<?php

namespace Slack;

use Carbon\Carbon;
use Carbon\CarbonInterface;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\Log;
use Slack\Jobs\DeleteChat;
use Slack\Models\{Channel,User};
use Slack\Blockkit\Block;
use Slack\Exceptions\SlackException;
use Slack\Message\Attachment;
use Slack\Response\Generic;

/**
 * This class is used when composing a message to send to Slack.
 */
class Message implements \JsonSerializable
{
	protected const LOGKEY = 'SM-';

	private $o;
	private $attachments;
	private $blocks;

	/**
	 * Message constructor.
	 *
	 * @param Model|null $o Who the message will be to - Channel or User
	 */
	public function __construct(Model $o=NULL)
	{
		$this->_data = collect();

		// Message is to a channel
		if ($o instanceof Channel) {
			$this->setChannel($o);

		// Message is to a user
		} elseif ($o instanceof User) {
			$this->setUser($o);
		}

		$this->o = $o;
		$this->attachments = collect();
		$this->blocks = collect();
	}

	/**
	 * Add an attachment to a message
	 *
	 * @param Attachment $attachment
	 * @return Message
	 */
	public function addAttachment(Attachment $attachment): self
	{
		$this->attachments->push($attachment);

		return $this;
	}

	/**
	 * Add a block to the message
	 *
	 * @param BlockKit $block
	 * @return $this
	 */
	public function addBlock(BlockKit $block): self
	{
		$this->blocks->push($block);

		return $this;
	}

	/**
	 * Empty the message
	 *
	 * @return $this
	 */
	public function blank(): self
	{
		$this->_data = collect();

		return $this;
	}

	/*
	 * @todo This doesnt appear to work
	public function ephemeral(): self
	{
		$this->_data->put('ephemeral',TRUE);

		return $this;
	}
	*/

	public function forgetTS(): self
	{
		$this->_data->forget('ts');

		return $this;
	}

	/**
	 * Return if this is an empty message
	 *
	 * @return bool
	 */
	public function isEmpty(): bool
	{
		return $this->jsonSerialize() ? FALSE : TRUE;
	}

	/**
	 * When we json_encode this object, this is the data that will be returned
	 */
	public function jsonSerialize()
	{
		if ($this->blocks->count()) {
			if ($this->_data->has('text'))
				throw new \Exception('Messages cannot have text and blocks!');

			$this->_data->put('blocks',$this->blocks);
		}

		if ($this->attachments->count())
			$this->_data->put('attachments',$this->attachments);

		// For interactive messages that generate a dialog, we need to return NULL
		return $this->_data->count() ? $this->_data : NULL;
	}

	/**
	 * Post this message to slack
	 *
	 * @param Carbon|null $delete
	 * @return Generic
	 * @throws \Exception
	 */
	public function post(Carbon $delete=NULL): Generic
	{
		if ($this->_data->has('ephemeral'))
			abort('500','Cannot post ephemeral messages.');

		$api = $this->o->team->slackAPI();
		$response = $this->_data->has('ts') ? $api->updateMessage($this) : $api->postMessage($this);

		if ($delete) {
			Log::debug(sprintf('%s:Scheduling Delete of [%s:%s] on [%s]',static::LOGKEY,object_get($this->o,'channel_id',$this->o->id),$response->ts,$delete->format('Y-m-d')),['m'=>__METHOD__]);

			// Queue the delete of the message if requested
			dispatch((new DeleteChat($this->o,$response->ts))->onQueue('low')->delay($delete));
		}

		return $response;
	}

	public function replace(bool $replace=TRUE): self
	{
		$this->_data['replace_original'] = $replace ? 'true' : 'false';

		return $this;
	}

	/**
	 * Post a message to slack using the respond_url
	 * @note This URL can only be used 5 times in 30 minutes
	 *
	 * @param string $url
	 */
	public function respond(string $url)
	{
		$request = curl_init();

		curl_setopt($request,CURLOPT_URL,$url);
		curl_setopt($request,CURLOPT_RETURNTRANSFER,TRUE);
		curl_setopt($request,CURLINFO_HEADER_OUT,TRUE);
		curl_setopt($request,CURLOPT_HTTPHEADER,['Content-Type: application/json; charset=utf-8']);
		curl_setopt($request,CURLOPT_SSL_VERIFYPEER,FALSE);
		curl_setopt($request,CURLOPT_POSTFIELDS,json_encode($this));

		try {
			$result = curl_exec($request);
			if (! $result)
				throw new \Exception('CURL exec returned an empty response: '.serialize(curl_getinfo($request)));

		} catch (\Exception $e) {
			Log::error(sprintf('%s:Got an error while posting to [%s] (%s)',static::LOGKEY,$url,$e->getMessage()),['m'=>__METHOD__]);

			throw new \Exception($e->getMessage());
		}

		if ($result !== 'ok') {
			switch ($result) {
				default:
					Log::critical(sprintf('%s:Generic Error',static::LOGKEY),['m'=>__METHOD__,'r'=>$result]);
					throw new SlackException($result,curl_getinfo($request,CURLINFO_HTTP_CODE));
			}
		}

		curl_close($request);
		return $result;
	}

	/**
	 * Make the message self destruct
	 *
	 * @param Carbon $time
	 * @return Generic
	 * @throws \Exception
	 */
	public function selfdestruct(Carbon $time): Generic
	{
		$this->addBlock(
			(new Block)->addContext(
				collect()
					->push((new BlockKit)->text(sprintf('This message will self destruct in %s...',$time->diffForHumans(Carbon::now(),['syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW]))))));

		return $this->post($time);
	}

	/**
	 * Set our channel
	 *
	 * @param Channel $o
	 * @return Message
	 */
	public function setChannel(Channel $o)
	{
		$this->_data['channel'] = $o->channel_id;

		return $this;
	}

	/**
	 * Set the icon next to the message
	 *
	 * @param string $icon
	 * @return $this
	 * @deprecated
	 */
	public function setIcon(string $icon): self
	{
		$this->_data->put('icon_emoji',$icon);

		return $this;
	}

	/**
	 * Option groups are used by the interactive Options controller and hold no other attributes
	 *
	 * @param array $array
	 * @return void
	 */
	public function setOptionGroup(array $array): void
	{
		$this->_data = collect();
		$this->_data->put('option_groups',$array);
	}

	/**
	 * Message text
	 *
	 * @param string $string
	 * @return $this
	 */
	public function setText(string $string): self
	{
		$this->_data->put('text',$string);

		return $this;
	}

	public function setTS(string $string): self
	{
		$this->_data->put('ts',$string);

		return $this;
	}

	public function setThreadTS(string $string): self
	{
		$this->_data->put('thread_ts',$string);

		return $this;
	}

	/**
	 * Set our channel
	 *
	 * @param User $o
	 * @return Message
	 */
	public function setUser(User $o)
	{
		$this->_data['channel'] = $o->user_id;

		return $this;
	}

	public function setUserName(string $user)
	{
		$this->_data['username'] = $user;

		return $this;
	}
}