##############################################
# 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 static_file {
    echo 'Content-Type: '`{select_mime $1}
    echo
    cat $1
    exit
}


# Status is () if at least one arg is found.
fn get_post_args {
    _status='Args not found'
    if(! ~ $REQUEST_METHOD POST)
        _status='No http post!'
    if not 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 )
            _get_post_args_set_var $pair $*
        }
    }
    if not {
        pair=$POST_ARGS
        while(! ~ $#pair 0) {
            _get_post_args_set_var $pair $*
            pair=$pair(3-)
        }
    }
    status=$_status
}
fn _get_post_args_set_var {
    if(~ $1 $*(3-)) {
        ifs=() { $1=`{echo -n $2 | urldecode | tr -d '
'} }
        _status=()
    }
}

# This seems slightly improve performance, but might depend on httpd buffering behavior.
fn awk_buffer {
    awk '{
        buf = buf $0"\n"
        if(length(buf) > 1400) {
            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 {
    ellipsis='...'
    if(~ $#* 2)
        ellipsis=$2

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

    # XXX: we might be adding a trailing new line?
    # The ' ?' is needed to deal with '; ' inter-cookie delimiter
    { for(c in $co) echo $c } | sed -n 's/^ ?'$1'=//p' 
}

fn select_mime {
    m='text/plain'
    if(~ $1 *.css)
        m='text/css'
    if not if(~ $1 *.ico)
        m='image/x-icon'
    if not if(~ $1 *.png)
        m='image/png'
    if not if(~ $1 *.jpg *.jpeg)
        m='image/jpeg'
    if not if(~ $1 *.gif)
        m='image/gif'
    if not if(~ $1 *.pdf)
        m='application/pdf'
    echo $m
}

##############################################
# Generic rc programming helpers

fn ll_add {
    _l=$1^_^$#$1
    $_l=$*(2-)
    $1=( $$1 $_l )
}


##############################################
# Werc-specific functions

fn template { awk -f bin/template.awk $* | rc $rcargs }

# 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: we set the cookie even if it is already there.
    if(get_user $*)
        set_cookie werc_user $"logged_user^':0:'^$"logged_password
}

# Check loggin status, if called with group arg we check membership too
fn check_user {
    if(! get_user)
        status='Not logged in:' $status
    if not if(~ $#1 1 && ! grep -s '^'^$logged_user^'$' etc/groups/$1)
        status=User $logged_user not in group $1
    if not
        status=()
}

# If not logged in, try to get user login info from POST 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
        status=()
}

# 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
        status=()
    }
}

fn user_controls {
    echo User: $"logged_user
}


# .md '(meta-)data' extract
fn get_md_file_attr {
    sed -n '/^\* '$2': /p; /^\* '$2': /q; /^$/q' < $1
}

#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 {
#
#}