#!/usr/bin/env bash
set -euo pipefail

cd "$(dirname "$0")"

# LinuxCNC source basis: the wasm syntax probe compiles the
# linuxcnc-rs274-wasm-source-files.txt core entries with wasm-safe flags to
# catch browser-hostile LinuxCNC dependencies before link-time shimming.
linuxcnc_root=${LINUXCNC_ROOT:-../linuxcnc}
manifest=${1:-linuxcnc-rs274-wasm-source-files.txt}
cxx=${CXX:-g++}
if [[ -z ${CXX:-} ]] && command -v ccache >/dev/null 2>&1; then
    cxx="ccache $cxx"
fi
build_jobs=${CNC_SIM_BUILD_JOBS:-8}
if ! [[ "$build_jobs" =~ ^[1-9][0-9]*$ ]]; then
    echo "CNC_SIM_BUILD_JOBS must be a positive integer: $build_jobs" >&2
    exit 1
fi
build_dir=${CNC_SIM_WASM_SOURCE_SYNTAX_BUILD_DIR-build/wasm-source-syntax-test}
if [[ -z "$build_dir" ]]; then
    echo "CNC_SIM_WASM_SOURCE_SYNTAX_BUILD_DIR must not be empty" >&2
    exit 1
fi
if [[ "$build_dir" =~ [[:space:]] ]]; then
    echo "CNC_SIM_WASM_SOURCE_SYNTAX_BUILD_DIR must not contain whitespace: $build_dir" >&2
    exit 1
fi
mkdir -p "$build_dir"
build_dir=$(cd "$build_dir" && pwd)
if [[ "$build_dir" == "/" ]]; then
    echo "CNC_SIM_WASM_SOURCE_SYNTAX_BUILD_DIR must not be the filesystem root" >&2
    exit 1
fi
exec 9>"$build_dir/wasm-source-syntax.lock"
flock 9
preflight_cache_dir=${CNC_SIM_PREFLIGHT_CACHE_DIR:-"$build_dir/preflight-cache"}

LINUXCNC_ROOT="$linuxcnc_root" ./check-linuxcnc-inputs-cached.sh --cache-dir "$preflight_cache_dir" "$manifest"
manifest=$(cd "$(dirname "$manifest")" && pwd)/$(basename "$manifest")
linuxcnc_root=$(cd "$linuxcnc_root" && pwd)

common_flag_output=$(LINUXCNC_ROOT="$linuxcnc_root" ./list-linuxcnc-wasm-common-cxxflags.sh --profile core20 --syntax-only)
mapfile -t common_flags <<<"$common_flag_output"

source_list="$build_dir/linuxcnc_wasm_source_syntax_sources.txt"
CNC_SIM_PREFLIGHT_CACHE_DIR="$preflight_cache_dir" LINUXCNC_ROOT="$linuxcnc_root" ./list-linuxcnc-wasm-manifest-sources.sh "$manifest" core full > "$source_list"

wasm_source_syntax_signature="$build_dir/wasm-source-syntax.signature"
wasm_source_syntax_next_signature="$build_dir/wasm-source-syntax.signature.next"
{
    printf 'CXX=%s\n' "$cxx"
    printf 'PWD=%s\n' "$PWD"
    printf 'LINUXCNC_ROOT=%s\n' "$linuxcnc_root"
    printf 'MANIFEST=%s\n' "$manifest"
    printf 'BUILD_RULE_VERSION=1\n'
    printf 'COMMON_FLAGS='
    printf ' %s' "${common_flags[@]}"
    printf '\n'
    printf 'SOURCES:\n'
    cat "$source_list"
} > "$wasm_source_syntax_next_signature"
if [[ ! -f "$wasm_source_syntax_signature" ]] || ! cmp -s "$wasm_source_syntax_signature" "$wasm_source_syntax_next_signature"; then
    rm -f "$build_dir"/source_*.stamp "$build_dir"/source_*.d
fi
mv "$wasm_source_syntax_next_signature" "$wasm_source_syntax_signature"

wasm_source_syntax_makefile="$build_dir/wasm-source-syntax.mk"
{
    printf 'CXX := %s\n' "$cxx"
    printf 'COMMON_FLAGS :='
    printf ' %s' "${common_flags[@]}"
    printf '\n\n'
    printf 'STAMPS :=\n'
    source_index=0
    while IFS= read -r source; do
        [[ -z "$source" ]] && continue
        printf 'STAMPS += %s/source_%s.stamp\n' "$build_dir" "$source_index"
        source_index=$((source_index + 1))
    done < "$source_list"
    printf '\n.PHONY: all\n'
    printf 'all: $(STAMPS)\n\n'

    source_index=0
    while IFS= read -r source; do
        [[ -z "$source" ]] && continue
        printf '%s/source_%s.stamp: %s\n' "$build_dir" "$source_index" "$source"
        printf '\t@$(CXX) $(COMMON_FLAGS) -MMD -MP -MF %s/source_%s.d %s\n' "$build_dir" "$source_index" "$source"
        printf '\t@touch %s/source_%s.stamp\n\n' "$build_dir" "$source_index"
        source_index=$((source_index + 1))
    done < "$source_list"

    printf '%s' '-include'
    source_index=0
    while IFS= read -r source; do
        [[ -z "$source" ]] && continue
        printf ' %s/source_%s.d' "$build_dir" "$source_index"
        source_index=$((source_index + 1))
    done < "$source_list"
    printf '\n'
} > "$wasm_source_syntax_makefile"
make --output-sync=target -j"$build_jobs" -f "$wasm_source_syntax_makefile"

source_count=$(grep -c . "$source_list")
echo "linuxcnc wasm-safe source syntax probe passed ($source_count files)"