#!/usr/bin/env bash
# Build the four books:  the user manual (docs/Manual.adoc, which ships inside the binary), the
# programming reference (docs/Reference.adoc), the Forge manual (docs/Forge.adoc), and the
# beginner's course (docs/Learn.adoc).  Produces .builddir/<Book>.html and .pdf for each, and then
# packs the three books that do not ship in the binary, with the lesson files and the licence, into
# .builddir/Singe-Docs-v<version>.zip, the optional documentation download.  The version comes from
# CMakeLists.txt.
#
#     ./build-docs.sh            the books as they ship
#     ./build-docs.sh preview    the same, with PREVIEW across every page, for proofreaders;  the
#                                download is then named -preview so it cannot be mistaken for a
#                                release, and the binary's own copy of the manual (rendered by
#                                CMake, not here) is never touched.
set -euo pipefail

here=$(cd "$(dirname "$0")" && pwd)
preview=
suffix=
if [[ "${1:-}" == "preview" ]]; then
    preview=1
    suffix=-preview
elif [[ -n "${1:-}" ]]; then
    echo "usage:  $0 [preview]" >&2
    exit 2
fi
src=$here/docs/Manual.adoc
forge=$here/docs/Forge.adoc
learn=$here/docs/Learn.adoc
ref=$here/docs/Reference.adoc

for doc in "$src" "$forge" "$learn" "$ref"; do
    if [[ ! -f $doc ]]; then
        echo "error: $doc not found" >&2
        exit 1
    fi
done
for tool in asciidoctor asciidoctor-pdf lua5.4 zip; do
    if ! command -v "$tool" > /dev/null; then
        echo "error: $tool not found (gem install asciidoctor asciidoctor-pdf rouge)" >&2
        exit 1
    fi
done

# The version, from the four numbers of the project() line:  patch 1 means a beta and tweak says
# which, so 3.00.1.2 is the books' "3.00b2", exactly as the binary is named.
read -r major minor patch tweak <<< "$(sed -n 's/^project(singe2 VERSION \([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\).*/\1 \2 \3 \4/p' "$here/CMakeLists.txt")"
if [[ $patch == 1 ]]; then
    version="${major}.${minor}b${tweak}"
else
    version="${major}.${minor}"
fi

# The watermark, when asked for:  a page background for the PDFs, a head snippet for the HTML.
pdfOpts=()
# The HTML pages carry their pictures inside them (data-uri), so a page is one file wherever it is
# copied and the download needs no images folder beside it.
htmlOpts=(-a data-uri)
if [[ -n $preview ]]; then
    pdfOpts=(-a "page-background-image=image:$here/docs/images/preview.svg[fit=fill]")
    htmlOpts+=(-a docinfo=shared -a "docinfodir=$here/docs/preview")
fi

out=$here/.builddir
mkdir -p "$out"
# The Forge vocabulary tables come from the manifest itself, so the manual cannot drift from it.
lua5.4 "$here/util/forgeVocabulary.lua" > "$here/docs/ForgeVocabulary.adoc"
asciidoctor ${htmlOpts[@]+"${htmlOpts[@]}"} -a revnumber="$version" "$src" -o "$out/Manual.html"
asciidoctor-pdf ${pdfOpts[@]+"${pdfOpts[@]}"} -a revnumber="$version" "$src" -o "$out/Manual.pdf"
asciidoctor ${htmlOpts[@]+"${htmlOpts[@]}"} -a revnumber="$version" "$forge" -o "$out/Forge.html"
asciidoctor-pdf ${pdfOpts[@]+"${pdfOpts[@]}"} -a revnumber="$version" "$forge" -o "$out/Forge.pdf"
asciidoctor ${htmlOpts[@]+"${htmlOpts[@]}"} -a revnumber="$version" "$learn" -o "$out/Learn.html"
asciidoctor-pdf ${pdfOpts[@]+"${pdfOpts[@]}"} -a revnumber="$version" "$learn" -o "$out/Learn.pdf"
asciidoctor ${htmlOpts[@]+"${htmlOpts[@]}"} -a revnumber="$version" "$ref" -o "$out/Reference.html"
asciidoctor-pdf ${pdfOpts[@]+"${pdfOpts[@]}"} -a revnumber="$version" "$ref" -o "$out/Reference.pdf"

# The documentation download:  everything but the user manual, which the binary carries.  Built in
# a staging folder so the zip has one top-level directory and no stray build files.
stage=$out/Singe-Docs-v$version$suffix
rm -rf "$stage" "$stage.zip"
mkdir -p "$stage/learn"
cp "$out/Reference.pdf" "$out/Reference.html" "$out/Forge.pdf" "$out/Forge.html" "$out/Learn.pdf" "$out/Learn.html" "$stage/"
cp -r "$here/docs/learn/." "$stage/learn/"
cp "$here/COPYING" "$stage/"
cat > "$stage/README.txt" <<EOF
Singe $version documentation

  Reference.pdf / .html   Everything a game can do:  the programming model and every function.
  Learn.pdf / .html       Learn to Program with Singe:  thirty lessons from nothing to a finished game.
  Forge.pdf / .html       Forge, the authoring tool:  ten tutorials and the vocabulary.
  learn/                  The finished script of every lesson, and the art kit the lessons use.
  COPYING                 The licence, GPL version 3.

The user manual, Manual.pdf, is inside Singe itself and is unpacked into the Singe folder the first
time it runs.  Forge is a separate download.
EOF
(cd "$out" && zip -q -r "Singe-Docs-v$version$suffix.zip" "Singe-Docs-v$version$suffix")
rm -rf "$stage"

echo "built:"
ls -la "$out/Manual.html" "$out/Manual.pdf" "$out/Reference.html" "$out/Reference.pdf" "$out/Forge.html" "$out/Forge.pdf" "$out/Learn.html" "$out/Learn.pdf" "$out/Singe-Docs-v$version$suffix.zip"