// OpenSAPS - Open Slack API server for everyone.
//
// Copyright (c) 2017, Stanislav N. aka pztrn.
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
package slack

// This is a handler for Slack Webhooks API requests.
// Slack Webhooks API generates next URL:
//      https://hooks.slack.com/services/TRANDOM1/BRANDOM2/randomlongstring
//
// Where:
//   * RANDOM1 and RANDOM2 - random 8-char thing.
//   * randomlongstring - random 24-char thing.
//
// These strings should be defined in configuration, so we can create proper
// handler for it.

import (
    // stdlib
    "fmt"
    "net/http"
    "time"
)

type SlackAPIServer struct {}

func (sh SlackAPIServer) Initialize() {
    c.Log.Infoln("Initializing Slack API handler...")

    // Start HTTP server.
    // As OpenSAPS designed to be behind some proxy (nginx, Caddy, etc.)
    // we will listen only to plain HTTP.
    // Note to those who wants HTTPS - proxify with nginx, Caddy, etc!
    // Don't send pull requests, patches, don't create issues! :)
    cfg := c.Config.GetConfig()

    httpsrv = &http.Server{
        Addr:           cfg.SlackHandler.Listener.Address,
        // This handler will figure out from where request has come and will
        // send it to approriate pusher. Pusher should also determine to which
        // connection data should be sent.
        Handler:        SlackHandler{},
        ReadTimeout:    10 * time.Second,
        WriteTimeout:   10 * time.Second,
        MaxHeaderBytes: 1 << 20,
    }

    go httpsrv.ListenAndServe()
    c.Log.Infof("Slack Webhooks API server starting to listen on %s", cfg.SlackHandler.Listener.Address)
}

func (sh SlackAPIServer) handleRequest(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, %q", r.URL.Path)
}

func (sh SlackAPIServer) Shutdown() {
    c.Log.Infoln("Shutting down Slack API handler...")
    httpsrv.Shutdown(nil)
    c.Log.Infoln("Slack API HTTP server shutted down")
}