#!/usr/bin/env bash
#
# Build and run the Vitis HLS C-simulation for a practical, locally.
#
# This is a plain C++ compile of the testbench + DUT, which is what "Run C
# Simulation" does on the server (minus the HLS compiler's extra checking).
# It is the fast way to know your logic is right before spending time on the
# remote machine.
#
# Usage:
#   ./sim.sh                              # practical-3b
#   ./sim.sh practical-4                  # any other practical directory
#
set -euo pipefail

here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
practical="${1:-practical-3b}"

# Find the HLS component: the directory holding hls_config.cfg.
cfg="$(find "$here/../$practical" -name hls_config.cfg -not -path '*/hls/*' 2>/dev/null | head -1)"
if [ -z "$cfg" ]; then
    echo "error: no hls_config.cfg found under $here/../$practical" >&2
    exit 1
fi
proj="$(cd "$(dirname "$cfg")" && pwd)"

# hls_config.cfg names the sources, so we never have to guess.
tb_name="$(grep -E '^tb\.file='  "$cfg" | head -1 | cut -d= -f2- | tr -d '\r')"
dut_name="$(grep -E '^syn\.file=' "$cfg" | grep -E '\.(cpp|cc|cxx|c)$' | head -1 | cut -d= -f2- | tr -d '\r')"

if [ -z "$tb_name" ] || [ -z "$dut_name" ]; then
    echo "error: could not read tb.file / syn.file from $cfg" >&2
    exit 1
fi

# Prefer the real Xilinx headers; fall back to the stub so this still works
# before ./fetch-headers.sh has been run.
if [ -f "$here/include/ap_int.h" ]; then
    inc="$here/include"
    inc_extra="$here/include"
else
    inc="$here/include-stub"
    inc_extra="$here/include-stub"
    echo "=============================================================="
    echo "NOTE: using the FALLBACK stub headers in hlsdev/include-stub."
    echo "      They are good enough for the Game of Life practical, but"
    echo "      they are NOT the real Xilinx headers. Run ./fetch-headers.sh"
    echo "      for a simulation you can fully trust."
    echo "=============================================================="
    echo
fi

CXX="${CXX:-clang++}"
out="$here/build"
mkdir -p "$out"

dut="$proj/$dut_name"
tb="$proj/$tb_name"
for f in "$dut" "$tb"; do
    [ -f "$f" ] || { echo "error: missing source $f" >&2; exit 1; }
done

echo "component : $proj"
echo "testbench : $tb_name"
echo "dut       : $dut_name"
echo "compiling with $CXX ..."

"$CXX" -std=c++14 -O2 -Wall -Wextra -Wno-unknown-pragmas -Wno-unused-label \
    -I"$inc" -I"$inc_extra" -I"$proj" \
    "$tb" "$dut" -o "$out/csim"

echo "running ..."
echo "------------------------------------------------------------------"
"$out/csim"
echo "------------------------------------------------------------------"