#!/usr/bin/env bash
# Script to introspect bluez into specs/*.xml and generate src/*.rs from
# them.
#
# Introspection requires a running bluez daemon that is connected to devices
# with the features that you want to inspect. It also requires Bash >= 4 with
# associative array support. Bash >= 4 does not come with osx because of its
# GPLv3 license. Install it via homebrew.
## Set GDBUS='ssh pi@raspberrypi.local gdbus' to use remote gdbus.
## Set INTROSPECT=0 to skip introspection.
#
# Code generation requires dbus-codegen-rust.
# Install with `cargo install dbus-codegen`.
## Set GENERATE=0 to skip code generation.

set -euo pipefail

GDBUS=${GDBUS:-gdbus}
INTROSPECT=${INTROSPECT:-1}
GENERATE=${GENERATE:-1}

if [ $# != 0 ]; then
    echo "ERROR: $0 should be configured via the following environment variables:"
    echo
    grep '^## ' "$0" | sed 's/^## /  /'
    echo
    exit 1
fi

cd "$(dirname "$0")"

if [ "$INTROSPECT" = 1 ]; then
    $GDBUS introspect --system --dest org.bluez --object-path / --recurse \
        | grep -E '^ *(node|interface) .* {$' \
        | (
            declare -A interface_to_path

            while read -r keyword value _bracket; do
                if [ "$keyword" = 'node' ]; then
                    current_path=$value
                elif [ "$keyword" = 'interface' ]; then
                    interface_to_path[${value}]=$current_path
                else
                    echo "unexpected line $keyword $value $_bracket"
                    exit 1
                fi
            done

            for interface in "${!interface_to_path[@]}"; do
                [[ $interface == org.bluez* ]] || continue
                echo "$interface" -- "${interface_to_path[${interface}]}"
                $GDBUS introspect \
                    --system \
                    --dest=org.bluez \
                    --object-path="${interface_to_path[${interface}]}" \
                    --xml \
                    | xmllint --format - \
                    | grep -v '^ *<node name=".*"/>$' \
                        > "specs/$interface.xml"
            done
        )
fi

if [ "$GENERATE" = 1 ]; then
    echo "// Generated by introspect.sh" > src/lib.rs
    echo "#![allow(clippy::upper_case_acronyms, clippy::needless_borrow)]" >> src/lib.rs
    for file in specs/org.bluez.*.xml; do
        interface=$(
            echo "$file" \
                | sed -e 's:^specs/::' -e 's:[.]xml$::'
        )
        modname=$(
            echo "$interface" \
                | sed -e 's/^org.bluez.//' \
                | tr '[:upper:]' '[:lower:]'
        )
        dbus-codegen-rust \
            --file="$file" \
            --interfaces="$interface" \
            --client=nonblock \
            --methodtype=none \
            --prop-newtype \
            | grep -v '^use dbus as dbus;$' \
            | rustfmt \
            > "src/$modname.rs"
        echo "pub mod $modname;" >> src/lib.rs
        echo "pub use $modname::*;" >> src/lib.rs
    done
    cargo fmt
fi