/*
Copyright 2016 The Fission Authors.

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,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/exec"
	"strings"
	"text/tabwriter"
	"time"

	"github.com/satori/go.uuid"
	"github.com/urfave/cli"

	"github.com/fission/fission"
	"github.com/fission/fission/fission/logdb"
)

func fnFetchCode(filePath string) []byte {
	var code []byte
	var err error

	if strings.HasPrefix(filePath, "http://") || strings.HasPrefix(filePath, "https://") {
		var resp *http.Response
		resp, err = http.Get(filePath)
		if err != nil {
			checkErr(err, fmt.Sprintf("download function"))
		}

		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			err = fmt.Errorf("%v - HTTP response returned non 200 status", resp.StatusCode)
			checkErr(err, fmt.Sprintf("download function"))
		}

		code, err = ioutil.ReadAll(resp.Body)
		if err != nil {
			checkErr(err, fmt.Sprintf("download function body %v", filePath))
		}
	} else {
		code, err = ioutil.ReadFile(filePath)
		checkErr(err, fmt.Sprintf("read %v", filePath))
	}
	return code
}

func fnCreate(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need --name argument.")
	}

	envName := c.String("env")
	if len(envName) == 0 {
		fatal("Need --env argument.")
	}

	fileName := c.String("code")
	if len(fileName) == 0 {
		fileName = c.String("package")
		if len(fileName) == 0 {
			fatal("Need --code or --package argument.")
		}
	}

	code := fnFetchCode(fileName)

	function := &fission.Function{
		Metadata:    fission.Metadata{Name: fnName},
		Environment: fission.Metadata{Name: envName},
		Code:        string(code),
	}

	_, err := client.FunctionCreate(function)
	checkErr(err, "create function")

	fmt.Printf("function '%v' created\n", fnName)

	// Allow the user to specify an HTTP trigger while creating a function.
	triggerUrl := c.String("url")
	if len(triggerUrl) == 0 {
		return nil
	}
	method := c.String("method")
	if len(method) == 0 {
		method = "GET"
	}
	triggerName := uuid.NewV4().String()
	ht := &fission.HTTPTrigger{
		Metadata: fission.Metadata{
			Name: triggerName,
		},
		UrlPattern: triggerUrl,
		Method:     getMethod(method),
		Function: fission.Metadata{
			Name: fnName,
		},
	}
	_, err = client.HTTPTriggerCreate(ht)
	checkErr(err, "create HTTP trigger")
	fmt.Printf("route created: %v %v -> %v\n", method, triggerUrl, fnName)

	return err
}

func fnGet(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}
	fnUid := c.String("uid")
	m := &fission.Metadata{Name: fnName, Uid: fnUid}

	code, err := client.FunctionGetRaw(m)
	checkErr(err, "get function")

	fmt.Println(string(code))
	return err
}

func fnGetMeta(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}

	fnUid := c.String("uid")
	m := &fission.Metadata{Name: fnName, Uid: fnUid}

	f, err := client.FunctionGet(m)
	checkErr(err, "get function")

	w := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)
	fmt.Fprintf(w, "%v\t%v\t%v\n", "NAME", "UID", "ENV")
	fmt.Fprintf(w, "%v\t%v\t%v\n",
		f.Metadata.Name, f.Metadata.Uid, f.Environment.Name)
	w.Flush()
	return err
}

func fnUpdate(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}

	function, err := client.FunctionGet(&fission.Metadata{Name: fnName})
	checkErr(err, fmt.Sprintf("read function '%v'", fnName))

	envName := c.String("env")
	if len(envName) > 0 {
		function.Environment.Name = envName
	}

	fileName := c.String("code")
	if len(fileName) == 0 {
		fileName = c.String("package")
	}

	if len(envName) == 0 && len(fileName) == 0 {
		fatal("Need --env or --code or --package argument.")
	}

	if len(fileName) > 0 {
		code := fnFetchCode(fileName)
		function.Code = string(code)
	}

	_, err = client.FunctionUpdate(function)
	checkErr(err, "update function")

	fmt.Printf("function '%v' updated\n", fnName)
	return err
}

func fnDelete(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}

	fnUid := c.String("uid")
	m := &fission.Metadata{Name: fnName, Uid: fnUid}

	err := client.FunctionDelete(m)
	checkErr(err, fmt.Sprintf("delete function '%v'", fnName))

	fmt.Printf("function '%v' deleted\n", fnName)
	return err
}

func fnList(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fns, err := client.FunctionList()
	checkErr(err, "list functions")

	w := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)

	fmt.Fprintf(w, "%v\t%v\t%v\n", "NAME", "UID", "ENV")
	for _, f := range fns {
		fmt.Fprintf(w, "%v\t%v\t%v\n",
			f.Metadata.Name, f.Metadata.Uid, f.Environment.Name)
	}
	w.Flush()

	return err
}

func fnEdit(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}
	fnUid := c.String("uid")

	// get function meta
	function, err := client.FunctionGet(&fission.Metadata{Name: fnName, Uid: fnUid})
	checkErr(err, fmt.Sprintf("read function '%v'", fnName))

	// write to tmp file
	tmpFile, err := ioutil.TempFile("", fnName)
	checkErr(err, "create temp file")
	defer os.Remove(tmpFile.Name())

	_, err = tmpFile.Write([]byte(function.Code))
	checkErr(err, "write temp file")
	tmpFile.Close()

	// invoke $EDITOR on tmp file and wait for it
	editor := os.Getenv("EDITOR")
	if len(editor) == 0 {
		editor = "vi"
	}
	cmd := exec.Command("/bin/sh", "-c", fmt.Sprintf("%v %v", editor, tmpFile.Name()))
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	err = cmd.Start()
	checkErr(err, "start editor")

	err = cmd.Wait()
	checkErr(err, "wait for editor")

	// read new code out of the file
	contents, err := ioutil.ReadFile(tmpFile.Name())
	checkErr(err, "read temp file")

	function.Code = string(contents)

	// upload the updated function
	newfn, err := client.FunctionUpdate(function)
	checkErr(err, "upload edited function")

	fmt.Printf("function %v updated, new uuid: %v\n", newfn.Name, newfn.Uid)
	return nil
}

func fnLogs(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}

	dbType := c.String("dbtype")
	if len(dbType) == 0 {
		dbType = logdb.INFLUXDB
	}

	fnPod := c.String("pod")
	m := &fission.Metadata{Name: fnName}

	f, err := client.FunctionGet(m)
	checkErr(err, "get function")

	// client first send db query to controller, then controller will
	// establishe a proxy server that bridges the client and the database.
	logDB, err := logdb.GetLogDB(dbType, c.GlobalString("server"))
	if err != nil {
		fatal("failed to connect log database")
	}

	requestChan := make(chan struct{})
	responseChan := make(chan struct{})
	ctx := context.Background()

	go func(ctx context.Context, requestChan, responseChan chan struct{}) {
		t := time.Unix(0, 0*int64(time.Millisecond))
		for {
			select {
			case <-requestChan:
				logFilter := logdb.LogFilter{
					Pod:      fnPod,
					Function: f.Metadata.Name,
					FuncUid:  f.Metadata.Uid,
					Since:    t,
				}
				logEntries, err := logDB.GetLogs(logFilter)
				if err != nil {
					fatal("failed to query logs")
				}
				for _, logEntry := range logEntries {
					if c.Bool("d") {
						fmt.Printf("Timestamp: %s\nNamespace: %s\nFunction Name: %s\nFunction ID: %s\nPod: %s\nContainer: %s\nStream: %s\nLog: %s\n---\n",
							logEntry.Timestamp, logEntry.Namespace, logEntry.FuncName, logEntry.FuncUid, logEntry.Pod, logEntry.Container, logEntry.Stream, logEntry.Message)
					} else {
						fmt.Printf("[%s] %s\n", logEntry.Timestamp, logEntry.Message)
					}
					t = logEntry.Timestamp
				}
				responseChan <- struct{}{}
			case <-ctx.Done():
				return
			}
		}
	}(ctx, requestChan, responseChan)

	for {
		requestChan <- struct{}{}
		<-responseChan
		if !c.Bool("f") {
			ctx.Done()
			return nil
		}
		time.Sleep(1 * time.Second)
	}
}

func fnPods(c *cli.Context) error {
	client := getClient(c.GlobalString("server"))

	fnName := c.String("name")
	if len(fnName) == 0 {
		fatal("Need name of function, use --name")
	}

	dbType := c.String("dbtype")
	if len(dbType) == 0 {
		dbType = logdb.INFLUXDB
	}

	m := &fission.Metadata{Name: fnName}

	f, err := client.FunctionGet(m)
	checkErr(err, "get function")

	// client first sends db query to the controller, then the controller
	// will establish a proxy server that bridges the client and the database.
	logDB, err := logdb.GetLogDB(dbType, c.GlobalString("server"))
	if err != nil {
		fatal("failed to connect log database")
	}

	logFilter := logdb.LogFilter{
		Function: f.Metadata.Name,
		FuncUid:  f.Metadata.Uid,
	}
	pods, err := logDB.GetPods(logFilter)
	if err != nil {
		fatal("failed to get pods of function")
		return err
	}
	fmt.Printf("NAME\t\n")
	for _, pod := range pods {
		fmt.Println(pod)
	}

	return err
}