package main

import (
	"encoding/csv"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"net/url"
	"os"
	"os/user"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"text/tabwriter"

	"github.com/influxdb/influxdb/client"
	"github.com/peterh/liner"
)

// These variables are populated via the Go linker.
var (
	version string = "0.9"
)

const (
	default_host   = "localhost"
	default_port   = 8086
	default_format = "column"
)

type CommandLine struct {
	Client          *client.Client
	Line            *liner.State
	Host            string
	Port            int
	Username        string
	Password        string
	Database        string
	Ssl             bool
	RetentionPolicy string
	Version         string
	Pretty          bool   // controls pretty print for json
	Format          string // controls the output format.  Valid values are json, csv, or column
	Execute         string
	ShowVersion     bool
}

func main() {
	c := CommandLine{}

	fs := flag.NewFlagSet("InfluxDB shell version "+version, flag.ExitOnError)
	fs.StringVar(&c.Host, "host", default_host, "Influxdb host to connect to.")
	fs.IntVar(&c.Port, "port", default_port, "Influxdb port to connect to.")
	fs.StringVar(&c.Username, "username", c.Username, "Username to connect to the server.")
	fs.StringVar(&c.Password, "password", c.Password, `Password to connect to the server.  Leaving blank will prompt for password (--password="").`)
	fs.StringVar(&c.Database, "database", c.Database, "Database to connect to the server.")
	fs.BoolVar(&c.Ssl, "ssl", false, "Use https for connecting to cluster.")
	fs.StringVar(&c.Format, "format", default_format, "Format specifies the format of the server responses:  json, csv, or column.")
	fs.BoolVar(&c.Pretty, "pretty", false, "Turns on pretty print for the json format.")
	fs.StringVar(&c.Execute, "execute", c.Execute, "Execute command and quit.")
	fs.BoolVar(&c.ShowVersion, "version", false, "Displays the InfluxDB version.")

	// Define our own custom usage to print
	fs.Usage = func() {
		fmt.Println(`Usage of influx:
  -version
       Display the version and exit.
  -host 'host name'
       Host to connect to.
  -port 'port #'
       Port to connect to.
  -database 'database name'
       Database to connect to the server.
  -password 'password'
      Password to connect to the server.  Leaving blank will prompt for password (--password '').
  -username 'username'
       Username to connect to the server.
  -ssl
        Use https for requests.
  -execute 'command'
       Execute command and quit.
  -format 'json|csv|column'
       Format specifies the format of the server responses:  json, csv, or column.
  -pretty
       Turns on pretty print for the json format.

Examples:

    # Use influx in a non-interactive mode to query the database "metrics" and pretty print json:
    $ influx -database 'metrics' -execute 'select * from cpu' -format 'json' -pretty

	# Connect to a specific database on startup and set database context:
    $ influx -database 'metrics' -host 'localhost' -port '8086'
`)
	}
	fs.Parse(os.Args[1:])

	if c.ShowVersion {
		showVersion()
		os.Exit(0)
	}

	var promptForPassword bool
	// determine if they set the password flag but provided no value
	for _, v := range os.Args {
		v = strings.ToLower(v)
		if (strings.HasPrefix(v, "-password") || strings.HasPrefix(v, "--password")) && c.Password == "" {
			promptForPassword = true
			break
		}
	}

	c.Line = liner.NewLiner()
	defer c.Line.Close()

	if promptForPassword {
		p, e := c.Line.PasswordPrompt("password: ")
		if e != nil {
			fmt.Println("Unable to parse password.")
		} else {
			c.Password = p
		}
	}

	c.connect("")

	if c.Execute != "" {
		if err := c.ExecuteQuery(c.Execute); err != nil {
			c.Line.Close()
			os.Exit(1)
		} else {
			c.Line.Close()
			os.Exit(0)
		}
	}

	showVersion()

	var historyFile string
	usr, err := user.Current()
	// Only load history if we can get the user
	if err == nil {
		historyFile = filepath.Join(usr.HomeDir, ".influx_history")

		if f, err := os.Open(historyFile); err == nil {
			c.Line.ReadHistory(f)
			f.Close()
		}
	}

	for {
		l, e := c.Line.Prompt("> ")
		if e != nil {
			break
		}
		if c.ParseCommand(l) {
			// write out the history
			if len(historyFile) > 0 {
				c.Line.AppendHistory(l)
				if f, err := os.Create(historyFile); err == nil {
					c.Line.WriteHistory(f)
					f.Close()
				}
			}
		} else {
			break // exit main loop
		}
	}
}

func showVersion() {
	fmt.Println("InfluxDB shell " + version)
}

func (c *CommandLine) ParseCommand(cmd string) bool {
	lcmd := strings.TrimSpace(strings.ToLower(cmd))
	switch {
	case strings.HasPrefix(lcmd, "exit"):
		// signal the program to exit
		return false
	case strings.HasPrefix(lcmd, "gopher"):
		c.gopher()
	case strings.HasPrefix(lcmd, "connect"):
		c.connect(cmd)
	case strings.HasPrefix(lcmd, "auth"):
		c.SetAuth(cmd)
	case strings.HasPrefix(lcmd, "help"):
		c.help()
	case strings.HasPrefix(lcmd, "format"):
		c.SetFormat(cmd)
	case strings.HasPrefix(lcmd, "settings"):
		c.Settings()
	case strings.HasPrefix(lcmd, "pretty"):
		c.Pretty = !c.Pretty
		if c.Pretty {
			fmt.Println("Pretty print enabled")
		} else {
			fmt.Println("Pretty print disabled")
		}
	case strings.HasPrefix(lcmd, "use"):
		c.use(cmd)
	case strings.HasPrefix(lcmd, "insert"):
		c.Insert(cmd)
	case lcmd == "":
		break
	default:
		c.ExecuteQuery(cmd)
	}
	return true
}

func (c *CommandLine) connect(cmd string) {
	var cl *client.Client

	if cmd != "" {
		// Remove the "connect" keyword if it exists
		cmd = strings.TrimSpace(strings.Replace(cmd, "connect", "", -1))
		if cmd == "" {
			return
		}
		if strings.Contains(cmd, ":") {
			h := strings.Split(cmd, ":")
			i, e := strconv.Atoi(h[1])
			if e != nil {
				fmt.Printf("Connect error: Invalid port number %q: %s\n", cmd, e)
				return
			}
			c.Port = i
			if h[0] == "" {
				c.Host = default_host
			} else {
				c.Host = h[0]
			}
		} else {
			c.Host = cmd
			// If they didn't specify a port, always use the default port
			c.Port = default_port
		}
	}

	u := url.URL{
		Scheme: "http",
	}
	if c.Ssl {
		u.Scheme = "https"
	}
	if c.Port > 0 {
		u.Host = fmt.Sprintf("%s:%d", c.Host, c.Port)
	} else {
		u.Host = c.Host
	}
	cl, err := client.NewClient(
		client.Config{
			URL:       u,
			Username:  c.Username,
			Password:  c.Password,
			UserAgent: "InfluxDBShell/" + version,
		})
	if err != nil {
		fmt.Printf("Could not create client %s", err)
		return
	}
	c.Client = cl
	if _, v, e := c.Client.Ping(); e != nil {
		fmt.Printf("Failed to connect to %s\n", c.Client.Addr())
	} else {
		c.Version = v
		if c.Execute == "" {
			fmt.Printf("Connected to %s version %s\n", c.Client.Addr(), c.Version)
		}
	}
}

func (c *CommandLine) SetAuth(cmd string) {
	// If they pass in the entire command, we should parse it
	// auth <username> <password>
	args := strings.Fields(cmd)
	if len(args) == 3 {
		args = args[1:]
	} else {
		args = []string{}
	}

	if len(args) == 2 {
		c.Username = args[0]
		c.Password = args[1]
	} else {
		u, e := c.Line.Prompt("username: ")
		if e != nil {
			fmt.Printf("Unable to process input: %s", e)
			return
		}
		c.Username = strings.TrimSpace(u)
		p, e := c.Line.PasswordPrompt("password: ")
		if e != nil {
			fmt.Printf("Unable to process input: %s", e)
			return
		}
		c.Password = p
	}

	// Update the client as well
	c.Client.SetAuth(c.Username, c.Password)
}

func (c *CommandLine) use(cmd string) {
	args := strings.Split(strings.TrimSuffix(strings.TrimSpace(cmd), ";"), " ")
	if len(args) != 2 {
		fmt.Printf("Could not parse database name from %q.\n", cmd)
		return
	}
	d := args[1]
	c.Database = d
	fmt.Printf("Using database %s\n", d)
}

func (c *CommandLine) SetFormat(cmd string) {
	// Remove the "format" keyword if it exists
	cmd = strings.TrimSpace(strings.Replace(cmd, "format", "", -1))
	// normalize cmd
	cmd = strings.ToLower(cmd)

	switch cmd {
	case "json", "csv", "column":
		c.Format = cmd
	default:
		fmt.Printf("Unknown format %q. Please use json, csv, or column.\n", cmd)
	}
}

// isWhitespace returns true if the rune is a space, tab, or newline.
func isWhitespace(ch rune) bool { return ch == ' ' || ch == '\t' || ch == '\n' }

// isLetter returns true if the rune is a letter.
func isLetter(ch rune) bool { return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') }

// isDigit returns true if the rune is a digit.
func isDigit(ch rune) bool { return (ch >= '0' && ch <= '9') }

// isIdentFirstChar returns true if the rune can be used as the first char in an unquoted identifer.
func isIdentFirstChar(ch rune) bool { return isLetter(ch) || ch == '_' }

// isIdentChar returns true if the rune can be used in an unquoted identifier.
func isNotIdentChar(ch rune) bool { return !(isLetter(ch) || isDigit(ch) || ch == '_') }

func parseUnquotedIdentifier(stmt string) (string, string) {
	if fields := strings.FieldsFunc(stmt, isNotIdentChar); len(fields) > 0 {
		return fields[0], strings.TrimPrefix(stmt, fields[0])
	}
	return "", stmt
}

func parseDoubleQuotedIdentifier(stmt string) (string, string) {
	escapeNext := false
	fields := strings.FieldsFunc(stmt, func(ch rune) bool {
		if ch == '\\' {
			escapeNext = true
		} else if ch == '"' {
			if !escapeNext {
				return true
			}
			escapeNext = false
		}
		return false
	})
	if len(fields) > 0 {
		return fields[0], strings.TrimPrefix(stmt, "\""+fields[0]+"\"")
	}
	return "", stmt
}

func parseNextIdentifier(stmt string) (ident, remainder string) {
	if len(stmt) > 0 {
		switch {
		case isWhitespace(rune(stmt[0])):
			return parseNextIdentifier(stmt[1:])
		case isIdentFirstChar(rune(stmt[0])):
			return parseUnquotedIdentifier(stmt)
		case stmt[0] == '"':
			return parseDoubleQuotedIdentifier(stmt)
		}
	}
	return "", stmt
}

func (c *CommandLine) parseInto(stmt string) string {
	ident, stmt := parseNextIdentifier(stmt)
	if strings.HasPrefix(stmt, ".") {
		c.Database = ident
		fmt.Printf("Using database %s\n", c.Database)
		ident, stmt = parseNextIdentifier(stmt[1:])
	}
	if strings.HasPrefix(stmt, " ") {
		c.RetentionPolicy = ident
		fmt.Printf("Using retention policy %s\n", c.RetentionPolicy)
		return stmt[1:]
	}
	return stmt
}

func (c *CommandLine) Insert(stmt string) error {
	i, point := parseNextIdentifier(stmt)
	if !strings.EqualFold(i, "insert") {
		fmt.Printf("ERR: found %s, expected INSERT\n", i)
		return nil
	}
	if i, r := parseNextIdentifier(point); strings.EqualFold(i, "into") {
		point = c.parseInto(r)
	}
	_, err := c.Client.Write(client.BatchPoints{
		Points: []client.Point{
			client.Point{Raw: point},
		},
		Database:         c.Database,
		RetentionPolicy:  c.RetentionPolicy,
		Precision:        "n",
		WriteConsistency: client.ConsistencyAny,
	})
	if err != nil {
		fmt.Printf("ERR: %s\n", err)
		if c.Database == "" {
			fmt.Println("Note: error may be due to not setting a database or retention policy.")
			fmt.Println(`Please set a database with the command "use <database>" or`)
			fmt.Println("INSERT INTO <database>.<retention-policy> <point>")
		}
		return err
	}
	return nil
}

func (c *CommandLine) ExecuteQuery(query string) error {
	response, err := c.Client.Query(client.Query{Command: query, Database: c.Database})
	if err != nil {
		fmt.Printf("ERR: %s\n", err)
		return err
	}
	c.FormatResponse(response, os.Stdout)
	if err := response.Error(); err != nil {
		fmt.Printf("ERR: %s\n", response.Error())
		if c.Database == "" {
			fmt.Println("Warning: It is possible this error is due to not setting a database.")
			fmt.Println(`Please set a database with the command "use <database>".`)
		}
		return err
	}
	return nil
}

func (c *CommandLine) FormatResponse(response *client.Response, w io.Writer) {
	switch c.Format {
	case "json":
		c.writeJSON(response, w)
	case "csv":
		c.writeCSV(response, w)
	case "column":
		c.writeColumns(response, w)
	default:
		fmt.Fprintf(w, "Unknown output format %q.\n", c.Format)
	}
}

func (c *CommandLine) writeJSON(response *client.Response, w io.Writer) {
	var data []byte
	var err error
	if c.Pretty {
		data, err = json.MarshalIndent(response, "", "    ")
	} else {
		data, err = json.Marshal(response)
	}
	if err != nil {
		fmt.Fprintf(w, "Unable to parse json: %s\n", err)
		return
	}
	fmt.Fprintln(w, string(data))
}

func (c *CommandLine) writeCSV(response *client.Response, w io.Writer) {
	csvw := csv.NewWriter(w)
	for _, result := range response.Results {
		// Create a tabbed writer for each result as they won't always line up
		rows := c.formatResults(result, "\t")
		for _, r := range rows {
			csvw.Write(strings.Split(r, "\t"))
		}
		csvw.Flush()
	}
}

func (c *CommandLine) writeColumns(response *client.Response, w io.Writer) {
	for _, result := range response.Results {
		// Create a tabbed writer for each result a they won't always line up
		w := new(tabwriter.Writer)
		w.Init(os.Stdout, 0, 8, 1, '\t', 0)
		csv := c.formatResults(result, "\t")
		for _, r := range csv {
			fmt.Fprintln(w, r)
		}
		w.Flush()
	}
}

// formatResults will behave differently if you are formatting for columns or csv
func (c *CommandLine) formatResults(result client.Result, separator string) []string {
	rows := []string{}
	// Create a tabbed writer for each result a they won't always line up
	for i, row := range result.Series {
		// gather tags
		tags := []string{}
		for k, v := range row.Tags {
			tags = append(tags, fmt.Sprintf("%s=%s", k, v))
			sort.Strings(tags)
		}

		columnNames := []string{}

		// Only put name/tags in a column if format is csv
		if c.Format == "csv" {
			if len(tags) > 0 {
				columnNames = append([]string{"tags"}, columnNames...)
			}

			if row.Name != "" {
				columnNames = append([]string{"name"}, columnNames...)
			}
		}

		for _, column := range row.Columns {
			columnNames = append(columnNames, column)
		}

		// Output a line separator if we have more than one set or results and format is column
		if i > 0 && c.Format == "column" {
			rows = append(rows, "")
		}

		// If we are column format, we break out the name/tag to seperate lines
		if c.Format == "column" {
			if row.Name != "" {
				n := fmt.Sprintf("name: %s", row.Name)
				rows = append(rows, n)
				if len(tags) == 0 {
					l := strings.Repeat("-", len(n))
					rows = append(rows, l)
				}
			}
			if len(tags) > 0 {
				t := fmt.Sprintf("tags: %s", (strings.Join(tags, ", ")))
				rows = append(rows, t)
			}
		}

		rows = append(rows, strings.Join(columnNames, separator))

		// if format is column, break tags to their own line/format
		if c.Format == "column" && len(tags) > 0 {
			lines := []string{}
			for _, columnName := range columnNames {
				lines = append(lines, strings.Repeat("-", len(columnName)))
			}
			rows = append(rows, strings.Join(lines, separator))
		}

		for _, v := range row.Values {
			var values []string
			if c.Format == "csv" {
				if row.Name != "" {
					values = append(values, row.Name)
				}
				if len(tags) > 0 {
					values = append(values, strings.Join(tags, ","))
				}
			}

			for _, vv := range v {
				values = append(values, interfaceToString(vv))
			}
			rows = append(rows, strings.Join(values, separator))
		}
		// Outout a line separator if in column format
		if c.Format == "column" {
			rows = append(rows, "")
		}
	}
	return rows
}

func interfaceToString(v interface{}) string {
	switch t := v.(type) {
	case nil:
		return ""
	case bool:
		return fmt.Sprintf("%v", v)
	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, uintptr:
		return fmt.Sprintf("%d", t)
	case float32, float64:
		return fmt.Sprintf("%v", t)
	default:
		return fmt.Sprintf("%v", t)
	}
}

func (c *CommandLine) Settings() {
	w := new(tabwriter.Writer)
	w.Init(os.Stdout, 0, 8, 1, '\t', 0)
	if c.Port > 0 {
		fmt.Fprintf(w, "Host\t%s:%d\n", c.Host, c.Port)
	} else {
		fmt.Fprintf(w, "Host\t%s\n", c.Host)
	}
	fmt.Fprintf(w, "Username\t%s\n", c.Username)
	fmt.Fprintf(w, "Database\t%s\n", c.Database)
	fmt.Fprintf(w, "Pretty\t%v\n", c.Pretty)
	fmt.Fprintf(w, "Format\t%s\n", c.Format)
	fmt.Fprintln(w)
	w.Flush()
}

func (c *CommandLine) help() {
	fmt.Println(`Usage:
        connect <host:port>   connect to another node
        auth                  prompt for username and password
        pretty                toggle pretty print
        use <db_name>         set current databases
        format <format>       set the output format: json, csv, or column
        settings              output the current settings for the shell
        exit                  quit the influx shell

        show databases        show database names
        show series           show series information
        show measurements     show measurement information
        show tag keys         show tag key information
        show tag values       show tag value information

        a full list of influxql commands can be found at:
        https://influxdb.com/docs/v0.9/query_language/spec.html
`)
}

func (c *CommandLine) gopher() {
	fmt.Println(`
                                          .-::-::://:-::-    .:/++/'
                                     '://:-''/oo+//++o+/.://o-    ./+:
                                  .:-.    '++-         .o/ '+yydhy'  o-
                               .:/.      .h:         :osoys  .smMN-  :/
                            -/:.'        s-         /MMMymh.   '/y/  s'
                         -+s:''''        d          -mMMms//     '-/o:
                       -/++/++/////:.    o:          '... s-        :s.
                     :+-+s-'       ':/'  's-             /+          'o:
                   '+-'o:        /ydhsh.  '//.        '-o-             o-
                  .y. o:        .MMMdm+y    ':+++:::/+:.'               s:
                .-h/  y-        'sdmds'h -+ydds:::-.'                   'h.
             .//-.d'  o:          '.' 'dsNMMMNh:.:++'                    :y
            +y.  'd   's.            .s:mddds:     ++                     o/
           'N-  odd    'o/.       './o-s-'   .---+++'                      o-
           'N'  yNd      .://:/:::::. -s   -+/s/./s'                       'o/'
            so'  .h         ''''       ////s: '+. .s                         +y'
             os/-.y'                       's' 'y::+                          +d'
               '.:o/                        -+:-:.'                            so.---.'
                   o'                                                          'd-.''/s'
                   .s'                                                          :y.''.y
                    -s                                                           mo:::'
                     ::                                                          yh
                      //                                      ''''               /M'
                       o+                                    .s///:/.            'N:
                        :+                                   /:    -s'            ho
                         's-                               -/s/:+/.+h'            +h
                           ys'                            ':'    '-.              -d
                            oh                                                    .h
                             /o                                                   .s
                              s.                                                  .h
                              -y                                                  .d
                               m/                                                 -h
                               +d                                                 /o
                               'N-                                                y:
                                h:                                                m.
                                s-                                               -d
                                o-                                               s+
                                +-                                              'm'
                                s/                                              oo--.
                                y-                                             /s  ':+'
                                s'                                           'od--' .d:
                                -+                                         ':o: ':+-/+
                                 y-                                      .:+-      '
                                //o-                                 '.:+/.
                                .-:+/'                           ''-/+/.
                                    ./:'                    ''.:o+/-'
                                      .+o:/:/+-'      ''.-+ooo/-'
                                         o:   -h///++////-.
                                        /:   .o/
                                       //+  'y
                                       ./sooy.

`)
}