#!/usr/bin/env bash

set -e -u -o pipefail -x

: ${MDBOOK:=mdbook}

TOPLEVEL=$(realpath $(dirname "$0"))/..
cd "${TOPLEVEL}"
./bin/reindex

./bin/make_redirects

# Now we deal with mermaid diagrams.
#
# This may require changes to the md files in {spec,proposals}
# or to the mdbook.toml files in mdbook/*/.
# We will make a copy of whatever we need to change,
# and then make changes to that copy.
#
# When we are done with these changes, we will set some variables:
# - HTML_OUTPUT_DIR is "", or the location where we have put our output.
# - MDBOOK_DIR is the parent directory of the possibly modified copies
#     of mdbook/{spec,proposals}.

if test -n "${MMDC:-}" || command -v "mmdc" >&/dev/null; then
    # CASE 1: mermaid-cli is installed.
    #
    # We will convert mermaid diagrams to svg.  The mermaid_cvt_svg
    # script does this with a temporary copy of our markdown directories,
    # so as not to alter the original.
    #
    # (The conversion involves npm and a headless chrome browser,
    # to it is understandable that not everybody would want to do it
    # this way.)

    TMPDIR=$(mktemp -d "${TOPLEVEL}/tmp_mmdc.XXXXXXXX")
    trap 'rm -rf "$TMPDIR"' 0
    ./bin/mermaid_cvt_svg "$TMPDIR"
    HTML_OUTPUT_DIR="$TMPDIR/html"
    MDBOOK_DIR="$TMPDIR/mdbook"
elif test -n "${MDBOOK_MERMAID:-}" || command -v "mdbook-mermaid" >&/dev/null; then
    # CASE 2: mdbook_mermaid is installed.
    #
    # We will make a temporary copy of the mdbook configuration directory
    # only, and use mdbook-mermaid to alter that.
    #
    # This is much easier to run locally, but it requires that your
    # browser has enough client-side javascript in order to run
    # mermaid.  It doesn't touch npm.
    MDBOOK_MERMAID=${MDBOOK_MERMAID:=mdbook-mermaid}
    TMPDIR=$(mktemp -d "${TOPLEVEL}/tmp_mdbook_mermaid.XXXXXXXX")
    trap 'rm -rf "$TMPDIR"' 0
    cp -r ./mdbook/proposals ./mdbook/spec ./mdbook/theme "$TMPDIR"
    mdbook-mermaid install "$TMPDIR/spec"
    mdbook-mermaid install "$TMPDIR/proposals"
    HTML_OUTPUT_DIR=""
    MDBOOK_DIR="$TMPDIR"
else
    # CASE 3: No mermaid support.
    #
    # In this case we run mdbook on our inputs unchanged.
    # The mermaid blocks will render as code.
    HTML_OUTPUT_DIR=""
    MDBOOK_DIR="$TOPLEVEL/mdbook"
fi

cd "${MDBOOK_DIR}/spec"
$MDBOOK build

cd "${MDBOOK_DIR}/proposals"
$MDBOOK build

if test -n "${HTML_OUTPUT_DIR}"; then
   rm -rf "${TOPLEVEL}/html"
   mv "${HTML_OUTPUT_DIR}" "${TOPLEVEL}/html"
fi