#!/bin/bash

# ===========================================
# 学生状态变更处理脚本 - 复学
# 处理类型: FU_XUE(复学)
# ===========================================

set -euo pipefail

# Load configuration
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIG_FILE="${SCRIPT_DIR}/data.conf"

if [[ ! -f "$CONFIG_FILE" ]]; then
    echo "Error: Configuration file $CONFIG_FILE not found!"
    exit 1
fi

source "$CONFIG_FILE"

# Create log directory
mkdir -p "$LOG_DIR"

# Log file
LOG_FILE="${LOG_DIR}/process_student_resume_$(date +%Y%m%d_%H%M%S).log"

# Lock file to prevent multiple instances
LOCK_FILE="${SCRIPT_DIR}/process_student_resume.lock"

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

error_exit() {
    local message="$1"
    log "ERROR" "$message"
    # Remove lock file
    [[ -f "$LOCK_FILE" ]] && rm -f "$LOCK_FILE"
    exit 1
}

# Check if script is already running
if [[ -f "$LOCK_FILE" ]]; then
    if kill -0 $(cat "$LOCK_FILE") 2>/dev/null; then
        log "INFO" "Script is already running (PID: $(cat "$LOCK_FILE"))"
        exit 1
    else
        log "WARN" "Removing stale lock file"
        rm -f "$LOCK_FILE"
    fi
fi

# Create lock file
echo $$ > "$LOCK_FILE"

# Cleanup function
cleanup() {
    [[ -f "$LOCK_FILE" ]] && rm -f "$LOCK_FILE"
    log "INFO" "Script execution completed"
}

trap cleanup EXIT

# Database functions
execute_sql() {
    local sql="$1"
    local result

    result=$(mysql -h"$DB_HOST" -P"$DB_PORT" -u"$DB_USER" -p"$DB_PASS" "$DB_NAME" -e "$sql" 2>&1)
    local exit_code=$?

    if [[ $exit_code -ne 0 ]]; then
        log "ERROR" "SQL execution failed: $sql"
        log "ERROR" "MySQL error: $result"
        return 1
    fi

    echo "$result"
}

# Process student resume
process_student_resume() {
    local record_id="$1"
    local student_id="$2"
    local student_no="$3"
    local change_type="$4"
    local operator_id="${5:-1}"

    log "INFO" "Processing student resume - ID: $record_id, Student: $student_no ($student_id), Type: $change_type"

    # Start transaction
    local transaction_sql="
    START TRANSACTION;

    -- 1. Backup original data to his tables
    INSERT INTO xg_student_msg_his SELECT * FROM xg_student_msg WHERE id = $student_id;
    INSERT INTO sys_user_his SELECT * FROM sys_user WHERE user_id = $student_id;

    -- 2. Update student status to resume (复学)
    UPDATE xg_student_msg SET
        student_status = '3',
        update_by = $operator_id,
        update_time = NOW()
    WHERE id = $student_id;

    -- 3. Enable user account
    UPDATE sys_user SET
        status = '0',
        update_by = $operator_id,
        update_time = NOW()
    WHERE user_id = $student_id AND account_type = '2';

    -- 4. Update change record status
    UPDATE xg_student_status_change SET
        process_status = 1,
        update_by = $operator_id,
        update_time = NOW()
    WHERE id = $record_id;

    COMMIT;
    "

    # Execute transaction
    if execute_sql "$transaction_sql"; then
        log "INFO" "Successfully processed student resume - ID: $record_id, Student: $student_no"
        return 0
    else
        log "ERROR" "Failed to process student resume - ID: $record_id, Student: $student_no"
        return 1
    fi
}

# Main function
main() {
    log "INFO" "Starting student resume processing daemon"
    log "INFO" "Processing type: FU_XUE(复学)"
    log "INFO" "Running in continuous mode with 10-minute intervals"

    # Test database connection
    log "INFO" "Testing database connection..."
    if ! execute_sql "SELECT 1;" >/dev/null 2>&1; then
        error_exit "Database connection failed"
    fi
    log "INFO" "Database connection successful"

    # Main processing loop
    while true; do
        log "INFO" "Starting new resume processing cycle"

        # Get unprocessed records
        local query_sql="
        SELECT id, student_id, student_no, change_type, operator_id
        FROM xg_student_status_change
        WHERE process_status = 0
      AND change_type = 'FU_XUE'
      AND deleted = 0
        ORDER BY create_time ASC
        LIMIT $BATCH_SIZE;
        "

        local records
        records=$(execute_sql "$query_sql")

        # Check if there are records to process
        local record_count
        record_count=$(echo "$records" | wc -l)

        if [[ $record_count -le 1 ]]; then
            log "INFO" "No unprocessed resume records found, waiting..."
        else
            # Remove header line
            records=$(echo "$records" | tail -n +2)

            local processed_count=0
            local failed_count=0

            # Process each record
            while IFS=$'\t' read -r record_id student_id student_no change_type operator_id; do
                # Skip empty lines
                [[ -z "$record_id" ]] && continue

                local retry_count=0
                local success=false

                while [[ $retry_count -lt $MAX_RETRY && $success == false ]]; do
                    if process_student_resume "$record_id" "$student_id" "$student_no" "$change_type" "$operator_id"; then
                        success=true
                        ((processed_count++))
                    else
                        ((retry_count++))
                        if [[ $retry_count -lt $MAX_RETRY ]]; then
                            log "WARN" "Processing failed, retrying in $RETRY_DELAY seconds... (attempt $retry_count/$MAX_RETRY)"
                            sleep $RETRY_DELAY
                        fi
                    fi
                done

                if [[ $success == false ]]; then
                    ((failed_count++))
                    log "ERROR" "Failed to process record after $MAX_RETRY attempts - ID: $record_id"
                fi

            done <<< "$records"

            log "INFO" "Resume processing cycle completed - Processed: $processed_count, Failed: $failed_count"
        fi

        # Wait for configured interval before next cycle
        log "INFO" "Waiting $CYCLE_INTERVAL seconds before next resume processing cycle..."
        sleep $CYCLE_INTERVAL
    done
}

# Run main function
main "$@"