// Copyright 2020 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 ansible

import (
	"fmt"
	"strings"
	"time"

	"github.com/pingcap-incubator/tiup-cluster/pkg/executor"
	"github.com/pingcap-incubator/tiup-cluster/pkg/log"
	"github.com/pingcap-incubator/tiup-cluster/pkg/meta"
	"github.com/pingcap/errors"
)

var (
	systemdUnitPath = "/etc/systemd/system"
)

// parseDirs sets values of directories of component
func parseDirs(user string, ins meta.InstanceSpec, sshTimeout int64) (meta.InstanceSpec, error) {
	hostName, sshPort := ins.SSH()

	e := executor.NewSSHExecutor(executor.SSHConfig{
		Host:    hostName,
		Port:    sshPort,
		User:    user,
		KeyFile: SSHKeyPath(), // ansible generated keyfile
		Timeout: time.Second * time.Duration(sshTimeout),
	}, false) // not using global sudo
	log.Debugf("Detecting deploy paths on %s...", hostName)

	stdout, err := readStartScript(e, ins.Role(), hostName, ins.GetMainPort())
	if len(stdout) <= 1 || err != nil {
		return ins, err
	}

	switch ins.Role() {
	case meta.ComponentTiDB:
		// parse dirs
		newIns := ins.(meta.TiDBSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "--log-file=") {
				fullLog := strings.Split(line, " ")[4] // 4 whitespaces ahead
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog,
					"--log-file=\""), "/tidb.log\"")
				newIns.LogDir = logDir
				continue
			}
		}
		return newIns, nil
	case meta.ComponentTiKV:
		// parse dirs
		newIns := ins.(meta.TiKVSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "cd \"") {
				newIns.DeployDir = strings.Trim(strings.Split(line, " ")[1], "\"")
				continue
			}
			if strings.Contains(line, "--data-dir") {
				dataDir := strings.Split(line, " ")[5] // 4 whitespaces ahead
				newIns.DataDir = strings.Trim(dataDir, "\"")
				continue
			}
			if strings.Contains(line, "--log-file") {
				fullLog := strings.Split(line, " ")[5] // 4 whitespaces ahead
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog,
					"\""), "/tikv.log\"")
				newIns.LogDir = logDir
				continue
			}
		}
		return newIns, nil
	case meta.ComponentPD:
		// parse dirs
		newIns := ins.(meta.PDSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "--name") {
				nameArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
				name := strings.TrimPrefix(nameArg, "--name=")
				newIns.Name = strings.Trim(name, "\"")
				continue
			}
			if strings.Contains(line, "--data-dir") {
				dataArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
				dataDir := strings.TrimPrefix(dataArg, "--data-dir=")
				newIns.DataDir = strings.Trim(dataDir, "\"")
				continue
			}
			if strings.Contains(line, "--log-file=") {
				fullLog := strings.Split(line, " ")[4] // 4 whitespaces ahead
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog,
					"--log-file=\""), "/pd.log\"")
				newIns.LogDir = logDir
				continue
			}
		}
		return newIns, nil
	case meta.ComponentTiFlash:
		// parse dirs
		newIns := ins.(meta.TiFlashSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "cd \"") {
				newIns.DeployDir = strings.Trim(strings.Split(line, " ")[1], "\"")
				continue
			}
		}
		return newIns, nil
	case meta.ComponentPump:
		// parse dirs
		newIns := ins.(meta.PumpSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "--data-dir") {
				dataArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
				dataDir := strings.TrimPrefix(dataArg, "--data-dir=")
				newIns.DataDir = strings.Trim(dataDir, "\"")
				continue
			}
			if strings.Contains(line, "--log-file=") {
				fullLog := strings.Split(line, " ")[4] // 4 whitespaces ahead
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog,
					"--log-file=\""), "/pump.log\"")
				newIns.LogDir = logDir
				continue
			}
		}
		return newIns, nil
	case meta.ComponentDrainer:
		// parse dirs
		newIns := ins.(meta.DrainerSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "--log-file=") {
				fullLog := strings.Split(line, " ")[4] // 4 whitespaces ahead
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog,
					"--log-file=\""), "/drainer.log\"")
				newIns.LogDir = logDir
				continue
			}
		}
		return newIns, nil
	case meta.ComponentPrometheus:
		// parse dirs
		newIns := ins.(meta.PrometheusSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "exec > >(tee -i -a") {
				fullLog := strings.Split(line, " ")[5]
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog, "\""),
					"/prometheus.log\")")
				newIns.LogDir = logDir
				continue
			}
			if strings.Contains(line, "--storage.tsdb.path=") {
				dataArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
				dataDir := strings.TrimPrefix(dataArg, "--storage.tsdb.path=")
				newIns.DataDir = strings.Trim(dataDir, "\"")
				continue
			}
		}
		return newIns, nil
	case meta.ComponentAlertManager:
		// parse dirs
		newIns := ins.(meta.AlertManagerSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
			if strings.Contains(line, "exec > >(tee -i -a") {
				fullLog := strings.Split(line, " ")[5]
				logDir := strings.TrimSuffix(strings.TrimPrefix(fullLog, "\""),
					"/alertmanager.log\")")
				newIns.LogDir = logDir
				continue
			}
			if strings.Contains(line, "--storage.path=") {
				dataArg := strings.Split(line, " ")[4] // 4 whitespaces ahead
				dataDir := strings.TrimPrefix(dataArg, "--storage.path=")
				newIns.DataDir = strings.Trim(dataDir, "\"")
				continue
			}
		}
		return newIns, nil
	case meta.ComponentGrafana:
		// parse dirs
		newIns := ins.(meta.GrafanaSpec)
		for _, line := range strings.Split(string(stdout), "\n") {
			if strings.HasPrefix(line, "DEPLOY_DIR=") {
				newIns.DeployDir = strings.TrimPrefix(line, "DEPLOY_DIR=")
				continue
			}
		}
		return newIns, nil
	}
	return ins, nil
}

func readStartScript(e *executor.SSHExecutor, component, host string, port int) (string, error) {
	serviceFile := fmt.Sprintf("%s/%s-%d.service",
		systemdUnitPath,
		component,
		port)
	cmd := fmt.Sprintf("cat `grep 'ExecStart' %s | sed 's/ExecStart=//'`", serviceFile)
	stdout, stderr, err := e.Execute(cmd, false)
	if err != nil {
		return string(stdout), err
	}
	if len(stderr) > 0 {
		return string(stdout), errors.Errorf(
			"can not detect dir paths of %s %s:%d, %s",
			component,
			host,
			port,
			stderr,
		)
	}
	return string(stdout), nil
}