package main

import (
	"encoding/json"
	"fmt"
	"github.com/pocketbase/dbx"
	"github.com/pocketbase/pocketbase/models"
	"github.com/pocketbase/pocketbase/tools/cron"
	"io"
	"log"
	"net/http"
	"os"
	"strconv"
	"time"
	"traintimes/trains"

	"github.com/labstack/echo/v5"
	"github.com/pocketbase/pocketbase"
	"github.com/pocketbase/pocketbase/apis"
	"github.com/pocketbase/pocketbase/core"
)

type DummyRecord struct {
	Ts string `json:"ts"`
}

type GetTrainsRec struct {
	From string `db:"from" json:"from"`
	To   string `db:"to" json:"to"`
	Body string `db:"body" json:"body"`
	Ts   int64  `db:"ts" json:"ts"`
	Hash string `db:"hash" json:"hash"`
}

type GetTrainTimesRec struct {
	Hash string `db:"hash" json:"hash"`
	Body string `db:"body" json:"body"`
	Ts   int64  `db:"ts" json:"ts"`
}

const host = "https://huxley2.azurewebsites.net"

var (
	Version string
	Build   string
	tr      = &http.Transport{
		MaxIdleConns:       10,
		IdleConnTimeout:    30 * time.Second,
		DisableCompression: true,
	}
	client     = &http.Client{Transport: tr}
	gmtTimeLoc = time.FixedZone("GMT", 0)
	timeFormat = "Mon, 2 Jan 2006 15:04:05 GMT"
)

func main() {
	log.Printf("GO-TRAINTIMES v%+v build %+v\n\n", Version, Build)
	app := pocketbase.New()

	// serves static files from the provided public dir (if exists)
	app.OnBeforeServe().Add(func(e *core.ServeEvent) error {
		scheduler := cron.New()

		e.Router.GET("/*", apis.StaticDirectoryHandler(os.DirFS("./pb_public"), false))

		e.Router.GET("/gettrains", func(c echo.Context) error {

			apis.ActivityLogger(app)
			return getTrains(c, app)

		})

		e.Router.GET("/getnexttraintimes", func(c echo.Context) error {
			apis.ActivityLogger(app)
			return GetNextTrainTimes(c, app)
		})

		scheduler.MustAdd("cleanup", "*/10 * * * *", func() {
			go CleanupDB(app)
		})

		scheduler.Start()

		return nil
	})

	if err := app.Start(); err != nil {
		log.Fatal(err)
	}
}

func NotImplemented(c echo.Context, from string) error {

	params := c.QueryParams()

	fmt.Printf("NotImplemented from: %s\n", from)
	fmt.Printf("-- %+v\n", params)

	return nil

}

func getTrains(c echo.Context, app *pocketbase.PocketBase) error {
	params := c.QueryParams()

	fmt.Printf("$$:getTrains")
	fmt.Printf("-- %+v\n", params)

	From := c.QueryParamDefault("from", "")
	To := c.QueryParamDefault("to", "")

	ts := time.Now().Unix()

	log.Printf("-- %+v\n", ts)

	log.Printf("-- From: %s\n", From)
	log.Printf("-- To: %s\n", To)

	dummy := DummyRecord{Ts: strconv.FormatInt(ts, 10)}

	if From != "" && To != "" {
		log.Println("-- Got something to search for")

		// check db first..

		recentTrain := GetTrainsRec{}

		hash := fmt.Sprintf("%s%s", From, To)

		dberr := app.Dao().DB().NewQuery("SELECT * FROM trains WHERE hash = {:hash} and ts >= {:ts}").Bind(dbx.Params{
			"ts":   ts - 120,
			"hash": hash,
		}).One(&recentTrain)

		if dberr == nil {
			// handle error
			log.Printf("-- Cache hit train %+v\n", recentTrain.Hash)
			return c.String(200, recentTrain.Body)
		}

		// `/all/${ req.query.from }/to/${ req.query.to }/10?accessToken=215b99fe-b237-4a01-aadc-cf315d6756d8`;
		url := "/all/" + From + "/to/" + To + "/10?accessToken=215b99fe-b237-4a01-aadc-cf315d6756d8"

		log.Printf("-- url: %+v\n", url)

		/*tr := &http.Transport{
			MaxIdleConns:       10,
			IdleConnTimeout:    30 * time.Second,
			DisableCompression: true,
		}*/
		// client := &http.Client{Transport: tr}

		log.Printf("-- full url: %+v\n", host+url)
		resp, err := client.Get(host + url)

		if err != nil {
			// handle error
		}
		defer resp.Body.Close()
		body, err := io.ReadAll(resp.Body)

		if err != nil {
			log.Fatal(err)
		}

		var nTrainRec GetTrainsRec

		nTrainRec.To = To
		nTrainRec.From = From
		nTrainRec.Ts = ts
		nTrainRec.Body = string(body)
		nTrainRec.Hash = hash

		go func() {
			err := saveTrainRec(app, nTrainRec)
			if err != nil {
				log.Println(err)

			}
		}()

		// log.Printf("-- body: %+v\n", string(body))

		// return c.SendString(string(body))
		return c.String(200, string(body))
	}

	return c.JSON(http.StatusAccepted, dummy)
}

func GetNextTrainTimes(c echo.Context, app *pocketbase.PocketBase) error {

	params := c.QueryParams()

	log.Println("$$:GetNextTrainTimes")
	log.Printf("-- %+v\n", params)

	From := c.QueryParamDefault("from", "")
	To := c.QueryParamDefault("to", "")

	ts := time.Now().String()
	tsUnix := time.Now().Unix()
	now := time.Now()
	then := now.Add(-2 * time.Minute)

	log.Printf("-- %+v\n", ts)

	log.Printf("-- From: %+v\n", From)
	log.Printf("-- To: %+v\n", To)

	dummy := DummyRecord{Ts: ts}

	recentTraintimes := GetTrainTimesRec{}

	hash := fmt.Sprintf("%s%s", From, To)

	dberr := app.Dao().DB().NewQuery("SELECT * FROM traintimes WHERE hash = {:hash} and ts >= {:ts}").Bind(dbx.Params{
		"ts":   tsUnix - 120,
		"hash": hash,
	}).One(&recentTraintimes)

	if dberr == nil {
		// handle error
		log.Printf("-- Cache hit traintimes %+v\n", recentTraintimes.Hash)
		return c.String(200, recentTraintimes.Body)
	}

	if From != "" && To != "" {
		log.Println("-- Got something to search for")

		// `/all/${ req.query.from }/to/${ req.query.to }/10?accessToken=215b99fe-b237-4a01-aadc-cf315d6756d8`;
		url := "/next/" + From + "/to/" + To + "?accessToken=215b99fe-b237-4a01-aadc-cf315d6756d8"

		log.Printf("-- url: %+v\n", url)

		log.Printf("-- full url: %+v\n", host+url)

		req, err := http.NewRequest("GET", host+url, nil)

		if err != nil {
			// handle error
		}

		req.Header.Add("If-Modified-Since", then.In(gmtTimeLoc).Format(timeFormat))

		resp, err := client.Do(req)

		defer resp.Body.Close()
		body, err := io.ReadAll(resp.Body)

		if err != nil {
			log.Fatal(err)
		}

		var services trains.AllDepartures
		unerr := json.Unmarshal(body, &services)

		if unerr != nil {

			log.Println("Failed to Unmarshal json")
			panic(unerr)

		}

		departure := reduceNextTrainTimes(services)

		departJson, derr := json.Marshal(departure)

		if derr != nil {

			log.Println("Failed to marshal json")
			panic(derr)

		}

		var nTrainTimesRec GetTrainTimesRec

		nTrainTimesRec.Hash = hash
		nTrainTimesRec.Ts = tsUnix
		nTrainTimesRec.Body = string(departJson)

		go func() {
			err := saveTraintimesRec(app, nTrainTimesRec)
			if err != nil {
				log.Println(err)

			}
		}()

		// log.Println("-- body: %+v\n", string(body))
		// c.Set(fiber.HeaderContentType, fiber.MIMEApplicationJSON)

		// return c.SendString(string(departJson))
		// return c.Send(body)
		return c.String(200, string(departJson))

	}

	return c.JSON(http.StatusAccepted, dummy)
}

func reduceNextTrainTimes(departData trains.AllDepartures) trains.NextTrain {

	// log.Printf("-- obj?: %+v\n", departData)

	depart := departData.Departures[0].Service
	// log.Printf("-- depart: %+v\n", depart)
	var output trains.NextTrain

	if depart.Origin != nil {
		if depart.Sta != "" {
			output.Sta = depart.Sta
		} else {
			output.Sta = depart.Std
		}

		if depart.Eta != "" {
			output.Eta = depart.Eta
		} else {
			output.Eta = depart.Etd
		}

	} else {
		output.Eta = "No Service"
		output.Sta = "No Service"
	}

	// log.Printf("-- output: %+v\n", depart)

	return output
}

func saveTrainRec(app *pocketbase.PocketBase, trainRecord GetTrainsRec) error {

	log.Println("$$:saveTrainRec")

	// foundTrain := GetTrainsRec{}

	collection, err := app.Dao().FindCollectionByNameOrId("trains")
	if err != nil {
		log.Println(err)
		return err
	}

	record, recErr := app.Dao().FindRecordsByExpr("trains", dbx.NewExp("hash = {:hash}", dbx.Params{
		"hash": trainRecord.Hash,
	}))

	if recErr != nil {
		log.Println(recErr)
		return recErr
	}

	if len(record) == 0 {
		log.Printf("-- Insert new train\n")

		record := models.NewRecord(collection)

		record.Set("from", trainRecord.From)
		record.Set("to", trainRecord.To)
		record.Set("body", trainRecord.Body)
		record.Set("ts", trainRecord.Ts)
		record.Set("hash", trainRecord.Hash)

		if err := app.Dao().SaveRecord(record); err != nil {
			log.Println(err)
			return err
		}
	} else {
		log.Printf("-- Update train\n")
		rec := record[0]

		rec.Set("body", trainRecord.Body)
		rec.Set("ts", trainRecord.Ts)

		if err := app.Dao().SaveRecord(rec); err != nil {
			log.Println(err)
			return err
		}

	}

	/*dberr := app.Dao().DB().NewQuery("SELECT * FROM trains WHERE hash = {:hash}").Bind(dbx.Params{
		"hash": trainRecord.Hash,
	}).One(&foundTrain)

	if dberr != nil {
		// handle error
		log.Printf("-- Insert New Record %+v,%+v\n", trainRecord.Hash)
		record := models.NewRecord(collection)

		record.Set("from", trainRecord.From)
		record.Set("to", trainRecord.To)
		record.Set("body", trainRecord.Body)
		record.Set("ts", trainRecord.Ts)
		record.Set("hash", trainRecord.Hash)

		if err := app.Dao().SaveRecord(record); err != nil {
			log.Println(err)
			return err
		}

	} else {

		foundTrain.Ts = trainRecord.Ts
		foundTrain.Body = trainRecord.Body

		record := models.NewRecord(foundTrain)

		if err := app.Dao().SaveRecord(record); err != nil {
			log.Println(err)
			return err
		}

	}*/

	return nil
}

func saveTraintimesRec(app *pocketbase.PocketBase, traintimesRecord GetTrainTimesRec) error {

	log.Println("$$:saveTraintimesRec")

	// foundTrain := GetTrainsRec{}

	collection, err := app.Dao().FindCollectionByNameOrId("traintimes")
	if err != nil {
		log.Println(err)
		return err
	}

	record, recErr := app.Dao().FindRecordsByExpr("traintimes", dbx.NewExp("hash = {:hash}", dbx.Params{
		"hash": traintimesRecord.Hash,
	}))

	if recErr != nil {
		log.Println(recErr)
		return recErr
	}

	if len(record) == 0 {
		log.Printf("-- Insert new traintimes\n")

		record := models.NewRecord(collection)

		record.Set("body", traintimesRecord.Body)
		record.Set("ts", traintimesRecord.Ts)
		record.Set("hash", traintimesRecord.Hash)

		if err := app.Dao().SaveRecord(record); err != nil {
			log.Println(err)
			return err
		}
	} else {
		log.Printf("-- Update traintimes\n")
		rec := record[0]

		rec.Set("body", traintimesRecord.Body)
		rec.Set("ts", traintimesRecord.Ts)

		if err := app.Dao().SaveRecord(rec); err != nil {
			log.Println(err)
			return err
		}

	}

	return nil
}

func CleanupDB(app *pocketbase.PocketBase) {

	ts := time.Now().Unix() - 600

	log.Println("$$:CleanupDB", ts)

	/*raw := "Delete from trains where ts <=" + strconv.FormatInt(ts, 10)

	if _, err := app.Dao().DB().NewQuery(raw).Execute(); err != nil {
		log.Fatalln(err)

	}*/

}