#!/bin/bash

# ===========================================
# 学生状态变更处理服务健康检查脚本
# 用于监控服务运行状态和数据库连接
# ===========================================

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIG_FILE="${SCRIPT_DIR}/data.conf"
CONTROL_SCRIPT="${SCRIPT_DIR}/control_scripts.sh"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Load configuration
if [[ ! -f "$CONFIG_FILE" ]]; then
    echo -e "${RED}错误：配置文件 $CONFIG_FILE 未找到！${NC}"
    exit 1
fi

source "$CONFIG_FILE"

# Functions
log() {
    local level="$1"
    local message="$2"
    local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
    echo -e "${timestamp} [$level] $message"
}

success() {
    echo -e "${GREEN}✓ $1${NC}"
}

error() {
    echo -e "${RED}✗ $1${NC}"
}

warning() {
    echo -e "${YELLOW}⚠ $1${NC}"
}

info() {
    echo -e "${BLUE}ℹ $1${NC}"
}

# 检查数据库连接
check_database() {
    info "正在检查数据库连接..."

    local db_test
    if db_test=$(mysql -h"$DB_HOST" -P"$DB_PORT" -u"$DB_USER" -p"$DB_PASS" "$DB_NAME" -e "SELECT 1 as test;" 2>/dev/null); then
        if echo "$db_test" | grep -q "test"; then
            success "数据库连接成功"
            return 0
        else
            error "数据库查询失败"
            return 1
        fi
    else
        error "数据库连接失败"
        return 1
    fi
}

# 检查服务状态
check_service() {
    local service_name="$1"
    local service_desc="$2"

    info "正在检查 $service_desc..."

    if [[ ! -x "$CONTROL_SCRIPT" ]]; then
        error "控制脚本未找到或不可执行: $CONTROL_SCRIPT"
        return 1
    fi

    local status_output
    status_output=$("$CONTROL_SCRIPT" status "$service_name" 2>/dev/null)

    if echo "$status_output" | grep -q "is running"; then
        success "$service_desc 正在运行"

        # 提取PID（如果可用）
        local pid
        pid=$(echo "$status_output" | grep -o "PID: [0-9]*" | cut -d' ' -f2)
        if [[ -n "$pid" ]]; then
            info "  进程ID: $pid"
        fi

        return 0
    else
        error "$service_desc 未运行"
        return 1
    fi
}

# 检查日志文件
check_logs() {
    info "正在检查日志文件..."

    if [[ ! -d "$LOG_DIR" ]]; then
        warning "日志目录不存在: $LOG_DIR"
        return 1
    fi

    # 统计日志文件数量
    local log_count
    log_count=$(find "$LOG_DIR" -name "*.log" -type f | wc -l)

    if [[ $log_count -gt 0 ]]; then
        success "发现 $log_count 个日志文件"

        # 检查最近的错误
        local recent_errors
        recent_errors=$(find "$LOG_DIR" -name "*.log" -type f -mmin -60 -exec grep -l "ERROR" {} \; | wc -l)

        if [[ $recent_errors -gt 0 ]]; then
            warning "发现 $recent_errors 个日志文件包含最近的错误 (最近60分钟)"
        else
            info "日志文件中未发现最近的错误"
        fi

        return 0
    else
        warning "未发现日志文件"
        return 1
    fi
}

# 检查待处理记录
check_pending_records() {
    info "正在检查数据库中的待处理记录..."

    local pending_changes pending_resume

    # Check changes (XIU_XUE, TUI_XUE, BI_YE)
    pending_changes=$(mysql -h"$DB_HOST" -P"$DB_PORT" -u"$DB_USER" -p"$DB_PASS" "$DB_NAME" -e "
        SELECT COUNT(*) as count FROM xg_student_status_change
        WHERE process_status = 0
        AND change_type IN ('XIU_XUE', 'TUI_XUE', 'BI_YE')
        AND deleted = 0;
    " 2>/dev/null | tail -n1)

    # Check resume (FU_XUE)
    pending_resume=$(mysql -h"$DB_HOST" -P"$DB_PORT" -u"$DB_USER" -p"$DB_PASS" "$DB_NAME" -e "
        SELECT COUNT(*) as count FROM xg_student_status_change
        WHERE process_status = 0
        AND change_type = 'FU_XUE'
        AND deleted = 0;
    " 2>/dev/null | tail -n1)

    # Remove potential header
    pending_changes=$(echo "$pending_changes" | grep -E '^[0-9]+$')
    pending_resume=$(echo "$pending_resume" | grep -E '^[0-9]+$')

    if [[ -z "$pending_changes" ]]; then
        pending_changes="0"
    fi

    if [[ -z "$pending_resume" ]]; then
        pending_resume="0"
    fi

    local total_pending=$((pending_changes + pending_resume))

    if [[ $total_pending -gt 0 ]]; then
        info "发现 $total_pending 条待处理记录 ($pending_changes 条变更, $pending_resume 条复学)"
        if [[ $pending_changes -gt 0 ]]; then
            warning "  $pending_changes 条记录等待变更处理"
        fi
        if [[ $pending_resume -gt 0 ]]; then
            warning "  $pending_resume 条记录等待复学处理"
        fi
    else
        success "未发现待处理记录"
    fi

    return 0
}

# 检查磁盘空间
check_disk_space() {
    info "正在检查磁盘空间..."

    local log_disk_usage
    log_disk_usage=$(df "$LOG_DIR" 2>/dev/null | tail -n1 | awk '{print $5}' | sed 's/%//')

    if [[ -z "$log_disk_usage" ]]; then
        warning "无法确定日志目录的磁盘使用情况"
        return 1
    fi

    if [[ $log_disk_usage -gt 90 ]]; then
        error "日志目录磁盘使用率达到 ${log_disk_usage}% - 建议清理旧日志"
        return 1
    elif [[ $log_disk_usage -gt 75 ]]; then
        warning "日志目录磁盘使用率达到 ${log_disk_usage}%"
    else
        success "日志目录磁盘使用率 ${log_disk_usage}%"
    fi

    return 0
}

# Generate health report
generate_report() {
    local report_file="${LOG_DIR}/health_check_$(date +%Y%m%d_%H%M%S).log"

    {
        echo "=== 学生状态变更处理服务健康检查报告 ==="
        echo "检查时间: $(date)"
        echo "检查主机: $(hostname)"
        echo ""

        echo "=== 数据库连接检查 ==="
        if check_database; then
            echo "状态: 正常"
        else
            echo "状态: 异常"
        fi
        echo ""

        echo "=== 服务状态检查 ==="
        echo "学生状态变更处理服务 (休学/退学/毕业):"
        if check_service "changes" "学生状态变更处理服务"; then
            echo "状态: 运行中"
        else
            echo "状态: 未运行"
        fi

        echo "学生复学处理服务:"
        if check_service "resume" "学生复学处理服务"; then
            echo "状态: 运行中"
        else
            echo "状态: 未运行"
        fi
        echo ""

        echo "=== 待处理记录检查 ==="
        check_pending_records
        echo ""

        echo "=== 日志文件检查 ==="
        check_logs
        echo ""

        echo "=== 磁盘空间检查 ==="
        check_disk_space
        echo ""

        echo "=== 配置信息 ==="
        echo "数据库主机: $DB_HOST:$DB_PORT"
        echo "数据库名称: $DB_NAME"
        echo "日志目录: $LOG_DIR"
        echo "脚本目录: $SCRIPT_DIR"
        echo ""

        echo "报告生成完成"

    } > "$report_file" 2>/dev/null

    if [[ -f "$report_file" ]]; then
        success "健康检查报告已生成: $report_file"
    else
        error "生成健康检查报告失败"
    fi
}

# Main function
main() {
    local generate_report="${1:-false}"

    echo ""
    echo "========================================"
    echo "    学生状态变更处理服务健康检查"
    echo "========================================"
    echo ""

    # Perform all checks
    check_database
    echo ""

    check_service "changes" "学生状态变更处理服务 (休学/退学/毕业)"
    check_service "resume" "学生复学处理服务"
    echo ""

    check_pending_records
    echo ""

    check_logs
    echo ""

    check_disk_space
    echo ""

    # Generate report if requested
    if [[ "$generate_report" == "report" ]]; then
        generate_report
    fi

    echo ""
    echo "========================================"
    success "健康检查完成"
    echo ""

    if [[ "$generate_report" == "report" ]]; then
        echo "详细报告已保存到日志目录"
    fi

    echo "使用方法："
    echo "  $0              # 执行健康检查"
    echo "  $0 report       # 执行检查并生成报告"
    echo ""
}

# 显示使用方法
show_usage() {
    cat << EOF
用法: $0 [report]

执行学生状态变更处理服务的健康检查。

选项:
    report   生成详细的健康检查报告

检查内容：
- 数据库连接状态
- 服务运行状态
- 待处理记录数量
- 日志文件状态
- 磁盘空间使用情况

EOF
}

# Parse arguments
case "${1:-}" in
    report)
        main "report"
        ;;
    -h|--help)
        show_usage
        ;;
    "")
        main
        ;;
    *)
        error "未知选项: $1"
        show_usage
        exit 1
        ;;
esac