#!/bin/bash
#SBATCH --job-name=burstingBubbleSweep
#SBATCH --nodes=1
#SBATCH --ntasks=48
#SBATCH --cpus-per-task=1
#SBATCH --time=100:00:00
#SBATCH --partition=genoa
#SBATCH --mail-type=ALL
#SBATCH [email protected]
#SBATCH --output=slurm-%j.out
#SBATCH --error=slurm-%j.err

# ============================================================
# Bursting Bubble - HPC Parameter Sweep Runner (Snellius)
# ============================================================
# This script runs Stage 2 (MPI simulation) on Snellius HPC.
#
# PREREQUISITE: Restart files must already exist for each case.
# Run Stage 1 locally before submitting:
#   ./runParameterSweep.sh --stage1-only sweep.params
#
# BEFORE RUNNING:
# 1. Run Stage 1 locally to generate restart files for all cases
# 2. Install Basilisk locally (creates basilisk/ and .project_config):
#    curl -sL https://raw.githubusercontent.com/comphy-lab/basilisk-C/main/reset_install_basilisk-ref-locked.sh | bash -s -- --ref=v2026-01-13
# 3. Edit sweep.params to set parameter ranges and case numbers
# 4. Adjust SBATCH parameters above (especially --ntasks, --time)
# 5. Submit with: sbatch runSweepSnellius.sbatch
#
# SBATCH Parameters to Customize:
#   --ntasks: Number of MPI tasks per case (currently 48)
#   --time: Wall time for entire sweep (currently 100 hours)
#   --partition: Compute partition (currently genoa)
#   --mail-user: Email for job notifications
# ============================================================

set -euo pipefail

# ============================================================
# Configuration
# ============================================================
# Use SLURM_SUBMIT_DIR (directory where sbatch was called) as the project root
SCRIPT_DIR="\${SLURM_SUBMIT_DIR:-\$(pwd)}"
SCRIPT_DIR="\$(cd "\$SCRIPT_DIR" && pwd)"
SWEEP_FILE="\${SCRIPT_DIR}/sweep.params"

# Source file to compile inside each case directory.
# Update for other cases (e.g., asymmetric coalescence) if needed.
SOURCE_FILE_NAME="burstingBubble.c"
EXECUTABLE_NAME="\${SOURCE_FILE_NAME%.c}"

# ============================================================
# Print Job Information
# ============================================================
echo "============================================="
echo "Bursting Bubble - HPC Parameter Sweep"
echo "============================================="
echo "Job started at: \$(date)"
echo "Running on node: \$(hostname)"
echo "Working directory: \$(pwd)"
echo "Job ID: \${SLURM_JOB_ID:-unknown}"
echo "Number of MPI tasks: \${SLURM_NTASKS:-unknown}"
echo "Partition: \${SLURM_JOB_PARTITION:-unknown}"
echo ""
echo "Mode: Stage 2 only (MPI simulation)"
echo "      Restart files must exist for each case"
echo ""

# ============================================================
# Load Required Modules
# ============================================================
echo "Loading modules..."
module purge
module load 2024
module load OpenMPI/5.0.3-GCC-13.3.0
echo "Modules loaded successfully"
echo ""

# ============================================================
# Setup Basilisk Environment
# ============================================================
echo "Setting up Basilisk environment..."
echo "Ensuring Basilisk is installed locally (ref v2026-01-13)..."
cd "\$SCRIPT_DIR"

if ! command -v curl >/dev/null 2>&1; then
  echo "ERROR: curl not found (required to install Basilisk)" >&2
  exit 1
fi

curl -sL https://raw.githubusercontent.com/comphy-lab/basilisk-C/main/reset_install_basilisk-ref-locked.sh | bash -s -- --ref=v2026-01-13

if [ -f "\${SCRIPT_DIR}/.project_config" ]; then
  # shellcheck disable=SC1090
  source "\${SCRIPT_DIR}/.project_config"
  echo "Basilisk environment loaded from .project_config"
  echo "BASILISK: \${BASILISK:-unset}"
else
  echo "ERROR: .project_config not found after Basilisk install" >&2
  exit 1
fi
echo ""

# ============================================================
# Validate Environment
# ============================================================
# Source parameter parsing library
if [ -f "\${SCRIPT_DIR}/src-local/parse_params.sh" ]; then
  # shellcheck disable=SC1091
  source "\${SCRIPT_DIR}/src-local/parse_params.sh"
else
  echo "ERROR: src-local/parse_params.sh not found" >&2
  exit 1
fi

# Check sweep file exists
if [ ! -f "\$SWEEP_FILE" ]; then
  echo "ERROR: Sweep file not found: \$SWEEP_FILE" >&2
  exit 1
fi

echo "Sweep file: \$SWEEP_FILE"
echo ""

# ============================================================
# Parse Sweep Configuration
# ============================================================
echo "Parsing sweep configuration..."

# Source the sweep file to get variables
# shellcheck disable=SC1090
source "\$SWEEP_FILE"

# Validate required variables
if [ -z "\${BASE_CONFIG:-}" ]; then
  echo "ERROR: BASE_CONFIG not defined in sweep file" >&2
  exit 1
fi

if [ -z "\${CASE_START:-}" ] || [ -z "\${CASE_END:-}" ]; then
  echo "ERROR: CASE_START and CASE_END must be defined in sweep file" >&2
  exit 1
fi

# Validate CaseNo range
if [ "\$CASE_START" -lt 1000 ] || [ "\$CASE_START" -gt 9999 ]; then
  echo "ERROR: CASE_START must be 4-digit (1000-9999), got: \$CASE_START" >&2
  exit 1
fi

if [ "\$CASE_END" -lt "\$CASE_START" ] || [ "\$CASE_END" -gt 9999 ]; then
  echo "ERROR: CASE_END must be >= CASE_START and <= 9999, got: \$CASE_END" >&2
  exit 1
fi

if [ ! -f "\$BASE_CONFIG" ]; then
  echo "ERROR: Base configuration file not found: \$BASE_CONFIG" >&2
  exit 1
fi

echo "Base configuration: \$BASE_CONFIG"
echo "Case number range: \$CASE_START to \$CASE_END"
echo ""

# ============================================================
# Extract Sweep Variables
# ============================================================
SWEEP_VARS=()
SWEEP_VALUES=()

# Read sweep file and extract SWEEP_* variables
while IFS='=' read -r key value; do
  # Skip comments and empty lines
  [[ "\${key:-}" =~ ^[[:space:]]*# ]] && continue
  [[ -z "\${key:-}" ]] && continue

  # Match SWEEP_* variables
  if [[ "\$key" =~ ^[[:space:]]*SWEEP_([^=]+) ]]; then
    var_name="\${BASH_REMATCH[1]}"
    # Remove inline comments and whitespace
    value=\$(echo "\${value:-}" | sed 's/#.*//' | xargs)

    SWEEP_VARS+=("\$var_name")
    SWEEP_VALUES+=("\$value")
  fi
done < "\$SWEEP_FILE"

if [ \${#SWEEP_VARS[@]} -eq 0 ]; then
  echo "ERROR: No SWEEP_* variables found in \$SWEEP_FILE" >&2
  exit 1
fi

echo "Sweep variables:"
for i in "\${!SWEEP_VARS[@]}"; do
  echo "  \${SWEEP_VARS[\$i]} = \${SWEEP_VALUES[\$i]}"
done
echo ""

# ============================================================
# Generate Parameter Combinations
# ============================================================
echo "Generating parameter combinations..."

# Create temporary directory for generated parameter files
# HPC note: Don't use /tmp - use local work directory instead
TEMP_DIR="\${SCRIPT_DIR}/.sweep_tmp_\$\$"
mkdir -p "\$TEMP_DIR" || {
  echo "ERROR: Failed to create temp directory: \$TEMP_DIR" >&2
  exit 1
}
trap 'rm -rf "\$TEMP_DIR"' EXIT

CASE_NUM=\$CASE_START
COMBINATION_COUNT=0
CASE_FILES=()

# Recursive function to generate all combinations
generate_combinations() {
  local depth=\$1
  shift
  local current_values=("\$@")

  if [ \$depth -eq \${#SWEEP_VARS[@]} ]; then
    # Base case: all variables assigned, create parameter file
    local case_file="\${TEMP_DIR}/case_\$(printf "%04d" "\$CASE_NUM").params"

    # Copy base config
    cp "\$BASE_CONFIG" "\$case_file"

    # Override CaseNo
    if grep -q "^CaseNo=" "\$case_file"; then
      sed -i'.bak' "s|^CaseNo=.*|CaseNo=\${CASE_NUM}|" "\$case_file"
    else
      echo "CaseNo=\${CASE_NUM}" >> "\$case_file"
    fi
    rm -f "\${case_file}.bak"

    # Override with sweep values
    for i in "\${!SWEEP_VARS[@]}"; do
      local var="\${SWEEP_VARS[\$i]}"
      local val="\${current_values[\$i]}"

      if grep -q "^\${var}=" "\$case_file"; then
        sed -i'.bak' "s|^\${var}=.*|\${var}=\${val}|" "\$case_file"
      else
        echo "\${var}=\${val}" >> "\$case_file"
      fi
      rm -f "\${case_file}.bak"
    done

    CASE_FILES+=("\$case_file")
    COMBINATION_COUNT=\$((COMBINATION_COUNT + 1))

    # Print summary
    echo "Case \$CASE_NUM:"
    for i in "\${!SWEEP_VARS[@]}"; do
      echo "  \${SWEEP_VARS[\$i]} = \${current_values[\$i]}"
    done
    echo ""

    CASE_NUM=\$((CASE_NUM + 1))
    return
  fi

  # Recursive case: iterate through values for current variable
  local values="\${SWEEP_VALUES[\$depth]}"
  IFS=',' read -r -a value_array <<< "\$values"

  for val in "\${value_array[@]}"; do
    val=\$(echo "\$val" | xargs)  # Trim whitespace
    generate_combinations \$((depth + 1)) "\${current_values[@]}" "\$val"
  done
}

# Start recursion
generate_combinations 0

echo "Generated \$COMBINATION_COUNT parameter combinations"

# Check if number of combinations matches the range
EXPECTED_COUNT=\$((CASE_END - CASE_START + 1))
if [ \$COMBINATION_COUNT -ne \$EXPECTED_COUNT ]; then
  echo "WARNING: Generated \$COMBINATION_COUNT combinations, but CASE_END suggests \$EXPECTED_COUNT" >&2
  echo "         Consider adjusting CASE_END in sweep file" >&2
fi

if [ \$COMBINATION_COUNT -gt \$EXPECTED_COUNT ]; then
  echo "ERROR: Too many combinations (\$COMBINATION_COUNT) for range \$CASE_START-\$CASE_END" >&2
  exit 1
fi

echo ""

# ============================================================
# Run Simulations (Stage 2 Only - MPI)
# ============================================================
echo "============================================="
echo "Running \$COMBINATION_COUNT Simulations"
echo "============================================="
echo "Stage 2 only: MPI simulation (\${SLURM_NTASKS:-unknown} tasks)"
echo "Requires existing restart files in each case directory"
echo ""

# Counters for tracking
SUCCESSFUL_CASES=0
FAILED_CASES=0
SKIPPED_CASES=0

for param_file in "\${CASE_FILES[@]}"; do
  # Parse parameter file to get values
  parse_param_file "\$param_file"
  CASE_NO=\$(get_param "CaseNo")
  Oh=\$(get_param "Oh" "1e-2")
  Bond=\$(get_param "Bond" "1e-3")
  MAXlevel=\$(get_param "MAXlevel" "10")
  tmax=\$(get_param "tmax" "1.0")
  zWall=\$(get_param "zWall" "0.025")

  if [ -z "\${CASE_NO:-}" ]; then
    echo "ERROR: CaseNo not found in \$param_file" >&2
    FAILED_CASES=\$((FAILED_CASES + 1))
    continue
  fi

  CASE_DIR="\${SCRIPT_DIR}/simulationCases/\${CASE_NO}"

  echo "========================================="
  echo "Case \$CASE_NO (\$(date))"
  echo "========================================="
  echo "Parameters: Oh=\$Oh, Bond=\$Bond"
  echo "            MAXlevel=\$MAXlevel, tmax=\$tmax, zWall=\$zWall"

  # Check if case directory exists
  if [ ! -d "\$CASE_DIR" ]; then
    echo "ERROR: Case directory not found: \$CASE_DIR" >&2
    echo "       Run Stage 1 locally first" >&2
    SKIPPED_CASES=\$((SKIPPED_CASES + 1))
    continue
  fi

  # Change to case directory
  cd "\$CASE_DIR"

  # Check for restart file (CRITICAL)
  if [ ! -f "restart" ]; then
    echo "ERROR: restart file not found for case \$CASE_NO" >&2
    echo "       Run Stage 1 locally first:" >&2
    echo "       ./runSimulation.sh --stage1 <params_file>" >&2
    SKIPPED_CASES=\$((SKIPPED_CASES + 1))
    cd "\$SCRIPT_DIR"
    continue
  fi

  echo "Found restart file"

  # Copy source file to case directory if needed
  SRC_FILE_ORIG="\${SCRIPT_DIR}/simulationCases/\${SOURCE_FILE_NAME}"
  SRC_FILE_LOCAL="\$CASE_DIR/\$SOURCE_FILE_NAME"

  if [ ! -f "\$SRC_FILE_ORIG" ]; then
    echo "ERROR: Source file \$SRC_FILE_ORIG not found" >&2
    FAILED_CASES=\$((FAILED_CASES + 1))
    cd "\$SCRIPT_DIR"
    continue
  fi

  cp "\$SRC_FILE_ORIG" "\$SRC_FILE_LOCAL"

  # Create symlink to DataFiles if needed
  if [ ! -e "DataFiles" ]; then
    ln -s ../DataFiles DataFiles
  fi

  # ============================================================
  # Stage 2: Full Simulation with MPI
  # ============================================================
  echo ""
  echo "Running Stage 2: Full simulation (MPI)..."

  # Compile with MPI
  if CC99='mpicc -std=c99 -D_GNU_SOURCE=1' qcc \
    -Wall -O2 -D_MPI=1 -disable-dimensions \
    "\$SOURCE_FILE_NAME" -o "\$EXECUTABLE_NAME" -lm 2>&1; then
    echo "MPI compilation successful"
  else
    echo "ERROR: MPI compilation failed for case \$CASE_NO" >&2
    FAILED_CASES=\$((FAILED_CASES + 1))
    cd "\$SCRIPT_DIR"
    continue
  fi

  # Run simulation with srun
  echo "Running full simulation with \${SLURM_NTASKS:-unknown} MPI tasks..."
  echo "Command: srun -n \${SLURM_NTASKS:-1} ./\$EXECUTABLE_NAME \$MAXlevel \$Oh \$Bond \$tmax \$zWall"
  echo ""

  if srun -n "\${SLURM_NTASKS:-1}" ./\$EXECUTABLE_NAME \$MAXlevel \$Oh \$Bond \$tmax \$zWall; then
    echo ""
    echo "Case \$CASE_NO completed successfully"
    SUCCESSFUL_CASES=\$((SUCCESSFUL_CASES + 1))
  else
    EXIT_CODE=\$?
    echo ""
    echo "ERROR: Case \$CASE_NO failed with exit code \$EXIT_CODE" >&2
    FAILED_CASES=\$((FAILED_CASES + 1))
  fi

  # Return to root directory
  cd "\$SCRIPT_DIR"
  echo ""
done

# ============================================================
# Final Summary
# ============================================================
echo "============================================="
echo "Parameter Sweep Complete"
echo "============================================="
echo "Job completed at: \$(date)"
echo "Total cases: \$COMBINATION_COUNT"
echo "Successful: \$SUCCESSFUL_CASES"
echo "Failed: \$FAILED_CASES"
echo "Skipped (no restart file): \$SKIPPED_CASES"
echo "Output location: simulationCases/"
echo "============================================="
echo ""

# Exit with error if any cases failed or were skipped
if [ \$FAILED_CASES -gt 0 ] || [ \$SKIPPED_CASES -gt 0 ]; then
  echo "WARNING: \$FAILED_CASES case(s) failed, \$SKIPPED_CASES case(s) skipped." >&2
  echo "         Check logs for details." >&2
  exit 1
fi

exit 0