Swiftgram/TelegramCore/SearchMessages.swift

import Foundation
import SwiftSignalKit
import Postbox

private func locallyRenderedMessage(message: StoreMessage, peers: [PeerId: Peer]) -> Message? {
    guard case let .Id(id) = message.id else {
        return nil
    }
    
    var messagePeers = SimpleDictionary<PeerId, Peer>()
    
    var author: Peer?
    if let authorId = message.authorId {
        author = peers[authorId]
        if let author = author {
            messagePeers[author.id] = author
        }
    }
    
    if let peer = peers[id.peerId] {
        messagePeers[peer.id] = peer
    }
    
    return Message(stableId: 0, id: id, timestamp: message.timestamp, flags: MessageFlags(message.flags), tags: message.tags, forwardInfo: nil, author: author, text: message.text, attributes: message.attributes, media: message.media, peers: messagePeers, associatedMessages: SimpleDictionary())
}

public func searchMessages(account: Account, query: String) -> Signal<[Message], NoError> {
    let searchResult = account.network.request(Api.functions.messages.searchGlobal(q: query, offsetDate: 0, offsetPeer: Api.InputPeer.inputPeerEmpty, offsetId: 0, limit: 64))
        |> retryRequest
    
    let processedSearchResult = searchResult
        |> mapToSignal { result -> Signal<[Message], NoError> in
            let messages: [Api.Message]
            let chats: [Api.Chat]
            let users: [Api.User]
            switch result {
                case let .channelMessages(_, _, _, apiMessages, apiChats, apiUsers):
                    messages = apiMessages
                    chats = apiChats
                    users = apiUsers
                case let .messages(apiMessages, apiChats, apiUsers):
                    messages = apiMessages
                    chats = apiChats
                    users = apiUsers
                case let.messagesSlice(_, apiMessages, apiChats, apiUsers):
                    messages = apiMessages
                    chats = apiChats
                    users = apiUsers
            }
            
            return account.postbox.modify { modifier -> [Message] in
                var peers: [PeerId: Peer] = [:]
                
                for user in users {
                    if let user = TelegramUser.merge(modifier.getPeer(user.peerId) as? TelegramUser, rhs: user) {
                        peers[user.id] = user
                    }
                }
                
                for chat in chats {
                    if let group = TelegramGroup.merge(modifier.getPeer(chat.peerId) as? TelegramGroup, rhs: chat) {
                        peers[group.id] = group
                    }
                }
                
                var renderedMessages: [Message] = []
                for message in messages {
                    if let message = StoreMessage(apiMessage: message), let renderedMessage = locallyRenderedMessage(message: message, peers: peers) {
                        renderedMessages.append(renderedMessage)
                    }
                }
                
                return renderedMessages
            }
            
        }
    
    return processedSearchResult
}