibrary;



namespace Growl.Connector

{

    /// <summary>

    /// Represents a single header in a GNTP message

    /// </summary>

    public class Header

    {

        /// <summary>

        /// The prefix used for application-specific (non-defined) data headers

        /// </summary>

        protected const string DATA_HEADER_PREFIX = "Data-";



        /// <summary>

        /// The prefix used for custom (non-defined) headers

        /// </summary>

        protected const string CUSTOM_HEADER_PREFIX = "X-";



        /// <summary>

        /// The prefix used to identify binary resources that will be passed along with the message

        /// </summary>

        private const string GROWL_RESOURCE_POINTER_PREFIX = "x-growl-resource://";



        /// <summary>

        /// The value of a boolean header that is set to true

        /// </summary>

        private const string BOOL_HEADER_TRUE_VALUE = "Yes";



        /// <summary>

        /// The value of a boolean header that is set to false

        /// </summary>

        private const string BOOL_HEADER_FALSE_VALUE = "No";



        /// <summary>

        /// The RegEx group name for the match that contains the header name (see regExHeader expression below)

        /// </summary>

        private const string HEADER_NAME_REGEX_GROUP_NAME = "HeaderName";



        /// <summary>

        /// The RegEx group name for the match that contains the header value (see regExHeader expression below)

        /// </summary>

        private const string HEADER_VALUE_REGEX_GROUP_NAME = "HeaderValue";



        /// <summary>

        /// The regular expression used to parse the header line

        /// </summary>

        //private static Regex regExHeader = new Regex(@"(?<HeaderName>[^\r\n:]+):\s+(?<HeaderValue>([\s\S]*\r\n)|(.+))");

        private static Regex regExHeader = new Regex(@"(?<HeaderName>[^\r\n:]+):\s+(?<HeaderValue>([\s\S]*\Z)|(.+))");



        /// <summary>

        /// A special <see cref="Header"/> that represents a header that was not found in the message

        /// </summary>

        public static readonly Header NotFoundHeader = new Header();



        /// <summary>

        /// The header name

        /// </summary>

        private string name;



        /// <summary>

        /// The header value

        /// </summary>

        private string val;



        /// <summary>

        /// Indicates if the header is valid or not

        /// </summary>

        private bool isValid;



        /// <summary>

        /// Indicates if the header is a blank line or not

        /// </summary>

        private bool isBlankLine;



        /// <summary>

        /// Indicates if the header is a pointer to a binary resource

        /// </summary>

        private bool isGrowlResourcePointer;



        /// <summary>

        /// The resource pointer value

        /// </summary>

        private string growlResourcePointerID;



        /// <summary>

        /// Indicates if this header is an 'Identifier' header

        /// </summary>

        private bool isIdentifier;



        /// <summary>

        /// Indicates if this header is a custom header

        /// </summary>

        private bool isCustomHeader;



        /// <summary>

        /// Indicates if this header is a application-specific data header

        /// </summary>

        private bool isDataHeader;



        /// <summary>

        /// The binary data associated with this header (if applicable)

        /// </summary>

        private BinaryData growlResource = null;



        /// <summary>

        /// Creates a new uninitialized instance of the <see cref="Header"/> class.

        /// </summary>

        public Header()

        {

            // skip initialize

        }



        /// <summary>

        /// Creates a new instance of the <see cref="Header"/> class

        /// </summary>

        /// <param name="name">The header name</param>

        /// <param name="val">The header value</param>

        public Header(string name, string val)

        {

            Initialize(name, val);

        }



        /// <summary>

        /// Creates a new instance of the <see cref="Header"/> class

        /// </summary>

        /// <param name="name">The header name</param>

        /// <param name="val">The header value</param>

        public Header(string name, bool val)

        {

            string yesOrNo = (val ? BOOL_HEADER_TRUE_VALUE : BOOL_HEADER_FALSE_VALUE);

            Initialize(name, yesOrNo);

        }



        /// <summary>

        /// Creates a new instance of the <see cref="Header"/> class

        /// </summary>

        /// <param name="name">The header name</param>

        /// <param name="val">The header value</param>

        public Header(string name, Resource val)

        {

            if (val != null)

            {

                Initialize(name, val.ToString());

                if (val.IsRawData) this.GrowlResource = val.Data;

            }

        }



        /// <summary>

        /// Initializes the header object

        /// </summary>

        /// <param name="name">The header name</param>

        /// <param name="val">The header value</param>

        private void Initialize(string name, string val)

        {

            this.name = name;

            this.val = val;

            this.isValid = true;

            if (name == null && val == null) this.isBlankLine = true;

            if (!this.isBlankLine)

            {

                if (val != null && val.StartsWith(GROWL_RESOURCE_POINTER_PREFIX, StringComparison.InvariantCultureIgnoreCase))

                {

                    this.isGrowlResourcePointer = true;

                    this.growlResourcePointerID = val.Replace(GROWL_RESOURCE_POINTER_PREFIX, "");

                }



                if (name != null && name == Header.RESOURCE_IDENTIFIER)

                {

                    this.isIdentifier = true;

                }



                if (name != null && name.StartsWith(CUSTOM_HEADER_PREFIX))

                {

                    this.isCustomHeader = true;

                }

                else if (name != null && name.StartsWith(DATA_HEADER_PREFIX))

                {

                    this.isDataHeader = true;

                }

            }

        }



        /// <summary>

        /// Gets the header name

        /// </summary>

        /// <value>

        /// string - Ex: Application-Name: SurfWriter

        /// </value>

        public string Name

        {

            get

            {

                return this.name;

            }

        }



        /// <summary>

        /// Gets the actual header name

        /// </summary>

        /// <value>

        /// string

        /// </value>

        /// <remarks>

        /// If the header is a defined header, this property returns the same value as the Name property.

        /// If the header is a custom header, this property returns the header name with the custom header prefix removed.

        /// If the header is a data header, this property returns the header name with the custom header prefix removed.

        /// </remarks>

        public string ActualName

        {

            get

            {

                if (this.IsCustomHeader)

                    return this.Name.Remove(0, CUSTOM_HEADER_PREFIX.Length);

                else if (this.isDataHeader)

                    return this.name.Remove(0, DATA_HEADER_PREFIX.Length);



                return this.Name;

            }

        }



        /// <summary>

        /// Gets the value of the header

        /// </summary>

        /// <value>

        /// string

        /// </value>

        public string Value

        {

            get

            {

                return this.val;

            }

        }



        /// <summary>

        /// Indicates if the header is valid or not

        /// </summary>

        /// <value>

        /// bool - this value is only <c>true</c> for special cases, like <see cref="Header.NotFoundHeader"/>

        /// </value>

        public bool IsValid

        {

            get

            {

                return this.isValid;

            }

        }



        /// <summary>

        /// Indicates if the header is a blank line of not

        /// </summary>

        /// <value>

        /// <c>true</c> if the header is a blank line,

        /// <c>false</c> otherwise

        /// </value>

        public bool IsBlankLine

        {

            get

            {

                return this.isBlankLine;

            }

        }



        /// <summary>

        /// Indicates if the header is a custom header or not

        /// </summary>

        /// <value>

        /// <c>true</c> if the header is a custom header,

        /// <c>false</c> if the header is a defined header

        /// </value>

        public bool IsCustomHeader

        {

            get

            {

                return this.isCustomHeader;

            }

        }



        /// <summary>

        /// Indicates if the header is an application-specific data header or not

        /// </summary>

        /// <value>

        /// <c>true</c> if the header is a data header,

        /// <c>false</c> if the header is a defined header

        /// </value>

        public bool IsDataHeader

        {

            get

            {

                return this.isDataHeader;

            }

        }



        /// <summary>

        /// Indicates if the header is a <see cref="Header.RESOURCE_IDENTIFIER"/> header

        /// </summary>

        /// <value>

        /// <c>true</c> if the header is a <see cref="Header.RESOURCE_IDENTIFIER"/> header,

        /// <c>false</c> otherwise

        /// </value>

        public bool IsIdentifier

        {

            get

            {

                return this.isIdentifier;

            }

        }



        /// <summary>

        /// Indicates if the header is a binary resource pointer

        /// </summary>

        /// <value>

        /// <c>true</c> if the header is a binary resource pointer,

        /// <c>false</c> otherwise

        /// </value>

        public bool IsGrowlResourcePointer

        {

            get

            {

                return this.isGrowlResourcePointer;

            }

        }



        /// <summary>

        /// Gets the resource pointer value if this is a resource pointer header

        /// </summary>

        /// <value>

        /// string - Ex: x-growl-resource://1234567890

        /// </value>

        public string GrowlResourcePointerID

        {

            get

            {

                return this.growlResourcePointerID;

            }

        }



        /// <summary>

        /// Gets or sets the <see cref="BinaryData"/> associated with this header if this

        /// is a binary resource pointer header.

        /// </summary>

        /// <value>

        /// <see cref="BinaryData"/> or <c>null</c> if this is not a resource pointer header

        /// </value>

        public BinaryData GrowlResource

        {

            get

            {

                return this.growlResource;

            }

            set

            {

                this.growlResource = value;

            }

        }



        /// <summary>

        /// Creates a <see cref="Header"/> from a message line

        /// </summary>

        /// <param name="line">The individual message line</param>

        /// <returns><see cref="Header"/></returns>

        public static Header ParseHeader(string line)

        {

            Header header = null;



            if (line != null)

            {

                line = line.Trim();

                if(String.IsNullOrEmpty(line))

                {

                    header = new Header();

                }

                else

                {

                    // move this to static member variable

                    Match m = regExHeader.Match(line);

                    if (m.Success)

                    {

                        header = new Header(m.Groups[HEADER_NAME_REGEX_GROUP_NAME].Value.Trim(), m.Groups[HEADER_VALUE_REGEX_GROUP_NAME].Value.Trim());

                    }

                }

            }

            return header;

        }



        /// <summary>

        /// Response-Action header

        /// </summary>

        public const string RESPONSE_ACTION = "Response-Action";

        /// <summary>

        /// Application-Name header

        /// </summary>

        public const string APPLICATION_NAME = "Application-Name";

        /// <summary>

        /// Application-Icon header

        /// </summary>

        public const string APPLICATION_ICON = "Application-Icon";

        /// <summary>

        /// Notifications-Count header

        /// </summary>

        public const string NOTIFICATIONS_COUNT = "Notifications-Count";

        /// <summary>

        /// Notification-Name header

        /// </summary>

        public const string NOTIFICATION_NAME = "Notification-Name";

        /// <summary>

        /// Notification-Display-Name header

        /// </summary>

        public const string NOTIFICATION_DISPLAY_NAME = "Notification-Display-Name";

        /// <summary>

        /// Notification-Enabled header

        /// </summary>

        public const string NOTIFICATION_ENABLED = "Notification-Enabled";

        /// <summary>

        /// Notification-Icon header

        /// </summary>

        public const string NOTIFICATION_ICON = "Notification-Icon";

        /// <summary>

        /// Notification-ID header

        /// </summary>

        public const string NOTIFICATION_ID = "Notification-ID";

        /// <summary>

        /// Notification-Title header

        /// </summary>

        public const string NOTIFICATION_TITLE = "Notification-Title";

        /// <summary>

        /// Notification-Text header

        /// </summary>

        public const string NOTIFICATION_TEXT = "Notification-Text";

        /// <summary>

        /// Notification-Sticky header

        /// </summary>

        public const string NOTIFICATION_STICKY = "Notification-Sticky";

        /// <summary>

        /// Notification-Priority header

        /// </summary>

        public const string NOTIFICATION_PRIORITY = "Notification-Priority";

        /// <summary>

        /// Notification-Coalescing-ID header

        /// </summary>

        public const string NOTIFICATION_COALESCING_ID = "Notification-Coalescing-ID";

        /// <summary>

        /// Notification-Callback-Result header

        /// </summary>

        public const string NOTIFICATION_CALLBACK_RESULT = "Notification-Callback-Result";

        /// <summary>

        /// Notification-Callback-Timestamp header

        /// </summary>

        public const string NOTIFICATION_CALLBACK_TIMESTAMP = "Notification-Callback-Timestamp";

        /// <summary>

        /// Notification-Callback-Context header

        /// </summary>

        public const string NOTIFICATION_CALLBACK_CONTEXT = "Notification-Callback-Context";

        /// <summary>

        /// Notification-Callback-Context-Type header

        /// </summary>

        public const string NOTIFICATION_CALLBACK_CONTEXT_TYPE = "Notification-Callback-Context-Type";

        /// <summary>

        /// Notification-Callback-Target header

        /// </summary>

        public const string NOTIFICATION_CALLBACK_TARGET = "Notification-Callback-Target";

        /// <summary>

        /// Notification-Callback-Context-Target header (this is not a valid header, but it is left in for compatibility with existing implementations)

        /// </summary>

        public const string NOTIFICATION_CALLBACK_CONTEXT_TARGET = "Notification-Callback-Context-Target";

        /// <summary>

        /// Identifier header

        /// </summary>

        public const string RESOURCE_IDENTIFIER = "Identifier";

        /// <summary>

        /// Length header

        /// </summary>

        public const string RESOURCE_LENGTH = "Length";

        /// <summary>

        /// Origin-Machine-Name header

        /// </summary>

        public const string ORIGIN_MACHINE_NAME = "Origin-Machine-Name";

        /// <summary>

        /// Origin-Software-Name header

        /// </summary>

        public const string ORIGIN_SOFTWARE_NAME = "Origin-Software-Name";

        /// <summary>

        /// Origin-Software-Version header

        /// </summary>

        public const string ORIGIN_SOFTWARE_VERSION = "Origin-Software-Version";

        /// <summary>

        /// Origin-Platform-Name header

        /// </summary>

        public const string ORIGIN_PLATFORM_NAME = "Origin-Platform-Name";

        /// <summary>

        /// Origin-Platform-Version header

        /// </summary>

        public const string ORIGIN_PLATFORM_VERSION = "Origin-Platform-Version";

        /// <summary>

        /// Error-Code header

        /// </summary>

        public const string ERROR_CODE = "Error-Code";

        /// <summary>

        /// Error-Description header

        /// </summary>

        public const string ERROR_DESCRIPTION = "Error-Description";

        /// <summary>

        /// Received header

        /// </summary>

        public const string RECEIVED = "Received";

        /// <summary>

        /// Subscriber-ID header

        /// </summary>

        public const string SUBSCRIBER_ID = "Subscriber-ID";

        /// <summary>

        /// Subscriber-Name header

        /// </summary>

        public const string SUBSCRIBER_NAME = "Subscriber-Name";

        /// <summary>

        /// Subscriber-Port header

        /// </summary>

        public const string SUBSCRIBER_PORT = "Subscriber-Port";

        /// <summary>

        /// Subscription-TTL header

        /// </summary>

        public const string SUBSCRIPTION_TTL = "Subscription-TTL";

    }

}