// Copyright 2019 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"context"
	"fmt"
	"sync/atomic"

	"github.com/pingcap/tidb/plugin"
	"github.com/pingcap/tidb/sessionctx/variable"
)

// Accumulator of connection
// It can be increased by 1 after each OnConnectionEvent is triggered.
var connection int32

// Validate implements TiDB plugin's Validate SPI.
func Validate(ctx context.Context, m *plugin.Manifest) error {
	fmt.Println("## conn_ip_example Validate called ##")
	fmt.Printf("---- context: %s\n", ctx)
	fmt.Printf("---- read cfg in validate [key: conn_ip_example_key, value: %s]\n", m.SysVars["conn_ip_example_key"].Value)
	return nil
}

// OnInit implements TiDB plugin's OnInit SPI.
func OnInit(ctx context.Context, manifest *plugin.Manifest) error {
	fmt.Println("## conn_ip_example OnInit called ##")
	fmt.Printf("---- context: %s\n", ctx)
	fmt.Printf("---- read cfg in init [key: conn_ip_example_key, value: %s]\n", manifest.SysVars["conn_ip_example_key"].Value)
	atomic.SwapInt32(&connection, 0)
	return nil
}

// OnShutdown implements TiDB plugin's OnShutdown SPI.
func OnShutdown(ctx context.Context, manifest *plugin.Manifest) error {
	fmt.Println("## conn_ip_examples OnShutdown called ##")
	fmt.Printf("---- context: %s\n", ctx)
	fmt.Printf("---- read cfg in shutdown [key: conn_ip_example_key, value: %s]\n", manifest.SysVars["conn_ip_example_key"].Value)
	atomic.SwapInt32(&connection, 0)
	return nil
}

// OnGeneralEvent implements TiDB Audit plugin's OnGeneralEvent SPI.
func OnGeneralEvent(ctx context.Context, sctx *variable.SessionVars, event plugin.GeneralEvent, cmd string) {
	fmt.Println("## conn_ip_example OnGeneralEvent called ##")
	fmt.Printf("---- new connection by %s\n", ctx.Value("ip"))
	if sctx != nil {
		fmt.Printf("---- session status: %d\n", sctx.Status)
	}
	switch event {
	case plugin.Log:
		fmt.Println("---- event: Log")
	case plugin.Error:
		fmt.Println("---- event: Error")
	case plugin.Result:
		fmt.Println("---- event: Result")
	case plugin.Status:
		fmt.Println("---- event: Status")
	default:
		fmt.Println("---- event: unrecognized")
	}
	fmt.Printf("---- cmd: %s\n", cmd)
}

// OnConnectionEvent implements TiDB Audit plugin's OnConnectionEvent SPI.
func OnConnectionEvent(ctx context.Context, event plugin.ConnectionEvent, info *variable.ConnectionInfo) error {
	var reason string
	if r := ctx.Value(plugin.RejectReasonCtxValue{}); r != nil {
		reason = r.(string)
	}
	fmt.Println("## conn_ip_example onConnectionEvent called ##")
	fmt.Printf("---- conenct event: %s, reason: [%s]\n", event, reason)
	fmt.Printf("---- connection host: %s\n", info.Host)
	atomic.AddInt32(&connection, 1)
	return nil
}