#!/bin/bash
# run_parallel.sh — 通用并行运行 OpenFOAM case
# 用法: bash run_parallel.sh <cases_dir> [n_parallel] [n_procs_per_case]
# 参数:
#   cases_dir         — 包含 t00/, t01/, ... 子目录的 case 根目录
#   n_parallel        — 并行运行的 case 数（默认 8）
#   n_procs_per_case  — 每个 case 的 MPI 进程数（默认 4）
#
# 示例:
#   bash run_parallel.sh /home/alanz/openfoam-workspace/output/data/rising_bubble 8 4
#   bash run_parallel.sh /home/alanz/openfoam-workspace/output/data/dam_break 4 1
#   bash run_parallel.sh /home/alanz/openfoam-workspace/output/data/droplet_impact 8 4

set -o pipefail

CASES_DIR="${1:?用法: bash run_parallel.sh <cases_dir> [n_parallel] [n_procs_per_case]}"
N_PARALLEL="${2:-8}"
N_PROCS="${3:-4}"
SCRIPTS_DIR="$(cd "$(dirname "$0")" && pwd)"
LOG_DIR="$CASES_DIR/batch_logs"

mkdir -p "$LOG_DIR"

# 发现所有 case 目录
CASE_DIRS=()
for d in "$CASES_DIR"/t[0-9]*; do
    [ -d "$d" ] && [ -f "$d/Allrun" ] && CASE_DIRS+=("$d")
done

TOTAL=${#CASE_DIRS[@]}
CASE_TYPE=$(basename "$CASES_DIR")
echo "=== $CASE_TYPE 并行运行 ==="
echo "总 case 数: $TOTAL"
echo "并行数: $N_PARALLEL"
echo "每 case MPI 进程: $N_PROCS"
echo "开始时间: $(date)"
echo ""

if [ "$TOTAL" -eq 0 ]; then
    echo "WARNING: 未发现任何 case 目录（含 Allrun），检查 $CASES_DIR"
    exit 0
fi

SUCCESS=0
FAILED=0

# 追踪后台进程（索引数组，兼容 set -u）
RUN_PIDS=()
RUN_CASES=()

run_case() {
    local case_dir="$1"
    local case_name
    case_name=$(basename "$case_dir")
    local log_file="$LOG_DIR/${case_name}.log"

    echo "[$(date +%H:%M:%S)] 启动: $case_name"
    bash "$SCRIPTS_DIR/run_case.sh" "$case_dir" "$N_PROCS" > "$log_file" 2>&1
    return $?
}

cleanup() {
    echo ""
    echo "收到终止信号，等待正在运行的 case 完成..."
    for pid in "${RUN_PIDS[@]+"${RUN_PIDS[@]}"}"; do
        wait "$pid" 2>/dev/null
    done
    echo "所有进程已结束"
    exit 0
}
trap cleanup SIGINT SIGTERM

reap_finished() {
    local active_pids=()
    local active_cases=()
    for j in "${!RUN_PIDS[@]}"; do
        local pid="${RUN_PIDS[$j]}"
        if ! kill -0 "$pid" 2>/dev/null; then
            wait "$pid"
            local exit_code=$?
            local finished_case="${RUN_CASES[$j]}"
            if [ "$exit_code" -eq 0 ]; then
                echo "[$(date +%H:%M:%S)] 完成: $finished_case"
                SUCCESS=$((SUCCESS + 1))
            else
                echo "[$(date +%H:%M:%S)] FAILED: $finished_case (exit=$exit_code)"
                FAILED=$((FAILED + 1))
            fi
        else
            active_pids+=("$pid")
            active_cases+=("${RUN_CASES[$j]}")
        fi
    done
    RUN_PIDS=("${active_pids[@]+"${active_pids[@]}"}")
    RUN_CASES=("${active_cases[@]+"${active_cases[@]}"}")
}

for i in "${!CASE_DIRS[@]}"; do
    case_dir="${CASE_DIRS[$i]}"
    case_name=$(basename "$case_dir")
    idx=$((i + 1))

    # 等待直到有空闲 slot
    while [ "${#RUN_PIDS[@]}" -ge "$N_PARALLEL" ]; do
        reap_finished
        [ "${#RUN_PIDS[@]}" -ge "$N_PARALLEL" ] && sleep 1
    done

    run_case "$case_dir" &
    bg_pid=$!
    RUN_PIDS+=("$bg_pid")
    RUN_CASES+=("$case_name")
    echo "[$(date +%H:%M:%S)] [$idx/$TOTAL] 已提交: $case_name (pid=$bg_pid)"
done

# 等待所有剩余进程
echo ""
echo "所有 case 已提交，等待完成..."
for j in "${!RUN_PIDS[@]}"; do
    pid="${RUN_PIDS[$j]}"
    wait "$pid"
    exit_code=$?
    finished_case="${RUN_CASES[$j]}"
    if [ "$exit_code" -eq 0 ]; then
        echo "[$(date +%H:%M:%S)] 完成: $finished_case"
        SUCCESS=$((SUCCESS + 1))
    else
        echo "[$(date +%H:%M:%S)] FAILED: $finished_case (exit=$exit_code)"
        FAILED=$((FAILED + 1))
    fi
done

echo ""
echo "=== $CASE_TYPE 批量运行完成 ==="
echo "总计: $TOTAL, 成功: $SUCCESS, 失败: $FAILED"
echo "结束时间: $(date)"
echo "日志目录: $LOG_DIR"

if [ "$FAILED" -gt 0 ]; then
    echo ""
    echo "失败 case 列表:"
    for log in "$LOG_DIR"/*.log; do
        [ -f "$log" ] || continue
        case_name=$(basename "$log" .log)
        if grep -q "ERROR" "$log" 2>/dev/null; then
            echo "  $case_name"
        fi
    done
fi