using System;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
using System.Collections;
using System.Globalization;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

/*
 * C# Reddit API Class 1.0
 * By Ruairidh Barnes
 *      reddit: http://reddit.com/user/z3rb
 *      email: ruairidhb@gmail.com
 *      web: http://z3rb.net
 *      
 * 
 * TODO:
 *      Proper error handling for every method
 *      Methods for handling info.json
 *      Methods for handling mine.json
 *      Decent way of handling me.json information
 *      Impliment save/unsave and hide/unhide methods
 *      
 * zlib licence
 * Copyright (c) 2011 Ruairidh Barnes

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software
   in a product, an acknowledgment in the product documentation would be
   appreciated but is not required.

   2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

   3. This notice may not be removed or altered from any source
   distribution.
*/


class RedditAPI
{

    CookieContainer redditCookie;
    WebClient jsonGet;
    //A cache of me.json, since we likely don't need to retrieve it every time we use it
    Hashtable me;
    string usr;
    string cookiefn;
    /// <summary>
    /// Class constructor, logs in or checks for previous login from cookie file
    /// </summary>
    /// <param name="user">Reddit account username</param>
    /// <param name="pswd">Reddit Account password</param>
    /// <param name="cookiefilename">File name of the cookie</param>
    public RedditAPI(string user, string pswd, string cookiefilename = "cookie")
    {
        redditCookie = new CookieContainer();
        jsonGet = new WebClient();
        usr = user;
        cookiefn = cookiefilename;
        redditCookie = Loadcookie(cookiefilename);
        CookieCollection tmpc = redditCookie.GetCookies(new System.Uri("http://www.reddit.com/api/login/" + usr));
        if (redditCookie == null)
        {
            Login(user, pswd);
        }

        GetMe();


    }

    /// <summary>
    /// Logs the user in
    /// </summary>
    /// <param name="user">Reddit account username</param>
    /// <param name="pswd">Reddit account password</param>
    /// <returns>True/False depending on success of login (NYI)</returns>
    private bool Login(string user, string pswd)
    {
        
        HttpWebRequest login = WebRequest.Create("http://www.reddit.com/api/login/" + user) as HttpWebRequest;
        login.CookieContainer = redditCookie;
        login.Method = "POST";
        login.ContentType = "application/x-www-form-urlencoded";

        string postData = string.Format("api_type=json&user={0}&passwd={1}", user, pswd);
        byte[] dataBytes = ASCIIEncoding.ASCII.GetBytes(postData);
        login.ContentLength = dataBytes.Length;
        Stream postStream = login.GetRequestStream();

        postStream.Write(dataBytes, 0, dataBytes.Length);
        postStream.Close();

        
        //Do the actual login
        WebResponse response = login.GetResponse();
        StreamReader r = new StreamReader(response.GetResponseStream());
        Console.WriteLine(r.ReadToEnd());
        Console.WriteLine(redditCookie.GetCookieHeader(new System.Uri("http://www.reddit.com/api/login/" + usr)));

        Savecookie(cookiefn,redditCookie);
        return true;
    }

    /// <summary>
    /// Gets a fresh copy of me.json and saves it to the cache
    /// </summary>
    /// <returns>True/false depending on success (NYI)</returns>
    private Hashtable GetMe()
    {
        jsonGet.Headers["COOKIE"] = redditCookie.GetCookieHeader(new System.Uri("http://www.reddit.com/api/login/" + usr));
        Stream jsonStream = jsonGet.OpenRead("http://www.reddit.com/api/me.json");
        StreamReader jSR = new StreamReader(jsonStream);
        string metmp = jSR.ReadToEnd();
        Hashtable meData = (Hashtable)JSON.JsonDecode(metmp);
        me = (Hashtable)meData["data"];

        return me;
    }

    /// <summary>
    /// Returns me.json's data as a hashtable
    /// </summary>
    /// <returns>me.json's data as a hashtable</returns>
    /// <remarks>e.g. (string)me["modhash"] would be the user's modhash as a string</remarks>
    public Hashtable GetMeCache()
    {
        return me;
    }

    /// <summary>
    /// Checks if the user has mail based on a fresh polling of me.json
    /// </summary>
    /// <returns>True/false depending on if the user has an orangered</returns>
    public bool HasMail()
    {
        //Get a fresh copy of me.json
        GetMe();
        if ((string)me["has_mail"] == "true")
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    /// <summary>
    /// Sends data in POST to the specified URI
    /// </summary>
    /// <param name="data">POST data</param>
    /// <param name="URI">URI to POST data to</param>
    /// <returns>True/false based on success (NYI)</returns>
    private bool SendPOST(string data, string URI)
    {
        HttpWebRequest connect = WebRequest.Create(new System.Uri(URI)) as HttpWebRequest;
        connect.Headers["COOKIE"] = redditCookie.GetCookieHeader(new System.Uri(URI));
        connect.CookieContainer = redditCookie;
        connect.Method = "POST";
        connect.ContentType = "application/x-www-form-urlencoded";

        byte[] dataBytes = ASCIIEncoding.ASCII.GetBytes(data);
        connect.ContentLength = dataBytes.Length;
        Stream postStream = connect.GetRequestStream();

        postStream.Write(dataBytes, 0, dataBytes.Length);
        postStream.Close();

        //Do the actual connection
        connect.GetResponse();
        return true;
    }

    /// <summary>
    /// Posts a comment to the specified "thing"
    /// </summary>
    /// <param name="id">"thing" ID code</param>
    /// <param name="content">Comment contents</param>
    /// <returns>True/false based on success (NYI)</returns>
    /// <remarks>See Glossary here for more info on "things" https://github.com/reddit/reddit/wiki/API </remarks>
    public bool PostComment(string id, string content)
    {
        string modhash = (string)me["modhash"];
        SendPOST(string.Format("thing_id={0}&text={1}&uh={2}", id, content, modhash),
                "http://www.reddit.com/api/comment");
        return true;
    }
    /// <summary>
    /// Casts a vote on the specified "thing"
    /// </summary>
    /// <param name="post">"thing" ID</param>
    /// <param name="type">Vote type, 1, 0 or -1</param>
    /// <returns>True/false based on success (NYI)</returns>
    private bool Vote(string post, int type)
    {
        string modhash = (string)me["modhash"];
        SendPOST(string.Format("id={0}&dir={1}&uh={2}", post, type, modhash),
                "http://www.reddit.com/api/vote");

        return true;
    }

    /// <summary>
    /// Upvotes a "thing"
    /// </summary>
    /// <param name="postID">"thing" ID</param>
    /// <returns></returns>
    /// <remarks>See Glossary here for more info on "things" https://github.com/reddit/reddit/wiki/API </remarks>
    public bool Upvote(string postID)
    {
        Vote(postID, 1);
        return true;
    }

    /// <summary>
    /// Rescinds vote from "thing"
    /// </summary>
    /// <param name="postID">"thing" ID</param>
    /// <returns></returns>
    /// <remarks>See Glossary here for more info on "things" https://github.com/reddit/reddit/wiki/API </remarks>
    public bool UnVote(string postID)
    {
        Vote(postID, 0);
        return true;
    }

    /// <summary>
    /// Downvotes a "thing"
    /// </summary>
    /// <param name="postID">"thing" ID</param>
    /// <returns></returns>
    /// <remarks>See Glossary here for more info on "things" https://github.com/reddit/reddit/wiki/API </remarks>
    public bool Downvote(string postID)
    {
        Vote(postID, -1);
        return true;
    }

    /// <summary>
    /// Posts a link/self post
    /// </summary>
    /// <param name="kind">"self" or "link"</param>
    /// <param name="url">URL or Self Post content</param>
    /// <param name="sr">subreddit</param>
    /// <param name="title">Title of post</param>
    /// <returns></returns>
    private bool Post(string kind, string url, string sr, string title)
    {
        string modhash = (string)me["modhash"];
        SendPOST(string.Format("uh={0}&kind={1}&url={2}&sr={3}&title={4}&r={3}&renderstyle=html", (string)me["modhash"], kind, url, sr, title),
                "http://www.reddit.com/api/submit");
        return true;
    }

    /// <summary>
    /// Posts a self post
    /// </summary>
    /// <param name="link">Text of the self post</param>
    /// <param name="title">Title of submission</param>
    /// <param name="sr">Subreddit to post to</param>
    public void PostSelf(string link, string title, string sr)
    {

        Post("self", link, sr, title);
    }

    /// <summary>
    /// Posts a link
    /// </summary>
    /// <param name="link">URI of post</param>
    /// <param name="title">Title of submission</param>
    /// <param name="sr">Subreddit to post to</param>
    public void PostLink(string link, string title, string sr)
    {
        Post("self", link, sr, title);
    }

    /// <summary>
    /// Saves cookie to file
    /// </summary>
    /// <param name="filename"></param>
    /// <param name="rcookie"></param>
    private void Savecookie(string filename, CookieContainer rcookie)
    {
        Stream stream = File.Open(filename, FileMode.Create);
        BinaryFormatter bFormatter = new BinaryFormatter();
        bFormatter.Serialize(stream, rcookie);
        stream.Close();
    }

    /// <summary>
    /// Loads cookie from file
    /// </summary>
    /// <param name="filename"></param>
    /// <returns></returns>
    private CookieContainer Loadcookie(string filename)
    {
        CookieContainer rcookie;
        Stream stream = File.Open(filename, FileMode.Open);
        BinaryFormatter bFormatter = new BinaryFormatter();
        rcookie = (CookieContainer)bFormatter.Deserialize(stream);
        stream.Close();
        return rcookie;
    }
}


//I didn't want to write my own JSON parser, so I used the free one available here:
// http://techblog.procurios.nl/k/news/view/14605/14863/How-do-I-write-my-own-parser-for-JSON.html
// Included in the same source file because I wanted it to be in 1 cs file

/// <summary>
/// This class encodes and decodes JSON strings.
/// Spec. details, see http://www.json.org/
/// 
/// JSON uses Arrays and Objects. These correspond here to the datatypes ArrayList and Hashtable.
/// All numbers are parsed to doubles.
/// </summary>
public class JSON
{
    public const int TOKEN_NONE = 0;
    public const int TOKEN_CURLY_OPEN = 1;
    public const int TOKEN_CURLY_CLOSE = 2;
    public const int TOKEN_SQUARED_OPEN = 3;
    public const int TOKEN_SQUARED_CLOSE = 4;
    public const int TOKEN_COLON = 5;
    public const int TOKEN_COMMA = 6;
    public const int TOKEN_STRING = 7;
    public const int TOKEN_NUMBER = 8;
    public const int TOKEN_TRUE = 9;
    public const int TOKEN_FALSE = 10;
    public const int TOKEN_NULL = 11;

    private const int BUILDER_CAPACITY = 2000;

    /// <summary>
    /// Parses the string json into a value
    /// </summary>
    /// <param name="json">A JSON string.</param>
    /// <returns>An ArrayList, a Hashtable, a double, a string, null, true, or false</returns>
    public static object JsonDecode(string json)
    {
        bool success = true;

        return JsonDecode(json, ref success);
    }

    /// <summary>
    /// Parses the string json into a value; and fills 'success' with the successfullness of the parse.
    /// </summary>
    /// <param name="json">A JSON string.</param>
    /// <param name="success">Successful parse?</param>
    /// <returns>An ArrayList, a Hashtable, a double, a string, null, true, or false</returns>
    public static object JsonDecode(string json, ref bool success)
    {
        success = true;
        if (json != null)
        {
            char[] charArray = json.ToCharArray();
            int index = 0;
            object value = ParseValue(charArray, ref index, ref success);
            return value;
        }
        else
        {
            return null;
        }
    }

    /// <summary>
    /// Converts a Hashtable / ArrayList object into a JSON string
    /// </summary>
    /// <param name="json">A Hashtable / ArrayList</param>
    /// <returns>A JSON encoded string, or null if object 'json' is not serializable</returns>
    public static string JsonEncode(object json)
    {
        StringBuilder builder = new StringBuilder(BUILDER_CAPACITY);
        bool success = SerializeValue(json, builder);
        return (success ? builder.ToString() : null);
    }

    protected static Hashtable ParseObject(char[] json, ref int index, ref bool success)
    {
        Hashtable table = new Hashtable();
        int token;

        // {
        NextToken(json, ref index);

        bool done = false;
        while (!done)
        {
            token = LookAhead(json, index);
            if (token == JSON.TOKEN_NONE)
            {
                success = false;
                return null;
            }
            else if (token == JSON.TOKEN_COMMA)
            {
                NextToken(json, ref index);
            }
            else if (token == JSON.TOKEN_CURLY_CLOSE)
            {
                NextToken(json, ref index);
                return table;
            }
            else
            {

                // name
                string name = ParseString(json, ref index, ref success);
                if (!success)
                {
                    success = false;
                    return null;
                }

                // :
                token = NextToken(json, ref index);
                if (token != JSON.TOKEN_COLON)
                {
                    success = false;
                    return null;
                }

                // value
                object value = ParseValue(json, ref index, ref success);
                if (!success)
                {
                    success = false;
                    return null;
                }

                table[name] = value;
            }
        }

        return table;
    }

    protected static ArrayList ParseArray(char[] json, ref int index, ref bool success)
    {
        ArrayList array = new ArrayList();

        // [
        NextToken(json, ref index);

        bool done = false;
        while (!done)
        {
            int token = LookAhead(json, index);
            if (token == JSON.TOKEN_NONE)
            {
                success = false;
                return null;
            }
            else if (token == JSON.TOKEN_COMMA)
            {
                NextToken(json, ref index);
            }
            else if (token == JSON.TOKEN_SQUARED_CLOSE)
            {
                NextToken(json, ref index);
                break;
            }
            else
            {
                object value = ParseValue(json, ref index, ref success);
                if (!success)
                {
                    return null;
                }

                array.Add(value);
            }
        }

        return array;
    }

    protected static object ParseValue(char[] json, ref int index, ref bool success)
    {
        switch (LookAhead(json, index))
        {
            case JSON.TOKEN_STRING:
                return ParseString(json, ref index, ref success);
            case JSON.TOKEN_NUMBER:
                return ParseNumber(json, ref index, ref success);
            case JSON.TOKEN_CURLY_OPEN:
                return ParseObject(json, ref index, ref success);
            case JSON.TOKEN_SQUARED_OPEN:
                return ParseArray(json, ref index, ref success);
            case JSON.TOKEN_TRUE:
                NextToken(json, ref index);
                return true;
            case JSON.TOKEN_FALSE:
                NextToken(json, ref index);
                return false;
            case JSON.TOKEN_NULL:
                NextToken(json, ref index);
                return null;
            case JSON.TOKEN_NONE:
                break;
        }

        success = false;
        return null;
    }

    protected static string ParseString(char[] json, ref int index, ref bool success)
    {
        StringBuilder s = new StringBuilder(BUILDER_CAPACITY);
        char c;

        EatWhitespace(json, ref index);

        // "
        c = json[index++];

        bool complete = false;
        while (!complete)
        {

            if (index == json.Length)
            {
                break;
            }

            c = json[index++];
            if (c == '"')
            {
                complete = true;
                break;
            }
            else if (c == '\\')
            {

                if (index == json.Length)
                {
                    break;
                }
                c = json[index++];
                if (c == '"')
                {
                    s.Append('"');
                }
                else if (c == '\\')
                {
                    s.Append('\\');
                }
                else if (c == '/')
                {
                    s.Append('/');
                }
                else if (c == 'b')
                {
                    s.Append('\b');
                }
                else if (c == 'f')
                {
                    s.Append('\f');
                }
                else if (c == 'n')
                {
                    s.Append('\n');
                }
                else if (c == 'r')
                {
                    s.Append('\r');
                }
                else if (c == 't')
                {
                    s.Append('\t');
                }
                else if (c == 'u')
                {
                    int remainingLength = json.Length - index;
                    if (remainingLength >= 4)
                    {
                        // parse the 32 bit hex into an integer codepoint
                        uint codePoint;
                        if (!(success = UInt32.TryParse(new string(json, index, 4), NumberStyles.HexNumber, CultureInfo.InvariantCulture, out codePoint)))
                        {
                            return "";
                        }
                        // convert the integer codepoint to a unicode char and add to string
                        s.Append(Char.ConvertFromUtf32((int)codePoint));
                        // skip 4 chars
                        index += 4;
                    }
                    else
                    {
                        break;
                    }
                }

            }
            else
            {
                s.Append(c);
            }

        }

        if (!complete)
        {
            success = false;
            return null;
        }

        return s.ToString();
    }

    protected static double ParseNumber(char[] json, ref int index, ref bool success)
    {
        EatWhitespace(json, ref index);

        int lastIndex = GetLastIndexOfNumber(json, index);
        int charLength = (lastIndex - index) + 1;

        double number;
        success = Double.TryParse(new string(json, index, charLength), NumberStyles.Any, CultureInfo.InvariantCulture, out number);

        index = lastIndex + 1;
        return number;
    }

    protected static int GetLastIndexOfNumber(char[] json, int index)
    {
        int lastIndex;

        for (lastIndex = index; lastIndex < json.Length; lastIndex++)
        {
            if ("0123456789+-.eE".IndexOf(json[lastIndex]) == -1)
            {
                break;
            }
        }
        return lastIndex - 1;
    }

    protected static void EatWhitespace(char[] json, ref int index)
    {
        for (; index < json.Length; index++)
        {
            if (" \t\n\r".IndexOf(json[index]) == -1)
            {
                break;
            }
        }
    }

    protected static int LookAhead(char[] json, int index)
    {
        int saveIndex = index;
        return NextToken(json, ref saveIndex);
    }

    protected static int NextToken(char[] json, ref int index)
    {
        EatWhitespace(json, ref index);

        if (index == json.Length)
        {
            return JSON.TOKEN_NONE;
        }

        char c = json[index];
        index++;
        switch (c)
        {
            case '{':
                return JSON.TOKEN_CURLY_OPEN;
            case '}':
                return JSON.TOKEN_CURLY_CLOSE;
            case '[':
                return JSON.TOKEN_SQUARED_OPEN;
            case ']':
                return JSON.TOKEN_SQUARED_CLOSE;
            case ',':
                return JSON.TOKEN_COMMA;
            case '"':
                return JSON.TOKEN_STRING;
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
            case '-':
                return JSON.TOKEN_NUMBER;
            case ':':
                return JSON.TOKEN_COLON;
        }
        index--;

        int remainingLength = json.Length - index;

        // false
        if (remainingLength >= 5)
        {
            if (json[index] == 'f' &&
                json[index + 1] == 'a' &&
                json[index + 2] == 'l' &&
                json[index + 3] == 's' &&
                json[index + 4] == 'e')
            {
                index += 5;
                return JSON.TOKEN_FALSE;
            }
        }

        // true
        if (remainingLength >= 4)
        {
            if (json[index] == 't' &&
                json[index + 1] == 'r' &&
                json[index + 2] == 'u' &&
                json[index + 3] == 'e')
            {
                index += 4;
                return JSON.TOKEN_TRUE;
            }
        }

        // null
        if (remainingLength >= 4)
        {
            if (json[index] == 'n' &&
                json[index + 1] == 'u' &&
                json[index + 2] == 'l' &&
                json[index + 3] == 'l')
            {
                index += 4;
                return JSON.TOKEN_NULL;
            }
        }

        return JSON.TOKEN_NONE;
    }

    protected static bool SerializeValue(object value, StringBuilder builder)
    {
        bool success = true;

        if (value is string)
        {
            success = SerializeString((string)value, builder);
        }
        else if (value is Hashtable)
        {
            success = SerializeObject((Hashtable)value, builder);
        }
        else if (value is ArrayList)
        {
            success = SerializeArray((ArrayList)value, builder);
        }
        else if (IsNumeric(value))
        {
            success = SerializeNumber(Convert.ToDouble(value), builder);
        }
        else if ((value is Boolean) && ((Boolean)value == true))
        {
            builder.Append("true");
        }
        else if ((value is Boolean) && ((Boolean)value == false))
        {
            builder.Append("false");
        }
        else if (value == null)
        {
            builder.Append("null");
        }
        else
        {
            success = false;
        }
        return success;
    }

    protected static bool SerializeObject(Hashtable anObject, StringBuilder builder)
    {
        builder.Append("{");

        IDictionaryEnumerator e = anObject.GetEnumerator();
        bool first = true;
        while (e.MoveNext())
        {
            string key = e.Key.ToString();
            object value = e.Value;

            if (!first)
            {
                builder.Append(", ");
            }

            SerializeString(key, builder);
            builder.Append(":");
            if (!SerializeValue(value, builder))
            {
                return false;
            }

            first = false;
        }

        builder.Append("}");
        return true;
    }

    protected static bool SerializeArray(ArrayList anArray, StringBuilder builder)
    {
        builder.Append("[");

        bool first = true;
        for (int i = 0; i < anArray.Count; i++)
        {
            object value = anArray[i];

            if (!first)
            {
                builder.Append(", ");
            }

            if (!SerializeValue(value, builder))
            {
                return false;
            }

            first = false;
        }

        builder.Append("]");
        return true;
    }

    protected static bool SerializeString(string aString, StringBuilder builder)
    {
        builder.Append("\"");

        char[] charArray = aString.ToCharArray();
        for (int i = 0; i < charArray.Length; i++)
        {
            char c = charArray[i];
            if (c == '"')
            {
                builder.Append("\\\"");
            }
            else if (c == '\\')
            {
                builder.Append("\\\\");
            }
            else if (c == '\b')
            {
                builder.Append("\\b");
            }
            else if (c == '\f')
            {
                builder.Append("\\f");
            }
            else if (c == '\n')
            {
                builder.Append("\\n");
            }
            else if (c == '\r')
            {
                builder.Append("\\r");
            }
            else if (c == '\t')
            {
                builder.Append("\\t");
            }
            else
            {
                int codepoint = Convert.ToInt32(c);
                if ((codepoint >= 32) && (codepoint <= 126))
                {
                    builder.Append(c);
                }
                else
                {
                    builder.Append("\\u" + Convert.ToString(codepoint, 16).PadLeft(4, '0'));
                }
            }
        }

        builder.Append("\"");
        return true;
    }

    protected static bool SerializeNumber(double number, StringBuilder builder)
    {
        builder.Append(Convert.ToString(number, CultureInfo.InvariantCulture));
        return true;
    }

    /// <summary>
    /// Determines if a given object is numeric in any way
    /// (can be integer, double, null, etc). 
    /// 
    /// Thanks to mtighe for pointing out Double.TryParse to me.
    /// </summary>
    protected static bool IsNumeric(object o)
    {
        double result;

        return (o == null) ? false : Double.TryParse(o.ToString(), out result);
    }
}