#!/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/dropImpact.c
    --input -> default-VE.params
  - If --input is not provided, defaults are used for:
    dropImpact -> default-VE.params
    dropImpact-EVP -> default-EVP.params
    dropImpact-EVP-HB -> default-EVP-HB.params
  - Default params are expected at repository root.
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
}

default_params_for_case() {
  case "\$1" in
    dropImpact)
      echo "default-VE.params"
      ;;
    dropImpact-EVP)
      echo "default-EVP.params"
      ;;
    dropImpact-EVP-HB)
      echo "default-EVP-HB.params"
      ;;
    *)
      echo ""
      ;;
  esac
}

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

while [ "\$#" -gt 0 ]; do
  case "\$1" in
    --case)
      if [ "\$#" -lt 2 ]; then
        echo "Missing value for --case"
        usage
        exit 1
      fi
      CASE_ARG="\$2"
      shift 2
      ;;
    --input)
      if [ "\$#" -lt 2 ]; then
        echo "Missing value for --input"
        usage
        exit 1
      fi
      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")
if [ -z "\$CASE_FILE" ]; then
  echo "Case source not found: \${CASE_ARG}"
  exit 1
fi

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}"

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

mkdir -p "\$RUN_DIR"
cp "\$CASE_FILE" "\$RUN_DIR/"

PARAM_BASENAME=""
if [ -n "\$PARAM_SOURCE" ]; then
  PARAM_BASENAME=\$(basename "\$PARAM_SOURCE")
  cp "\$PARAM_SOURCE" "\$RUN_DIR/\$PARAM_BASENAME"
fi

cd "\$RUN_DIR"

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

if [ -n "\$PARAM_BASENAME" ]; then
  ./"\$CASE_NAME" "\$PARAM_BASENAME"
else
  ./"\$CASE_NAME"
fi