root/trunk/nntp/nntp.d

/*
This program is distributed without any warranty of any kind!

Author: Benjamin Shropshire (shro8822drop_this at vandals dot uidaho edu)

Please give credit where credit is due. Please don't remove this notice.

*/

import std.conv;
import std.socket;
import std.socketstream;
import std.stream;
import std.date;
import inter;
debug import std.stdio;

const uint NNTP_SOCKET = 119;
//const uint NNTP_SOCKET = 2049;

T max(T)(T[] args)
{
    T ret = T.min;

    foreach(t;args)
        if(t>ret)ret=t;
    
    return ret;
}

bool Prefix(char[] sample, char[] test)
{
    return (sample.length >= test.length) && (sample[0..test.length] == test);
}

class WebNNTP : NNTP
{
    struct Post{char[] subj; char[] date; char[] auth; char[] bod; bool MIME;}

    Post[uint] posts;

    char[] server;
    char[] group;
    uint last;

    void Add(uint i, char[] s, char[] d, char[] a, char[] b)
    {
        debug writef("Trace@"__FILE__":",__LINE__,\n);
        if(i in posts) return;

        Post t;
        with(t)
        {
            subj = s.dup;
            date = d.dup;
            auth = a.dup;
            bod = b.dup;
        }
        if(i > last) last = i;
        posts[i] = t;
    }

    void Add(uint i)
    {
        debug writef("Trace@"__FILE__":",__LINE__,\n);

        CleanOld(100);

        if(i in posts) return;


        auto outgoing = new TcpSocket(AddressFamily.INET);
        outgoing.connect(new InternetAddress(server, NNTP_SOCKET));
        scope(exit) outgoing.close;
        auto outs = new SocketStream(outgoing);
        scope(exit) outs.close;

        char[] res;

        res = outs.readLine;
        debug writef("Trace@"__FILE__":",__LINE__,"(ret=%s)\n", res);
        if((res.length<3) || ('2'!=res[0])) throw new Error("Failed Introduction");

        outs.writeString("group "~group~\r\n);

        res = outs.readLine;
        debug writef("Trace@"__FILE__":",__LINE__,"(ret=%s)\n", res);
        if((res.length<3) || ('2'!=res[0])) throw new Error("No Group");

        Post tmp;
        PullHead(tmp, outs, i);
        PullBody(tmp, outs, i);
        posts[i] = tmp;

    }

        // discard posts more than 100 back
    void CleanOld(int c)
    {
        int[] drop;
        foreach(i;posts.keys)
            if(i<last-c)
                drop~=i;
        foreach(i;drop)
            posts.remove(i);
    }


    private void PullHead(inout Post tmp, Stream outs, int i)
    {
        debug writef("Trace@"__FILE__":",__LINE__,\n);
        if(i>getLast) throw new Error("No message");

        outs.writeString("head "~std.string.toString(i)~\r\n);

        char[] res;
        res = outs.readLine;
        debug writef("Trace@"__FILE__":",__LINE__,"(ret=%s)\n", res);
        if((res.length<3) || ('2'!=res[0])) throw new Error("No Post");

        tmp.MIME = false;

        while(!outs.eof)
        {
            debug writef("Trace@"__FILE__":",__LINE__,\n);
            res = outs.readLine;
            debug writef("Trace@"__FILE__":",__LINE__,\n);

            if(0<res.length && '.' == res[0] && (1==res.length || '.'!=res[1])) break;
                if(Prefix(res, "From:"))    tmp.auth = res["From:".length..$].dup;
            else    if(Prefix(res, "Date:"))    tmp.date = res["Date:".length..$].dup;
            else    if(Prefix(res, "Subject:")) tmp.subj = res["Subject:".length..$].dup;
            else    if(Prefix(res, "Content-Type:"))tmp.MIME = !Prefix(res, "Content-Type: text/plain");
        }
    }

    private void PullBody(inout Post tmp, Stream outs, int i)
    {
        debug writef("Trace@"__FILE__":",__LINE__,\n);
        if(i>last) throw new Error("No message");

        char[][] bd;
        int l;

        outs.writeString("body "~std.string.toString(i)~\r\n);

        char[] res;
        res = outs.readLine;
        debug writef("Trace@"__FILE__":",__LINE__,"(ret=%s)\n", res);
        if((res.length<3) || ('2'!=res[0])) throw new Error("No Post");

        while(true)
        {
            res = outs.readLine;

            if(0<res.length && '.' == res[0]) break;
            res ~= \r;
            bd ~= res;
            l+= res.length;
        }

        tmp.bod.length = l;

        l=0;
        foreach(j,s;bd)
        {
            tmp.bod[l..l+s.length] = s;
            l+=s.length;
        }
    }

    
    this(char[] s, char[] g)
    {
        debug writef("Trace@"__FILE__":",__LINE__,"(%s)\n",s);
        server = s.dup;
        group = g.dup;
    }

    char[] getSubject(uint i){Add(i); return posts[i].subj;}
    char[] getDate(uint i)  {Add(i); return posts[i].date;}
    char[] getAuthor(uint i){Add(i); return posts[i].auth;}
    char[] getBody(uint i)  {Add(i); return posts[i].bod;}

    uint getLast()      
    {

        debug writef("Trace@"__FILE__":",__LINE__,\n);

        auto outgoing = new TcpSocket(AddressFamily.INET);
        outgoing.connect(new InternetAddress(server, NNTP_SOCKET));
        debug writef("Trace@"__FILE__":",__LINE__,": connected\n");
        auto outs = new SocketStream(outgoing);
        scope(exit) outs.close;

        char[] res;
        res = outs.readLine;
        if((0==res.length) || ('2'!=res[0])) throw new Error("Into falure");

        outs.writeString("group "~group~\r\n);

        res = outs.readLine;
        if((7>=res.length) || ('2'!=res[0])) throw new Error("No Group");

        debug writef("Trace@"__FILE__":",__LINE__,\n);


        int at = 4;
        int start;

        while(at<res.length && ' '==res[at]) at++;  // clear " *"
        while(at<res.length && ' '!=res[at]) at++;  // clear "[^ ]*"
        while(at<res.length && ' '==res[at]) at++;  // clear " *"
        while(at<res.length && ' '!=res[at]) at++;  // clear "[^ ]*"
        while(at<res.length && ' '==res[at]) at++;  // clear " *"
        start = at;
        while(at<res.length && ' '!=res[at]) at++;  // find "[^ ]*"

        last = toInt(res[start..at]);

        CleanOld(100);

        return last;
    }

    uint getPrev(uint i)
    {
        debug writef("Trace@"__FILE__":",__LINE__,\n);
        return i>0?i-1:0;
    }
}






void Populate(WebNNTP from)
{
    auto now = getUTCtime();

    for(int i=1; i<1000; i++)
    {
        switch(i%3)
        {
            case 0: from.Add(i,"foo",std.date.toString(now-=10),"you ","Boo\r\nBang\r\nSplat"); break;
            case 1: from.Add(i,"fub",std.date.toString(now-=10),"them","Bwah\r\nha!\r\nha!!!"); break;
            case 2: from.Add(i,"fig",std.date.toString(now-=10),"me  ","blah\r\nblah\r\nblah"); break;
            default: assert(0);
        }
    }

}


class GroupDB : GroupGetter
{
    private ushort[char[]] groups;

    void add(ushort p, char[] n)
    {
        groups[n] = p;
    }

    void remove(char[] n)
    {
        groups.remove(n);
    }

    ushort get(char[] n)
    {
        ushort* ret = n in groups;
        if(null is ret) throw new Error("Unknown NewsGroup");

        return *ret;
    }

}