#!/bin/bash

# Outputs a build.ninja script for placing into $1 (or output/ if omitted)

scriptdir="$(dirname -- "${BASH_SOURCE[0]}")"
builddir="${1-output}"

cue_sources=( "$scriptdir"/*.cue "$scriptdir"/*.yaml )
everything="$(cue export -- "${cue_sources[@]}" | jq -c)"
ASSET_TO_JSON="| to_entries[] | .value + { name: .key }"
mapfile -t assets < <(jq -c ".assets $ASSET_TO_JSON" <<<"$everything")
mapfile -t pseudos < <(jq -c ".pseudoassets $ASSET_TO_JSON" <<<"$everything")

# base is the directory that contains the script
base="$(realpath -s --relative-to="$builddir" "$scriptdir")"

# root is the directory that the assets are generated into
root=.

relative_cue_sources=( )
for cue_source in "${cue_sources[@]}"; do
    relative_cue_sources+=( "$base/$cue_source" )
done

cat <<EOF
# Generated from configure.sh, do not edit this file!

base = $base

EOF

cat "$scriptdir/rules.ninja"

cat <<EOF

rule configure
  description = recreate build.ninja using $base/configure.sh
  command = $base/configure.sh $root
  generator = 1
  restat = 1

build ./build.ninja: configure | $base/configure.sh ${relative_cue_sources[*]}

build $root/.everything.json: cuegen ${relative_cue_sources[*]}
  filter = .

EOF

for asset in "${assets[@]}" "${pseudos[@]}"; do
    # reset asset variables, also quiets shellcheck
    name=
    print=
    kind=
    source=
    template=
    size=
    data=
    contents=

    eval "$(jq -r 'to_entries[] | "\(.key)=\(.value|@text|@sh)"' <<<"$asset")"
    rawsuffix="$(echo -n "$print" | sed 's/.*/raw./')"

    case $kind in
        template)
            cat <<EOF
build $root/.$name.updated | $root/.$name.json: extract $root/.everything.json
  filter = --arg asset '$name' '.assets[\$\$asset].data'
  target = $root/.$name.json

build $root/tex/$name.tex: template2tex $root/.$name.json | $base/templates/$template
  template = $base/templates/$template

build $root/$name.pdf: tex2pdf $root/tex/$name.tex || $root/.$name.pdf.dd
  dyndep = $root/.$name.pdf.dd

build $root/.$name.pdf.dd: scantex $root/tex/$name.tex
  target = $root/$name.pdf

build $root/$name.${rawsuffix}png: pdf2png $root/$name.pdf
  w = ${size%x*}
  h = ${size#*x}

EOF
        ;;

        image)
            cat <<EOF
build $root/$name.${rawsuffix}png: copy $base/$source

EOF
        ;;

        tex)
            cat <<EOF
build $root/$name.pdf: tex2pdf $base/$source || $root/.$name.pdf.dd
  dyndep = $root/.$name.pdf.dd

build $root/.$name.pdf.dd: scantex $base/$source
  target = $root/$name.pdf

build $root/$name.${rawsuffix}png: pdf2png $root/$name.pdf
  w = ${size%x*}
  h = ${size#*x}

EOF
        ;;

        texdoc)
            cat <<EOF
build $root/$name.pdf: tex2pdf2x $base/$source || $root/.$name.pdf.dd
  dyndep = $root/.$name.pdf.dd

build $root/.$name.pdf.dd: scantex $base/$source
  target = $root/$name.pdf

EOF
        ;;

        cat)
            mapfile -t ins < <(jq -r ".[]" <<<"$contents")
            echo -n "build $root/$name.pdf: pdfunite"
            for i in "${ins[@]}"; do
                echo -n " $root/$i.pdf"
            done
            echo
            ;;

        *)
            echo "ERROR! UNKNOWN ASSET TYPE $kind!" >&2
            ;;
    esac

    # always run convert if print is non-empty
    if [ -n "$print" ]; then
        cat <<EOF
build $root/$name.png: convert $root/$name.raw.png
  args = $print

EOF
    fi
done