#!/bin/bash

shopt -s extglob

fontdir="$1.sfdir"

DEFAULT_GLYPH_WIDTH=555

read -r -p "Font name:" fontname
read -r -p "Full name:" fullname
read -r -p "Unicode page offset (/256, 0 is 0xF3Axx):" offset

mkdir "$fontdir"

cat <<EOF > "$fontdir/font.props"
SplineFontDB: 3.2
FontName: $fontname
FullName: $fullname
Weight: Book
Copyright: Copyright (C) $(date +%Y), $(id -un)
UComments: "$(date +%Y-%M-%d): Created with mkemptyfont.sh"
Version: 001.000
ItalicAngle: 0
UnderlinePosition: -150
UnderlineWidth: 50
Ascent: 800
Descent: 200
sfntRevision: 0x00010000
LayerCount: 2
Layer: 0 0 "Back" 1
Layer: 1 0 "Fore" 0
DisplaySize: -48
AntiAlias: 1
FitToEm: 0
Encoding: Custom
CreationTime: $(date +%s)
ModificationTime: $(date +%s)
DEI: 91125
Lookup: 4 0 1 "'liga' Standard Ligatures in Latin lookup 0" { "'liga' Standard Ligatures in Latin lookup 0-1" } ['liga' ('DFLT' <'dflt' > 'latn' <'dflt' > ) ]
EOF

ord() {
    LC_CTYPE=C printf '%d' "'$1"
}

codepoint="$((0xF3A00 + offset * 256))"
encodingidx=0

# generate the 'raw' replacement glyphs
while read -r glyph_json; do
    while read -r liga_code_point; do
        glyph_file="$fontdir/raw$liga_code_point.glyph"
        if [ ! -e "$glyph_file" ]; then
            echo -n "Generating raw$liga_code_point..."

            cat <<EOF > "$glyph_file"
StartChar: raw$liga_code_point
Encoding: $encodingidx $liga_code_point $encodingidx
Width: $DEFAULT_GLYPH_WIDTH
LayerCount: 2
Comment: "Raw glyph for ligature replacement"
Colour: ff0000
EndChar
EOF
            encodingidx=$((encodingidx + 1))

            echo ' DONE'
        fi
    done < <(jq -r '.ortho | gsub("θ"; "th") | gsub("∫"; "sh") | explode[]' <<<"$glyph_json")
done < <(cue export -p shenikan | jq -c '.dictionary.glyphs[]')

# generate the 'real' ligature glyphs
while read -r glyph_json; do
    liga=( )
    while read -r liga_code_point; do
        liga+=( "raw$liga_code_point" )
    done < <(jq -r '.ortho | gsub("θ"; "th") | gsub("∫"; "sh") | explode[]' <<<"$glyph_json")

    ortho="$(jq -r '.ortho' <<<"$glyph_json")"
    ascii_ortho="$(jq -r '.ortho | gsub("θ"; "th") | gsub("∫"; "sh") | @uri | gsub("%"; "q")' <<<"$glyph_json")"
    echo -n "Generating $ortho..."

    glyph_file="$fontdir/sh$ascii_ortho.glyph"
    cat <<EOF > "$glyph_file"
StartChar: sh$ascii_ortho
Encoding: $encodingidx $codepoint $encodingidx
Width: $DEFAULT_GLYPH_WIDTH
LayerCount: 2
Comment: "Shenikan $ascii_ortho glyph"
Ligature2: "'liga' Standard Ligatures in Latin lookup 0-1" ${liga[*]}
EOF

    if [ "$(jq '.ortho | length' <<<"$glyph_json")" -gt 1 ]; then
        liga=( )
        while read -r liga_code_point; do
            liga+=( "raw$liga_code_point" )
        done < <(jq -r '.ortho | explode | reverse | implode | gsub("θ"; "th") | gsub("∫"; "sh") | explode[]' <<<"$glyph_json")

        echo "Ligature2: \"'liga' Standard Ligatures in Latin lookup 0-1\" ${liga[*]}" >> "$glyph_file"
    fi

    echo 'EndChar' >> "$glyph_file"
    encodingidx=$((encodingidx + 1))
    codepoint=$((codepoint + 1))

    echo ' DONE'
done < <(cue export -p shenikan | jq -c '.dictionary.glyphs[]')