KtIrc/src/main/kotlin/com/dmdirc/ktirc/messages/MessageBuilders.kt

package com.dmdirc.ktirc.messages

import com.dmdirc.ktirc.IrcClient
import com.dmdirc.ktirc.model.MessageTag

/** Sends a message to ask the server to list capabilities. */
internal fun IrcClient.sendCapabilityList() = send("CAP LS 302")

/** Sends a message indicating the end of capability negotiation. */
internal fun IrcClient.sendCapabilityEnd() = send("CAP END")

/** Sends a message requesting the specified caps are enabled. */
internal fun IrcClient.sendCapabilityRequest(capabilities: List<String>) = send("CAP REQ :${capabilities.joinToString(" ")}")

/** Sends a request to join the given channel. */
fun IrcClient.sendJoin(channel: String) = send("JOIN :$channel")

/** Sends a request to change to the given nickname. */
fun IrcClient.sendNickChange(nick: String) = send("NICK :$nick")

/** Sends the connection password to the server. */
internal fun IrcClient.sendPassword(password: String) = send("PASS :$password")

/** Sends a response to a PING event. */
internal fun IrcClient.sendPong(nonce: ByteArray) = send("PONG :${String(nonce)}")

/** Sends a CTCP message of the specified [type] and with optional [data] to [target] (a user or a channel). */
fun IrcClient.sendCtcp(target: String, type: String, data: String? = null) =
        sendMessage(target, "\u0001${type.toUpperCase()}${data?.let { " $it" } ?: ""}\u0001")

/** Sends an action to the given [target] (a user or a channel). */
fun IrcClient.sendAction(target: String, action: String) = sendCtcp(target, "ACTION", action)

/** Sends a private message to a user or channel. */
fun IrcClient.sendMessage(target: String, message: String, inReplyTo: String? = null) =
        sendWithTags(mapOf(MessageTag.Reply to inReplyTo), "PRIVMSG $target :$message")

/**
 * Sends a tag-only message.
 *
 * If [inReplyTo] is specified then the [MessageTag.Reply] tag will be automatically added.
 */
fun IrcClient.sendTagMessage(target: String, tags: Map<MessageTag, String>, inReplyTo: String? = null) {
    sendWithTags(inReplyTo?.let { tags + (MessageTag.Reply to inReplyTo) } ?: tags, "TAGMSG $target")
}

/** Sends a message to register a user with the server. */
internal fun IrcClient.sendUser(userName: String, realName: String) = send("USER $userName 0 * :$realName")

/** Starts an authentication request. */
internal fun IrcClient.sendAuthenticationMessage(data: String = "+") = send("AUTHENTICATE $data")

/**
 * Sends a message prefixed with some IRCv3 tags.
 *
 * For convenience, if the value of a tag is `null`, the tag will be omitted. If no tags are present the
 * message is sent directly with no prefix.
 */
internal fun IrcClient.sendWithTags(tags: Map<MessageTag, String?>, message: String) = tags
        .filterValues { it != null }
        .map { (key, value) -> "${key.name}=${value?.escapeTagValue()}" }
        .joinToString(";")
        .let {
            if (it.isEmpty()) send(message) else send("@$it $message")
        }

internal fun String.escapeTagValue() = replace("\\", "\\\\")
        .replace("\n", "\\n")
        .replace("\r", "\\r")
        .replace(";", "\\:")
        .replace(" ", "\\s")