//! # Conversations controller
//!
//! @author Pierre Hubert

use std::collections::HashSet;

use crate::api_data::conversation_api::ConversationAPI;
use crate::api_data::conversation_message_api::ConversationMessageAPI;
use crate::api_data::list_unread_conversations_api::UnreadConversationAPI;
use crate::api_data::remove_user_from_conv_message::RemovedUserFromConversationMessage;
use crate::api_data::res_count_unread_conversations::ResultCountUnreadConversations;
use crate::api_data::res_create_conversation::ResCreateConversation;
use crate::api_data::res_find_private_conversations::ResFindPrivateConversations;
use crate::constants::{ALLOWED_CONVERSATION_FILES_TYPES, CONVERSATION_FILES_MAX_SIZE, MAX_CONVERSATION_MESSAGE_LENGTH, MIN_CONVERSATION_MESSAGE_LENGTH};
use crate::controllers::user_ws_controller;
use crate::data::base_request_handler::{BaseRequestHandler, RequestValue};
use crate::data::conversation::NewConversationSettings;
use crate::data::conversation_message::ConversationMessageFile;
use crate::data::error::Res;
use crate::data::http_request_handler::HttpRequestHandler;
use crate::data::new_conversation::NewConversation;
use crate::data::new_conversation_message::NewConversationMessage;
use crate::data::user_ws_connection::UserWsConnection;
use crate::data::user_ws_message::UserWsMessage;
use crate::helpers::{conversations_helper, events_helper};
use crate::helpers::events_helper::Event;
use crate::routes::RequestResult;
use crate::utils::string_utils::remove_html_nodes;
use crate::utils::user_data_utils::{delete_user_data_file_if_exists, user_data_path};

/// Create a new conversation
pub fn create(r: &mut HttpRequestHandler) -> RequestResult {
    let name = r.post_string("name")?;
    let mut members = r.post_users_id("users")?;

    // Adapt name
    let name = match name.as_str() {
        "false" => None,
        s => Some(s.to_string())
    };

    // Add current user ID if required
    members.insert(r.user_id()?);

    let conv = NewConversation {
        owner_id: r.user_id()?,
        name,
        owner_following: r.post_bool("follow")?,
        members,
        can_everyone_add_members: r.post_bool_opt("canEveryoneAddMembers", true),
        color: r.post_color_opt("color")?,
        group_id: None,
        logo: None,
    };

    // Create the conversation
    let conv_id = conversations_helper::create(&conv)?;
    r.set_response(ResCreateConversation::new(conv_id))
}

/// Get the list of conversations of a user
pub fn get_list(r: &mut HttpRequestHandler) -> RequestResult {
    let list = conversations_helper::get_list_user(&r.user_id()?)?;

    r.set_response(list.iter().map(|c| ConversationAPI::new(c)).collect::<Vec<ConversationAPI>>())
}

/// Get information about a single conversation
pub fn get_single(r: &mut HttpRequestHandler) -> RequestResult {
    let conv = r.post_conv("conversationID")?;
    let conv = conversations_helper::get_single(conv.conv_id)?;

    r.set_response(ConversationAPI::new(&conv))
}

/// Update the settings of a conversation
pub fn update_settings(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv("conversationID")?;

    // Update following state, if required
    if r.has_post_parameter("following") {
        conversations_helper::set_following(
            &r.user_id()?,
            conv_membership.conv_id,
            r.post_bool("following")?,
        )?;
    }

    // Change moderator settings
    if r.has_post_parameter("name")
        && r.has_post_parameter("canEveryoneAddMembers")
        && r.has_post_parameter("color") {
        if !conv_membership.is_admin {
            r.forbidden("You are not allowed to perform changes on this conversation!".to_string())?;
        }


        let new_settings = NewConversationSettings {
            conv_id: conv_membership.conv_id,
            name: r.post_string_optional("name").map(|s| remove_html_nodes(&s)),
            color: r.post_color_opt("color")?,
            can_everyone_add_members: r.post_bool("canEveryoneAddMembers")?,
        };

        conversations_helper::set_settings(new_settings)?;
    }

    r.success("Conversation information successfully updated!")
}

/// Change conversation image
pub fn change_image(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv_admin("convID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    let new_image = r.save_post_image("file", "conv-image", 200, 200)?;

    conversations_helper::remove_conversation_image(&conv)?;

    conversations_helper::set_conversation_image(&conv, &new_image)?;

    r.ok()
}

/// Delete conversation image
pub fn delete_image(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv_admin("convID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    conversations_helper::remove_conversation_image(&conv)?;

    r.ok()
}

/// Add a new member to a conversation
pub fn add_member(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv("convID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    let user_to_add = r.post_user_id("userID")?;

    if conv.is_managed() {
        r.bad_request("This conversation is managed, you can not manually change its members!".to_string())?;
    }

    if !conv.can_user_add_members(r.user_id_ref()?) {
        r.forbidden("You are not allowed to add members to this conversation!".to_string())?;
    }

    if conv.get_membership(&user_to_add).is_some() {
        r.bad_request("This user is already a member of this conversation!".to_string())?;
    }

    conversations_helper::add_member(conv.id, &user_to_add, true, false, r.user_id_ref()?)?;

    r.success("The user was added to the conversation!")
}

/// Update admin status of a user
pub fn set_admin(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv_admin("convID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;
    let user_to_update = r.post_user_id("userID")?;
    let set_admin = r.post_bool("setAdmin")?;

    if conv.is_managed() {
        r.bad_request("This conversation is managed, you can not manually change its members!".to_string())?;
    }

    if !conv.can_mark_other_users_admin(r.user_id_ref()?) {
        r.forbidden("You are not allowed to make users admin in this conversation!".to_string())?;
    }

    if conv.get_membership(&user_to_update).is_none() {
        r.bad_request("This user is not a member of this conversation!".to_string())?;
    }

    conversations_helper::set_admin(&conv.id, &user_to_update, set_admin)?;

    r.success("The user was added to the conversation!")
}

/// Remove a member from a conversation
pub fn remove_member(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv_admin("convID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    let user_to_remove = r.post_user_id("userID")?;

    if conv.is_managed() {
        r.bad_request("This conversation is managed, you can not manually change its members!".to_string())?;
    }

    if !conv.can_user_remove_members(r.user_id_ref()?) {
        r.forbidden("You are not allowed to remove members from this conversation!".to_string())?;
    }

    if conv.get_membership(&user_to_remove).is_none() {
        r.bad_request("This user is not a member of this conversation!".to_string())?;
    }

    conversations_helper::remove_member(&user_to_remove, conv.id, r.user_id_ref()?)?;

    r.ok()
}

/// Find a private conversation
pub fn find_private(r: &mut HttpRequestHandler) -> RequestResult {
    let other_user = r.post_user_id("otherUser")?;
    let allow_create = r.post_bool_opt("allowCreate", false);

    // Query the database
    let mut list = conversations_helper::find_private(&r.user_id()?, &other_user)?;

    if list.is_empty() {
        if !allow_create {
            return r.not_found(format!("Not any private conversation was found. The server was not allowed to create a new one..."));
        }

        let mut members = HashSet::new();
        members.insert(r.user_id()?);
        members.insert(r.user_id()?);

        let new_conv = NewConversation {
            owner_id: r.user_id()?,
            name: None,
            owner_following: true,
            members,
            can_everyone_add_members: true,
            color: None,
            logo: None,
            group_id: None,
        };
        let conv_id = conversations_helper::create(&new_conv)?;
        list.push(conv_id);
    }

    r.set_response(ResFindPrivateConversations::new(list))
}

/// Refresh a single conversation
pub fn refresh_single(r: &mut HttpRequestHandler) -> RequestResult {
    let conv = r.post_conv("conversationID")?;
    let last_message_id = r.post_u64("last_message_id")?;

    let mut messages = match last_message_id {
        // Get latest messages of the conversation
        0 => conversations_helper::get_last_messages(conv.conv_id, 10)?,

        // Get new messages
        _ => conversations_helper::get_new_messages(conv.conv_id, last_message_id)?,
    };

    messages.sort_by(|one, two| one.id.cmp(&two.id));

    if messages.len() > 0 && messages.last().unwrap().id > conv.last_message_seen {
        conversations_helper::mark_user_seen(
            conv.conv_id,
            r.user_id_ref()?,
            &messages.last().unwrap(),
        )?;
    }

    r.set_response(ConversationMessageAPI::for_list(&messages))
}

/// Get older messages of a conversation
pub fn get_older_messages(r: &mut HttpRequestHandler) -> RequestResult {
    let conv = r.post_conv("conversationID")?;
    let max_id = r.post_u64("oldest_message_id")? - 1;

    // Determine limit
    let limit = r.post_u64("limit")?;
    let limit = match limit {
        0 => 1,
        1..=60 => limit,
        _ => 60
    };

    let messages = conversations_helper::get_older_messages(conv.conv_id, max_id, limit)?;

    r.set_response(ConversationMessageAPI::for_list(&messages))
}

/// Send a new message
pub fn send_message(r: &mut HttpRequestHandler) -> RequestResult {
    let conv = r.post_conv("conversationID")?;

    // Get associated file
    let file = match r.post_parameter_opt("file") {
        Some(RequestValue::File(file)) => {

            // File name
            let mut name = file.name.to_string();

            if file.buff.len() > CONVERSATION_FILES_MAX_SIZE {
                r.bad_request("File is too big!".to_string())?;
            }

            // Determine file mime type
            let mut mime_type = r.post_file_type("file")?;

            // Check for thumbnail
            let mut thumbnail = match r.has_file("thumbnail") {
                false => None,
                true => Some("thumbnail".to_string())
            };

            let path;

            if !ALLOWED_CONVERSATION_FILES_TYPES.contains(&mime_type.as_str()) {
                r.bad_request("File type is not allowed!".to_string())?;
            }

            // Images
            if mime_type.starts_with("image/") {
                if let None = thumbnail {
                    thumbnail = Some("file".to_string());
                }

                path = r.save_post_image("file", "conversation", 2000, 2000)?;
                mime_type = "image/png".to_string();
                name = "picture.png".to_string();
            }

            // PDF
            else if mime_type.eq("application/pdf") {
                path = r.save_post_pdf("file", "conversation")?;
            }

            // MP3
            else if mime_type.eq("audio/mpeg") {
                path = r.save_post_mp3("file", "conversation")?;
            }

            // MP4
            else if mime_type.eq("video/mp4") {
                path = r.save_post_mp4("file", "conversation")?;
            }

            // ZIP archive
            else if mime_type.eq("application/zip") {
                path = r.save_post_zip("file", "conversation")?;
            }

            // Office document
            else if mime_type.starts_with("application/") {
                path = r.save_post_office_doc("file", "conversation")?;
            }

            // Text files
            else {
                path = r.save_post_txt_doc("file", "conversation")?;
            }


            // Attempt to save thumbnail, if it fails we can not save message
            let thumbnail = match thumbnail {
                None => None,
                Some(f) => Some(match r.save_post_image(&f, "conversations-thumb", 200, 200) {
                    Ok(s) => Ok(s),
                    Err(e) => {
                        eprintln!("Failed to save conversation thumbnail! {:#?}", e);
                        delete_user_data_file_if_exists(&path).unwrap();
                        Err(e)
                    }
                }?)
            };


            Some(ConversationMessageFile {
                path: path.clone(),
                size: std::fs::metadata(user_data_path(path.as_ref()))?.len(),
                name,
                thumbnail,
                r#type: mime_type,
            })
        }
        _ => None,
    };

    // Get message, if there is no file
    let message = if let None = file {
        let msg = r.post_string_without_html("message", MIN_CONVERSATION_MESSAGE_LENGTH, true)?;

        if msg.len() > MAX_CONVERSATION_MESSAGE_LENGTH {
            r.bad_request("Message is too long!".to_string())?;
        }

        Some(msg)
    } else {
        None
    };

    conversations_helper::send_message(&NewConversationMessage {
        user_id: Some(r.user_id()?),
        conv_id: conv.conv_id,
        message,
        file,
        server_message: None,
    })?;

    r.success("Conversation message was successfully sent!")
}

/// Count the number of unread conversation of the user
pub fn count_unread(r: &mut HttpRequestHandler) -> RequestResult {
    let num = conversations_helper::count_unread_for_user(&r.user_id()?)?;

    r.set_response(ResultCountUnreadConversations::new(num))
}

/// Get the list of unread conversations of a user
pub fn list_unread(r: &mut HttpRequestHandler) -> RequestResult {
    let list = conversations_helper::get_list_unread(&r.user_id()?)?;

    r.set_response(UnreadConversationAPI::for_list(&list)?)
}

/// Delete a conversation
pub fn delete_conversation(r: &mut HttpRequestHandler) -> RequestResult {
    let conv_membership = r.post_conv("conversationID")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    if conv.is_managed() {
        r.bad_request("This conversation is managed, it can not be deleted by this way!".to_string())?;
    }

    conversations_helper::remove_user_from_conversation(&r.user_id()?, &conv, r.user_id_ref()?)?;

    r.success("The conversation has been deleted")
}

/// Update a single conversation message
pub fn update_message(r: &mut HttpRequestHandler) -> RequestResult {
    let msg_id = r.post_u64("messageID")?;
    let new_content = r.post_string_opt("content", MIN_CONVERSATION_MESSAGE_LENGTH, true)?;

    let msg = conversations_helper::get_single_message(msg_id)?;

    if msg.user_id != r.user_id_opt() {
        r.forbidden("You are not the owner of this message!".to_string())?;
    }

    if msg.file.is_some() {
        r.bad_request("Can not have both text and file in the same message!".to_string())?;
    }

    if new_content.len() > MAX_CONVERSATION_MESSAGE_LENGTH {
        r.bad_request("New message is too long!".to_string())?;
    }

    conversations_helper::update_message_content(msg_id, &new_content)?;

    r.success("Conversation message content successfully updated")
}

/// Delete a conversation message
pub fn delete_message(r: &mut HttpRequestHandler) -> RequestResult {
    let msg_id = r.post_u64("messageID")?;

    if !conversations_helper::is_message_owner(&r.user_id()?, msg_id)? {
        r.forbidden("You are not the owner of this message!".to_string())?;
    }

    conversations_helper::delete_message_by_id(msg_id)?;

    r.success("The message has been successfully deleted!")
}

/// Events handler
pub fn handle_event(e: &events_helper::Event) -> Res {
    match e {
        Event::UpdatedNumberUnreadConversations(users) => {
            for user in users.iter() {
                if user_ws_controller::is_user_connected(user) {
                    user_ws_controller::send_message_to_user(
                        &UserWsMessage::no_id_message(
                            "number_unread_conversations",
                            conversations_helper::count_unread_for_user(user)?,
                        )?,
                        user,
                    )?;
                }
            }
        }

        Event::NewConversationMessage(msg) => {
            user_ws_controller::send_message_to_specific_connections(
                |f| f.conversations.contains(&msg.conv_id),
                |_| UserWsMessage::no_id_message("new_conv_message", ConversationMessageAPI::new(msg)),
                Some(|conn: &UserWsConnection| conversations_helper::mark_user_seen(msg.conv_id, conn.user_id(), msg)),
            )?;
        }

        Event::UpdatedConversationMessage(msg) => {
            user_ws_controller::send_message_to_specific_connections(
                |f| f.conversations.contains(&msg.conv_id),
                |_| UserWsMessage::no_id_message("updated_conv_message", ConversationMessageAPI::new(msg)),
                None::<fn(&_) -> _>,
            )?;
        }

        Event::DeleteConversationMessage(msg) => {
            user_ws_controller::send_message_to_specific_connections(
                |f| f.conversations.contains(&msg.conv_id),
                |_| UserWsMessage::no_id_message("deleted_conv_message", ConversationMessageAPI::new(msg)),
                None::<fn(&_) -> _>,
            )?;
        }

        Event::RemovedUserFromConversation(user_id, conv_id) => {
            // Notify users
            user_ws_controller::send_message_to_specific_connections(
                |f| f.conversations.contains(conv_id),
                |_| UserWsMessage::no_id_message("removed_user_from_conv", RemovedUserFromConversationMessage::new(user_id, *conv_id)),
                None::<fn(&_) -> _>,
            )?;

            // Disconnect users from conversation
            user_ws_controller::foreach_connection(|f| {
                if f.user_id() == user_id && f.conversations.contains(conv_id) {
                    f.clone().replace(|w| {
                        w.conversations.remove(conv_id);
                    });
                }

                Ok(())
            })?;
        }

        _ => {}
    }

    Ok(())
}