##############################################
# Useful CGI functions

NEW_LINE = '
'

fn dprint { echo $* >[1=2] }

fn escape_html { sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g' $* }

fn perm_redirect {
    echo 'Status: 301 Moved Permanantly
Location: '^$1^'

'
    exit
}

fn get_post_args {
    if(~ $#POST_ARGS 0) {
        ifs='&
'       for(pair in `{cat}) {
            pair = `{echo -n $pair | sed 's/=/\&/'} \
            # Maybe we should urldecode on the first pass?
            POST_ARGS = ($POST_ARGS $pair)
            ifs=() \
            if(~ $pair(1) $*)
                $pair(1) = `{echo -n $pair(2) | urldecode | tr -d '
'}
        }
    }
    if not {
        pa = $POST_ARGS
        while(! ~ $#pa 0) {
            ifs=() \
            if(~ $pa(1) $*)
                $pa(1) = `{echo -n $pa(2) | urldecode | tr -d '
'}
            pa = $pa(3-)
        }
    }
}

# Is this really useful?
fn awk_buffer {
    awk '{
        buf = buf $0"\n"
        if(length(buf) > 8192) {
            printf "%s", buf
            buf = ""
        }
    }
    END{ printf "%s", buf }'
}

fn urldecode {
awk '
BEGIN {
    hextab ["0"] = 0; hextab ["8"] = 8;
    hextab ["1"] = 1; hextab ["9"] = 9;
    hextab ["2"] = 2; hextab ["A"] = hextab ["a"] = 10
    hextab ["3"] = 3; hextab ["B"] = hextab ["b"] = 11;
    hextab ["4"] = 4; hextab ["C"] = hextab ["c"] = 12;
    hextab ["5"] = 5; hextab ["D"] = hextab ["d"] = 13;
    hextab ["6"] = 6; hextab ["E"] = hextab ["e"] = 14;
    hextab ["7"] = 7; hextab ["F"] = hextab ["f"] = 15;
}
{
    decoded = ""
    i   = 1
    len = length ($0)
    while ( i <= len ) {
        c = substr ($0, i, 1)
        if ( c == "%" ) {
            if ( i+2 <= len ) {
                c1 = substr ($0, i+1, 1)
                c2 = substr ($0, i+2, 1)
                if ( hextab [c1] == "" || hextab [c2] == "" ) {
                    print "WARNING: invalid hex encoding: %" c1 c2 | "cat >&2"
                } else {
                    code = 0 + hextab [c1] * 16 + hextab [c2] + 0
                    c = sprintf ("%c", code)
                    i = i + 2
                }
            } else {
                print "WARNING: invalid % encoding: " substr ($0, i, len - i)
            }
        } else if ( c == "+" ) {
            c = " "
        }
        decoded = decoded c
        ++i
    }
    printf decoded
}
'
}

fn crop_text {
    max_chars = $0
    awk -v max'='^$max_chars^' ' '
    {
        nc += 1 + length;
        if(nc > max) {
            print substr($0, 1, nc - max) "..."
            exit
        }
        print
    }' 
}


# Cookies
fn set_cookie {
    # TODO: should check input values more carefully
    name = $1
    val = $2
    extraHttpHeaders = ($extraHttpHeaders 'Set-cookie: '^$"name^'='^$"val^'; path=/;')
}
fn get_cookie {
    ifs=';' { co = `{ echo $HTTP_COOKIE } }

    #for(c in $co)
    #    if(~ $c $1^'='*)  # This matching doesn't work
    #        echo $c|sed 's/[^=]*=//' 

    # WARNING: we might be adding a trailing new line
    { for(c in $co) echo $c} | sed -n 's/[^=]*=//p' 
}



##############################################
# More werc-specific functions

fn template { template.awk $* | rc $rcargs }

# .rec parsing
fn parse_rec {
    ifs='
' for(i in `{sed 's/% *//g; /^$/q' < $1}) {
        v = `{echo -n $i | sed 's/^/rec_/; s/=.*//;'} 
        $v = `{echo -n $i | sed 's/^[^=]*=//'}
    }
    ifs=() { rec_data = `{sed -n '/^[^%]./,$p' < $1} }
}


# Auth code

# Cookie format: WERC_USER: name:timestamp:hash(name.timestamp.password)
# login_user can't be used from a template because it sets a cookie 
fn login_user {
    # Note: get_user can use an existing cookie, so we might end up setting an existing cookie
    if(get_user $*)
        set_cookie werc_user $"logged_user^':0:'^$"logged_password
}

# Checks if we are logged in, if called with an argument, we check group membership too
fn check_user {
    if(! get_user)
        status='Not logged in'
    if not if (! ~ $#1 0 && ! grep -s '^'^$logged_user^'$' etc/groups/$1)
        status=User $logged_user not in group $1
    if not
        true
}

# If not logged in, try to get user login info from POST info or from cookie
fn get_user {
    if (~ $#logged_user 0) {
        if (~ $#* 2) {
            user_name = $1 
            user_password $2
        }
        if not if(~ $REQUEST_METHOD POST)
            get_post_args user_name user_password

        if(~ $#user_name 0) { 
            ifs=':' { cu = `{get_cookie werc_user|tr -d $NEW_LINE} }
            if(! ~ $#cu 0) {
                user_name = $cu(1) 
                user_password  = $cu(3)
            }
        }
        auth_user $user_name $user_password
    }
    if not
        true
}

# Check if user_name and user_password represent a valid user account
# If valid, 'log in' by setting logged_user
fn auth_user {
    user_name = $1
    user_password = $2

    pfile = 'etc/users/'^$"user_name^'/password'
    if (~ $#user_name 0 || ~ $#user_password 0)
        status='Auth: missing user name or pass: '^$"user_name^' / '^$"user_password
    if not if(! test -f $pfile)
        status='Auth: cant find '^$pfile
    if not if (! ~ $user_password `{cat $pfile})
        status='Auth: Pass '$user_password' doesnt match '^`{cat $pfile}
    if not {
        logged_user = $user_name
        logged_password = $user_password
        dprint Auth: success
    }
}



# Blog stuff

fn make_blog_post {
    bdir = $1
    btitle = $2
    btext = $3
    if(! ~ 0 $#1 $#2 $#3) {
        date=`{/bin/date +%F}

        n = 1
        for(f in $bdir^$date^'-'*) {
            i = `{echo -n $f | sed -n 's,^.*/'$date'-([0-9]+)_.*,\1,p'|tr -d $NEW_LINE}
            if(! ~ $#i 0 && test $i -ge $n)
                n = `{hoc -e $i'+1'}
        }
        btitle = `{echo -n $"btitle | sed 's/[ 	]+/_/g; 1q'}

        echo $btext > $bdir^'/'^$"date^'-'^$"n^_$"btitle.md 
    }
    if not
        status=Missing blog post arguments $1 $2 $3 
}


# --------
#
#app_blog_methods = ( _post index.rss )
#fn app_blog__post {
#    echo
#}
#
#app_blog___default {
#    if (~ $blog)
#    call_app blogpost
#}
#
## --
#app_blogpost_methods = ( comment  _edit )
#
#fn app_blogpost_comment {
#    call_app comments
#}
#
## --
#app_comments_methods = ( _post _edit )
#
#fn app_comments___default {
#
#}