#!/usr/bin/env bash
# Documentation: serve the pages, and re-render the diagrams.
#
# Usage: docs.sh serve [port] | graphs [theme]
#
# The docs are a static SPA — index.html plus data/*.md read at runtime — so
# they need a server only because fetch() refuses file:// origins. Any static
# server does; python is already a hard dependency here (build.py is python), so
# there is no reason to reach for docker the way rig does.
set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(dirname "$SCRIPT_DIR")"
DOCS_DIR="$ROOT_DIR/docs"

PYTHON="${PYTHON:-python3}"
PORT="${DOCS_PORT:-8080}"

serve() {
    [ -n "${1:-}" ] && PORT="$1"
    if [ ! -f "$DOCS_DIR/index.html" ]; then
        echo "no docs/index.html" >&2
        exit 1
    fi
    echo "docs on http://localhost:${PORT}/"
    echo "  (ctrl-c to stop; nothing is installed and nothing persists)"
    cd "$DOCS_DIR"
    exec "$PYTHON" -m http.server "$PORT"
}

# Re-render docs/graphs/*.dot through every theme. The sources carry structure;
# the palette lives in docs/graphs/themes/*.gvpr. See docs/graphs/README.md.
graphs() {
    if [ ! -x "$DOCS_DIR/graphs/render.sh" ]; then
        echo "no docs/graphs/render.sh" >&2
        exit 1
    fi
    exec bash "$DOCS_DIR/graphs/render.sh" "$@"
}

case "${1:-serve}" in
    serve)       shift || true; serve "$@" ;;
    graphs)      shift || true; graphs "$@" ;;
    # `make docs 8090` is the obvious thing to type, so take it.
    ''|*[!0-9]*) echo "usage: $0 [serve [port]|graphs [theme]]" >&2; exit 1 ;;
    *)           serve "$1" ;;
esac