rest: create plugin

RestPlugin allows users to dynamically create transports and integrate services
from outside of catbase.

New commands:
* wire `regex` to URL `field`
* list wires
* rm wire ID
This commit is contained in:
Chris Sexton 2021-05-19 11:46:23 -04:00 committed by Chris Sexton
parent 2045fc4591
commit 1e5a82d281
2 changed files with 286 additions and 0 deletions

View File

@ -15,6 +15,7 @@ import (
"github.com/velour/catbase/plugins/giphy"
"github.com/velour/catbase/plugins/gpt2"
"github.com/velour/catbase/plugins/last"
"github.com/velour/catbase/plugins/rest"
"github.com/velour/catbase/plugins/achievements"
"github.com/velour/catbase/plugins/aoc"
@ -158,6 +159,7 @@ func main() {
b.AddPlugin(achievements.New(b))
b.AddPlugin(sms.New(b))
b.AddPlugin(countdown.New(b))
b.AddPlugin(rest.New(b))
// catches anything left, will always return true
b.AddPlugin(fact.New(b))

284
plugins/rest/rest.go Normal file
View File

@ -0,0 +1,284 @@
package rest
import (
"bytes"
"database/sql"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"regexp"
"strconv"
"strings"
"text/template"
"github.com/jmoiron/sqlx"
"github.com/velour/catbase/bot"
)
type RestPlugin struct {
b bot.Bot
db *sqlx.DB
handlers bot.HandlerTable
}
func New(b bot.Bot) *RestPlugin {
p := &RestPlugin{
b: b,
db: b.DB(),
handlers: bot.HandlerTable{},
}
p.setupDB()
p.register()
return p
}
func (p *RestPlugin) setupDB() {
tx := p.db.MustBegin()
tx.MustExec(`
create table if not exists wires (
id integer primary key autoincrement,
url text not null,
parse_regex text not null,
return_field text not null
)`)
if err := tx.Commit(); err != nil {
panic(err)
}
}
func (p *RestPlugin) register() {
p.handlers = bot.HandlerTable{
bot.HandlerSpec{Kind: bot.Message, IsCmd: true,
Regex: regexp.MustCompile("(?i)^list wires$"),
HelpText: "Lists all REST functions",
Handler: p.listWires},
bot.HandlerSpec{Kind: bot.Message, IsCmd: true,
Regex: regexp.MustCompile(`(?i)^rm wire (?P<id>\d+)$`),
HelpText: "Removes a wire by ID (use list to view)",
Handler: p.rmWire},
bot.HandlerSpec{Kind: bot.Message, IsCmd: true,
Regex: regexp.MustCompile("(?i)^wire `(?P<parse>[^`]+)` to (?P<url>\\S+) `(?P<returnField>[^`]+)`$"),
HelpText: "Registers a new REST function",
Handler: p.handleWire},
}
p.b.RegisterTable(p, p.handlers)
wires, err := p.getWires()
if err != nil {
panic(err)
}
for _, w := range wires {
p.b.RegisterRegex(p, bot.Message, w.ParseRegex.Regexp, p.mkHandler(w))
}
}
type ScanableRegexp struct {
*regexp.Regexp
}
func (s *ScanableRegexp) Scan(src interface{}) error {
var source string
switch src.(type) {
case string:
source = src.(string)
default:
return errors.New("incompatible type for ScanableRegexp")
}
r, err := regexp.Compile(source)
if err != nil {
return err
}
s.Regexp = r
return nil
}
type ScanableURL struct {
*url.URL
}
func (s *ScanableURL) Scan(src interface{}) error {
var source string
switch src.(type) {
case string:
source = src.(string)
default:
return errors.New("incompatible type for ScanableURL")
}
u, err := url.Parse(source)
if err != nil {
return err
}
s.URL = u
return nil
}
type wire struct {
// ID
ID sql.NullInt64
// The URL to make a request to
URL ScanableURL
// The regex which will trigger this REST action
ParseRegex ScanableRegexp `db:"parse_regex"`
// The JSON field that will contain the REST return value
ReturnField string `db:"return_field"`
}
func (w wire) String() string {
msg := "Wire:"
msg += fmt.Sprintf("\nURL: %s", w.URL)
msg += fmt.Sprintf("\nParsing to trigger: `%s`", w.ParseRegex)
msg += fmt.Sprintf("\nReturn field: `%s`", w.ReturnField)
return msg
}
func (p *RestPlugin) getWires() ([]*wire, error) {
wires := []*wire{}
err := p.db.Select(&wires, `select * from wires`)
return wires, err
}
func (p *RestPlugin) deleteWire(id int64) error {
_, err := p.db.Exec(`delete from wires where id=?`, id)
return err
}
func (w *wire) Update(db *sqlx.DB) error {
if !w.ID.Valid {
return w.Save(db)
}
id, _ := w.ID.Value()
_, err := db.Exec(`update wires set url=?, parse_regex=?, return_field=? where id=?`,
w.URL.String(), w.ParseRegex.String(), w.ReturnField, id)
return err
}
func (w *wire) Save(db *sqlx.DB) error {
if w.ID.Valid {
return w.Update(db)
}
res, err := db.Exec(`insert into wires (url, parse_regex, return_field) values (?, ?, ?)`,
w.URL.String(), w.ParseRegex.String(), w.ReturnField)
if err != nil {
return err
}
id, err := res.LastInsertId()
if err != nil {
return err
}
_ = w.ID.Scan(id)
return nil
}
func (p *RestPlugin) listWires(r bot.Request) bool {
var msg string
wires, err := p.getWires()
if err != nil {
msg = err.Error()
goto SEND
}
msg = "Current wires:"
for _, w := range wires {
id, _ := w.ID.Value()
msg += fmt.Sprintf("\n\t%d: `%s` => %s", id, w.ParseRegex, w.URL)
}
SEND:
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, msg)
return true
}
func (p *RestPlugin) rmWire(r bot.Request) bool {
id, _ := strconv.ParseInt(r.Values["id"], 10, 64)
err := p.deleteWire(id)
if err != nil {
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, "Could not delete wire: "+err.Error())
return true
}
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, fmt.Sprintf("Deleted wire: %d", id))
return true
}
func (p *RestPlugin) handleWire(r bot.Request) bool {
var w wire
var msg string
var err error
w.ParseRegex.Regexp, err = regexp.Compile(r.Values["parse"])
if err != nil {
msg = err.Error()
goto SEND
}
w.URL.URL, err = url.Parse(r.Values["url"])
if err != nil {
msg = err.Error()
goto SEND
}
w.ReturnField = r.Values["returnField"]
err = w.Save(p.db)
if err != nil {
msg = err.Error()
goto SEND
}
p.b.RegisterRegex(p, bot.Message, w.ParseRegex.Regexp, p.mkHandler(&w))
msg = fmt.Sprintf("Saved %s", w)
SEND:
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, msg)
return true
}
func (p *RestPlugin) mkHandler(w *wire) bot.ResponseHandler {
return func(r bot.Request) bool {
if r.Msg.User.Name == p.b.Config().GetString("nick", "") {
return false
}
values := bot.RegexValues{}
for k := range r.Values {
values[k] = url.QueryEscape(r.Values[k])
}
urlStr := w.URL.String()
parse, err := template.New(urlStr).Parse(urlStr)
if p.handleErr(err, r) {
return true
}
buf := bytes.Buffer{}
err = parse.Execute(&buf, values)
if p.handleErr(err, r) {
return true
}
newURL, err := url.Parse(buf.String())
if p.handleErr(err, r) {
return true
}
resp, err := http.Get(newURL.String())
if p.handleErr(err, r) {
return true
}
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, fmt.Sprintf("Got a status %d: %s from %s",
resp.StatusCode, resp.Status, newURL))
}
body, err := ioutil.ReadAll(resp.Body)
if p.handleErr(err, r) {
return true
}
returnValues := map[string]string{}
json.Unmarshal(body, &returnValues)
var msg string
if text, ok := returnValues["text"]; ok {
msg = strings.TrimSpace(text)
} else {
msg = fmt.Sprintf("Wire handler did not find return value (%s): %s => `%s`", newURL.String(), w.URL, w.ReturnField)
}
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, msg)
return true
}
}
func (p *RestPlugin) handleErr(err error, r bot.Request) bool {
if err != nil {
p.b.Send(r.Conn, bot.Message, r.Msg.Channel, "Error: %s", err)
return true
}
return false
}