package main

import (
	"context"
	"flag"
	"fmt"
	"go/slack-bot/pkg/check"
	"go/slack-bot/pkg/notify"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"

	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/gohcl"
	"github.com/hashicorp/hcl/v2/hclsyntax"
)

//SlackConf bot global configuration
type SlackConf struct {
	BotID         string              `hcl:"bot_id"`
	DestChannelID string              `hcl:"dest_channel_id"`
	WebhookID     string              `hcl:"webhook_id"`
	DryRun        *bool               `hcl:"dry_run"`
	Df            []check.DfParameter `hcl:"df,block"`
}

func main() {
	var configFile string
	flag.StringVar(&configFile, "config", "config.hcl", "hcl application configuration file")
	flag.Parse()

	conf := ParseConfiguration(configFile)
	slackNotifier := notify.NewSlackNotifier(conf.BotID, conf.DestChannelID, conf.WebhookID)

	dfChecker := check.NewDfChecker()

	msg := dfChecker.Check(func(stdout string) []notify.Message {
		var messages []notify.Message
		parsedDf := dfChecker.Parse(stdout)
		casted := parsedDf.(check.DfStdout)
		for _, dfCheck := range conf.Df {
			messages = append(messages, dfChecker.FileSystemUsedCheck(casted, dfCheck))
		}
		return messages
	})

	dryRunCtx := context.WithValue(context.Background(), notify.DryRunContextKey, conf.DryRun)
	slackNotifier.Notify(dryRunCtx, msg...)
}

//ParseConfiguration take filename path and parse it to Config.SlackConf
func ParseConfiguration(filename string) *SlackConf {
	dir, err := os.Getwd()
	if err != nil {
		log.Fatalf("Fail to determine current directory to load default ./config.hcl file, %+v\n", err)
	}
	log.Printf("current dir is %s", dir)

	if filename == "config.hcl" {
		filename = fmt.Sprintf("%s%c%s", dir, os.PathSeparator, filename)
	}
	relativeFilename, err := filepath.Rel(dir, filename)
	if err != nil {
		log.Fatalf("Fail to determine configuration relative directory for file %s, %+v", filename, err)
	}

	src, err := ioutil.ReadFile(relativeFilename)
	if err != nil {
		log.Fatalf("Missing required parameter filename got : %s, %+v", relativeFilename, err)
	}
	file, diags := hclsyntax.ParseConfig(src, relativeFilename, hcl.Pos{Line: 1, Column: 1})
	if diags.HasErrors() {
		log.Fatalf("parse config error, %s", diags.Error())
	}

	config := &SlackConf{}

	diags = gohcl.DecodeBody(file.Body, nil, config)
	if diags.HasErrors() {
		log.Fatalf("error config decode, %s", diags.Error())
	}

	if config.BotID == "" || config.DestChannelID == "" || config.WebhookID == "" {
		log.Fatal("Missing required parameter : bot_id, dest_channel_id or webhook_id")
	}
	return config
}