// .Net4
// HttpWebRequestなデータ取得方法
// こっちはうまく動いてる
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;

namespace PixivGetter
{
    public class PixivAPI : IDisposable
    {
        const string API_URI = "http://spapi.pixiv.net/iphone/";
        const double items_per_page = 1.0 / 50;
        private string SSID = null;

        public PixivAPI(string userID, string userPass, int timeout = 10000)
        {
            Debug = false;
            RetakeSSID(userID, userPass);
        }

        public string RetakeSSID(string userID, string userPass)
        {
            try
            {
                if (userID == "") throw new Exception("userIDが空です");
                if (userPass == "") throw new Exception("userPassが空です");
                string post_mes = "mode=login&pixiv_id=" + userID + "&pass=" + userPass + "&skip=0";
                Match m = Regex.Match(getQueryByPost(API_URI + "login.php", post_mes), "PHPSESSID=([0-9a-f]+)");
                if (!m.Success) throw new Exception("SSIDが取得できません");
                SSID = m.Groups[1].Value;
            }
            catch (Exception ex)
            {
                throw new Exception("pixiv login error\r\n" + ex.ToString());
            }
            return SSID;
        }

        public void Dispose()
        {
            if (dbg != null) dbg.Dispose();
        }

        // POSTしてレスポンスのQuery文字列を得る
        private string getQueryByPost(string url, string post_mes)
        {
            byte[] postData = System.Text.Encoding.ASCII.GetBytes(post_mes);
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = postData.Length;
            req.ProtocolVersion = HttpVersion.Version11;
            using (System.IO.Stream st = req.GetRequestStream())
            {
                st.Write(postData, 0, postData.Length);
            }
            return req.GetResponse().ResponseUri.Query;
        }

        // pixiv apiで文字列取得
        private string getData(string api, string query)
        {
            var res = HttpWebRequest.Create(API_URI + api + ".php?dummy=0&" + query + "&PHPSESSID=" + SSID).GetResponse();
            using (Stream st = res.GetResponseStream())
            using (StreamReader sr = new StreamReader(st, Encoding.UTF8))
            {
                return sr.ReadToEnd();
            }
        }

        // 個数から必要ページ数を計算
        public uint PagesOf(int items)
        {
            return (uint)Math.Ceiling(items * items_per_page);
        }

        // pixiv apiでデータ取得
        private List<PixivInfo> getPixivInfoList(string method, string query)
        {
            return PixivInfo.ParseCSV(dbgWrite(getData(method, query)));
        }

        // "お気に入りユーザーの新着"の pageNo ページを取得
        public List<PixivInfo> BookmarkUserNewIllust(uint pageNo = 1)
        {
            return getPixivInfoList("bookmark_user_new_illust", "p=" + pageNo.ToString());
        }

        // "お気に入りユーザーの新着"の pageFrom～pageTo ページを取得
        public List<PixivInfo> BookmarkUserNewIllustFromTo(uint pageFrom, uint pageTo)
        {
            List<PixivInfo> ps = new List<PixivInfo>();
            for (uint i = pageFrom; i <= pageTo; i++)
                ps.AddRange(BookmarkUserNewIllust(i));
            return ps;
        }

        // メンバーのイラスト件数を取得
        public uint MemberIllustCount(uint memberID)
        {
            return uint.Parse(getData("member_illust", "id=" + memberID.ToString() + "&c_mode=count"));
        }
        // メンバーのイラスト情報のpageNoページを取得
        public List<PixivInfo> MemberIllust(uint memberID, uint pageNo = 1)
        {
            return getPixivInfoList("member_illust", "id=" + memberID.ToString() + "&p=" + pageNo.ToString());
        }
        // メンバーのイラスト情報のpageFrom～pageToページを取得
        public List<PixivInfo> MemberIllustFromTo(uint memberID, uint pageFrom, uint pageTo)
        {
            List<PixivInfo> ps = new List<PixivInfo>();
            for (uint i = pageFrom; i <= pageTo; i++)
                ps.AddRange(MemberIllust(memberID, i));
            return ps;
        }
        // メンバーのイラスト情報を全部取得
        public List<PixivInfo> MemberIllustAll(uint memberID)
        {
            return MemberIllustFromTo(memberID, 1, (uint)PagesOf((int)MemberIllustCount(memberID)));
        }

        // イラストIDのイラスト情報を取得
        public List<PixivInfo> Illust(uint illustID)
        {
            return getPixivInfoList("illust", "illust_id=" + illustID.ToString() + "&p=1");
        }

        //----------------------------------------------
        // デバッグ用
        private Debugger dbg = null;
        public bool Debug
        {
            get
            {
                return dbg != null;
            }
            set
            {
                if (value && dbg == null) dbg = new Debugger();
                if (!value && dbg != null) { dbg.Dispose(); dbg = null; }
            }
        }
        private string dbgWrite(string str)
        {
            if (dbg != null) dbg.Write(str);
            return str;
        }
        private string dbgWriteLine(string str)
        {
            if (dbg != null) dbg.WriteLine(str);
            return str;
        }
    }

    // apiが返すデータの格納用
    public class PixivInfo
    {
        public uint IllustID { get; protected set; }
        public uint MemberID { get; protected set; }
        public string Ext { get; protected set; }
        public string Title { get; protected set; }
        public int ImgSrv { get; protected set; }
        public string Author { get; protected set; }
        public string ThumURL { get; protected set; }
        public string MobileImgURL { get; protected set; }
        public string Date { get; protected set; }
        public string[] Tags { get; protected set; }
        public string[] Tools { get; protected set; }
        public uint AppCount { get; protected set; }
        public uint TotalPoint { get; protected set; }
        public uint Views { get; protected set; }
        public string Comment { get; protected set; }
        public uint Manga { get; protected set; }
        public uint BMCount { get; protected set; }
        public string User { get; protected set; }

        enum State { Default, Quoted };

        internal PixivInfo(List<string> pi)
        {
            IllustID = pi[0] == "" ? 0 : uint.Parse(pi[0]);
            MemberID = pi[1] == "" ? 0 : uint.Parse(pi[1]);
            Ext = pi[2];
            Title = pi[3];
            ImgSrv = pi[4] == "" ? 0 : int.Parse(pi[4]);
            Author = pi[5];
            ThumURL = pi[6];
            // 7～8
            MobileImgURL = pi[9];
            // 10～11
            Date = pi[12];
            Tags = Regex.Split(pi[13], " ");
            Tools = Regex.Split(pi[14], " ");
            AppCount = pi[15] == "" ? 0 : uint.Parse(pi[15]);
            TotalPoint = pi[16] == "" ? 0 : uint.Parse(pi[16]);
            Views = pi[17] == "" ? 0 : uint.Parse(pi[17]);
            Comment = pi[18];
            Manga = pi[19] == "" ? 0 : uint.Parse(pi[19]);
            BMCount = pi[22] == "" ? 0 : uint.Parse(pi[22]);
            User = pi[24];
        }

        // 画像のURLリスト
        public List<string> ImgURLs
        {
            get
            {
                List<string> rs = new List<string>();
                string fmt = "http://img{0:D2}.pixiv.net/img/{1}/{2:D}";
                if (Manga > 0)
                {
                    if (IllustID > 11231118) // 1000万(?)を境にオリジナルサイズの _big が追加された模様
                        // 少なくとも11231118には_bigがないことを確認済み
                        fmt += "_big_p{4:D}.{3}";
                    else
                        fmt += "_p{4:D}.{3}";
                    for (int i = 0; i < Manga; i++)
                        rs.Add(String.Format(fmt, ImgSrv, User, IllustID, Ext, i));
                }
                else
                {
                    fmt += ".{3}";
                    rs.Add(String.Format(fmt, ImgSrv, User, IllustID, Ext));
                }
                return rs;
            }
        }

        // apiが返すCSVもどきのデータをパースする
        internal static List<PixivInfo> ParseCSV(string str)
        {
            List<PixivInfo> ps = new List<PixivInfo>();
            List<string> pi = new List<string>();
            string item = "";
            State st = State.Default;
            foreach (var c in str)
            {
                switch (st)
                {
                    case State.Default:
                        switch (c)
                        {
                            case '"':
                                st = State.Quoted;
                                item += c;
                                break;
                            case ',':
                                pi.Add(strip_quote(item));
                                item = "";
                                break;
                            case '\n':
                                pi.Add(strip_quote(item));
                                ps.Add(new PixivInfo(pi));
                                pi = new List<string>();
                                item = "";
                                break;
                            default:
                                item += c;
                                break;
                        }
                        break;
                    case State.Quoted:
                        if (c == '"') st = State.Default;
                        item += c;
                        break;
                    default:
                        throw new Exception("パースエラー");
                }
            }
            if (pi.Count > 0) ps.Add(new PixivInfo(pi));
            return ps;
        }

        // 文字列の最初と最後の"を削除
        internal static string strip_quote(string str)
        {
            if (str.Length == 0) return str;
            int b = str.StartsWith("\"") ? 1 : 0;
            int e = str.Length - (str.EndsWith("\"") ? 2 : 1);
            return str.Substring(b, e);
        }
    }
}