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

use crate::data::new_conversation::NewConversation;
use crate::data::error::{ResultBoxError, ExecError};
use crate::helpers::database::{InsertQuery};
use crate::constants::database_tables_names::{CONV_LIST_TABLE, CONV_USERS_TABLE};
use crate::utils::date_utils::time;
use crate::data::user::UserID;
use crate::data::conversation::Conversation;
use crate::helpers::database;

/// Create a new conversation. This method returns the ID of the created conversation
pub fn create(conv: &NewConversation) -> ResultBoxError<u64> {
    // Create the conversation in the main table
    let conv_id = InsertQuery::new(CONV_LIST_TABLE)
        .add_user_id("user_id", conv.owner_id)
        .add_str("name", conv.name.clone().unwrap_or(String::new()).as_str())
        .add_u64("last_active", time())
        .add_u64("creation_time", time())
        .add_legacy_bool("can_everyone_add_members", conv.can_everyone_add_members)
        .insert()?.ok_or(ExecError::new("missing result conv id!"))?;

    // Add the members to the conversation
    for member in &conv.members {
        // Check following status of the member
        let mut follow = true;
        if member.eq(&conv.owner_id) {
            follow = conv.owner_following;
        }

        add_member(conv_id, member.clone(), follow)?;
    }

    Ok(conv_id)
}

/// Add a member to a conversation
pub fn add_member(conv_id: u64, user_id: UserID, following: bool) -> ResultBoxError<()> {
    InsertQuery::new(CONV_USERS_TABLE)
        .add_u64("conv_id", conv_id)
        .add_user_id("user_id", user_id)
        .add_u64("time_add", time())
        .add_legacy_bool("following", following)
        .add_legacy_bool("saw_last_message", true)
        .insert()?;

    Ok(())
}

/// Get the list of conversations of a specific user
pub fn get_list_user(user_id: UserID) -> ResultBoxError<Vec<Conversation>> {
    database::QueryInfo::new(CONV_LIST_TABLE)
        .alias("l")

        // Join with conversation members table
        .join(CONV_USERS_TABLE, "u", "l.id = u.conv_id")

        // Specify selected fields
        .add_field("*")
        .add_field("l.id as id")
        .add_field("l.user_id as owner_id")

        // Filter query
        .cond_user_id("u.user_id", user_id)

        // Sort results
        .set_order("l.last_active DESC")

        // Execute query
        .exec(db_to_conversation_info)
}

/// Get information about a single conversation
pub fn get_single(conv_id: u64, user_id: UserID) -> ResultBoxError<Conversation> {
    // Tables
    database::QueryInfo::new(CONV_LIST_TABLE)
        .alias("l")
        .join(CONV_USERS_TABLE, "u", "l.id = u.conv_id")

        // Fields
        .add_field("*")
        .add_field("l.id as id")
        .add_field("l.user_id as owner_id")

        // Conditions
        .cond_u64("l.id", conv_id)
        .cond_user_id("u.user_id", user_id)

        .query_row(db_to_conversation_info)
}

/// Get the list of members of a conversation
pub fn get_list_members(conv_id: u64) -> ResultBoxError<Vec<UserID>> {
    database::QueryInfo::new(CONV_USERS_TABLE)
        .cond_u64("conv_id", conv_id)
        .add_field("user_id")
        .exec(|res| res.get_user_id("user_id"))
}

/// Check if a user belongs to a conversation or not
pub fn does_user_belongs_to(user_id: UserID, conv_id: u64) -> ResultBoxError<bool> {
    Ok(database::QueryInfo::new(CONV_USERS_TABLE)
        .cond_u64("conv_id", conv_id)
        .cond_user_id("user_id", user_id)
        .exec_count()? > 0)
}

/// Check out wheter a user is the moderator of a conversation or not
pub fn is_user_moderator(user_id: UserID, conv_id: u64) -> ResultBoxError<bool> {
    Ok(database::QueryInfo::new(CONV_LIST_TABLE)
        .cond_u64("id", conv_id)
        .cond_user_id("user_id", user_id)
        .exec_count()? > 0)
}

/// Turn a database entry into a ConversationInfo object
fn db_to_conversation_info(row: &database::RowResult) -> ResultBoxError<Conversation> {
    let conv_id = row.get_u64("id")?;
    Ok(Conversation {
        id: conv_id,
        owner_id: row.get_user_id("owner_id")?,
        name: row.get_optional_str("name")?,
        members: get_list_members(conv_id)?,
        can_everyone_add_members: row.get_legacy_bool("can_everyone_add_members")?,
        last_active: row.get_u64("last_active")?,
        time_create: row.get_u64("time_add")?,
        following: row.get_legacy_bool("following")?,
        saw_last_message: row.get_legacy_bool("saw_last_message")?,
    })
}