#!/bin/bash

set -euo pipefail

usage() {
  cat <<'EOF'
Usage: runSimulation.sh [--case simulationCases/SOME_CASE.c] [--input file.params]

Options:
  --case    Path to case source file (.c), optional.
  --input   Path to params file, optional.
  --help    Show this help.

Notes:
  - Defaults:
    --case  -> simulationCases/dropImpactVE.c
    --input -> default-VE.params
  - Default params are expected at repository root.
  - Compiles against src-local/ and runs in a per-case subdirectory.
EOF
}

SCRIPT_DIR=\$(cd "\$(dirname "\${BASH_SOURCE[0]}")" && pwd)
REPO_ROOT="\$SCRIPT_DIR"

resolve_file() {
  local candidate="\$1"
  if [ -f "\$candidate" ]; then
    echo "\$candidate"
  elif [ -f "\${REPO_ROOT}/\${candidate}" ]; then
    echo "\${REPO_ROOT}/\${candidate}"
  else
    echo ""
  fi
}

CASE_ARG="simulationCases/dropImpactVE.c"
INPUT_ARG=""

while [ "\$#" -gt 0 ]; do
  case "\$1" in
    --case)
      [ "\$#" -lt 2 ] && { echo "Missing value for --case"; usage; exit 1; }
      CASE_ARG="\$2"; shift 2 ;;
    --input)
      [ "\$#" -lt 2 ] && { echo "Missing value for --input"; usage; exit 1; }
      INPUT_ARG="\$2"; shift 2 ;;
    --help|-h)
      usage; exit 0 ;;
    *)
      echo "Unknown option: \$1"; usage; exit 1 ;;
  esac
done

CASE_FILE=\$(resolve_file "\$CASE_ARG")
[ -z "\$CASE_FILE" ] && { echo "Case source not found: \${CASE_ARG}"; exit 1; }

CASE_DIR=\$(cd "\$(dirname "\$CASE_FILE")" && pwd)
CASE_FILE_NAME=\$(basename "\$CASE_FILE")
CASE_NAME="\${CASE_FILE_NAME%.c}"
RUN_DIR="\${CASE_DIR}/\${CASE_NAME}"

if [ -n "\$INPUT_ARG" ]; then
  PARAM_SOURCE=\$(resolve_file "\$INPUT_ARG")
  [ -z "\$PARAM_SOURCE" ] && { echo "Parameter file not found: \${INPUT_ARG}"; exit 1; }
else
  PARAM_SOURCE="\${REPO_ROOT}/default-VE.params"
  [ ! -f "\$PARAM_SOURCE" ] && { echo "Default params not found: \${PARAM_SOURCE}"; exit 1; }
fi

mkdir -p "\$RUN_DIR"
cp "\$CASE_FILE" "\$RUN_DIR/"
PARAM_BASENAME=\$(basename "\$PARAM_SOURCE")
cp "\$PARAM_SOURCE" "\$RUN_DIR/\$PARAM_BASENAME"

cd "\$RUN_DIR"

qcc -I"\${REPO_ROOT}/src-local" -O2 -Wall \
  -disable-dimensions "\$CASE_FILE_NAME" -o "\$CASE_NAME" -lm

./"\$CASE_NAME" "\$PARAM_BASENAME"