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


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::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::MIN_CONVERSATION_MESSAGE_LENGTH;
use crate::controllers::user_ws_controller;
use crate::data::base_request_handler::BaseRequestHandler;
use crate::data::conversation::{ConversationMemberSetting, 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::UserID;
use crate::data::user_ws_connection::UserWsConnection;
use crate::data::user_ws_message::UserWsMessage;
use crate::helpers::{conversations_helper, events_helper, user_helper};
use crate::helpers::events_helper::Event;
use crate::routes::RequestResult;
use crate::utils::string_utils::remove_html_nodes;

/// Create a new conversation
pub fn create(r: &mut HttpRequestHandler) -> RequestResult {
    let name = r.post_string("name")?;
    let mut members = r.post_numbers_list("users", 1)?
        .iter()
        .map(|f| UserID::new(f.clone()))
        .collect::<Vec<UserID>>();

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

    // Check if members exists
    for user in &members {
        if !user_helper::exists(user)? {
            r.not_found(format!("User {} not found!", user.id()))?;
        }
    }

    // Add current user ID if required
    let curr_user_id = r.user_id()?;
    if !members.contains(&curr_user_id) {
        members.push(curr_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,
        background: None,// TODO : add support for background
    };

    // 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")?;
    let conv = conversations_helper::get_single(conv_membership.conv_id)?;

    // 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")?,
        )?;
    }

    // Update members list
    if r.has_post_parameter("members") && !conv.is_managed() {
        let mut members = r.post_users_id("members")?
            .into_iter()
            .map(|user_id| ConversationMemberSetting { user_id, set_admin: false })
            .collect::<Vec<ConversationMemberSetting>>();
        let admins = r.post_users_id("admins")?;

        let can_everyone_add_members = conversations_helper::can_everyone_add_members(conv_membership.conv_id)?;

        if !conv_membership.is_admin && !can_everyone_add_members {
            r.forbidden("You can not update the list of members of this conversation!".to_string())?;
        }

        // Set same admin status as earlier
        if !conv_membership.is_admin {
            members = members
                .into_iter()
                .map(|mut n| {
                    n.set_admin = conv.is_admin(&n.user_id);
                    n
                })
                .collect()
        }

        // If the user is an admin, use the values he gave
        else {
            members = members
                .into_iter()
                .map(|mut n| {
                    n.set_admin = admins.contains(&n.user_id);
                    n
                })
                .collect()
        }

        // Current user can not touch his own membership, so revert it back forcefully
        members = members
            .into_iter()
            .filter(|m| !m.user_id.eq(&conv_membership.user_id))
            .collect::<Vec<ConversationMemberSetting>>();

        members.push(ConversationMemberSetting {
            user_id: r.user_id()?,
            set_admin: conv_membership.is_admin,
        });


        conversations_helper::set_members(conv_membership.conv_id, &members, conv_membership.is_admin)?;
    }

    // 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!")
}

/// 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 new_conv = NewConversation {
            owner_id: r.user_id()?,
            name: None,
            owner_following: true,
            members: vec![r.user_id()?, other_user],
            can_everyone_add_members: true,
            color: r.post_color_opt("color")?,
            background: 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 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)?,
    };

    if messages.len() > 0 {
        conversations_helper::mark_user_seen(
            conv.conv_id,
            r.user_id_ref()?,
            messages.iter().map(|m| m.id).max().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")?;

    // TODO : add support for other files type

    // Get image
    let file = match r.has_file("image") {
        false => None,
        true => {
            let path = r.save_post_image("image", "conversations", 1200, 1200)?;
            Some(ConversationMessageFile {
                path: path.clone(),
                size: std::fs::metadata(&path)?.len(),
                name: "picture.png".to_string(),
                thumbnail: Some(r.save_post_image("image", "conversations", 50, 50)?),
                r#type: "image/png".to_string(),
            })
        }
    };

    let message = if let None = file {
        Some(r.post_string_without_html("message", MIN_CONVERSATION_MESSAGE_LENGTH, true)?)
    } 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", 3, true)?;

    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::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.id)),
            )?;
        }

        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(&_) -> _>,
            )?;
        }

        _ => {}
    }

    Ok(())
}