use axum::extract::{Json, Path, Query, State};
use chrono::{NaiveDate, NaiveDateTime};
use sea_orm::{
    prelude::*, DbBackend, FromQueryResult, ItemsAndPagesNumber, JoinType, Order, QueryOrder,
    QuerySelect, Statement,
};
use serde::{Deserialize, Serialize};

use crate::db::paginate::{paginate_also_related, PaginatedResponse};
use crate::error::AppError;
use crate::{model, AppState};

use super::{CompanySlug, Pagination};

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
pub struct TransactionCompany {
    pub id: i32,
    pub foreign_id: String,
    pub date_published: NaiveDate,
    pub date_executed: NaiveDate,
    pub person: String,
    pub exchange: String,
    pub nature: String,
    pub isin: Option<String>,
    pub instrument: String,
    pub volume: i32,
    pub unit_price: f32,
    pub created_at_utc: NaiveDateTime,
    pub company: Option<model::company::Model>,
}

pub async fn get_all(
    state: State<AppState>,
    Query(CompanySlug { company_slug }): Query<CompanySlug>,
    Query(Pagination { page, size }): Query<Pagination>,
) -> Result<Json<PaginatedResponse<TransactionCompany>>, AppError> {
    let db = &state.db;

    let mut filters = vec![];
    if let Some(c) = company_slug {
        filters.push(model::company::Column::Slug.eq(c))
    }

    let res = paginate_also_related::<
        model::transaction::Entity,
        model::company::Entity,
        model::transaction::Model,
        model::company::Model,
        model::transaction::Column,
    >(
        db,
        page,
        size,
        Some(model::transaction::Column::DatePublished),
        Some(Order::Desc),
        Some(filters),
    )
    .await?;

    let list = res
        .list
        .iter()
        .map(|t| TransactionCompany {
            id: t.0.id,
            foreign_id: t.0.foreign_id.to_owned(),
            date_published: t.0.date_published,
            date_executed: t.0.date_executed,
            person: t.0.person.to_owned(),
            exchange: t.0.exchange.to_owned(),
            nature: t.0.nature.to_owned(),
            isin: t.0.isin.clone(),
            instrument: t.0.instrument.to_owned(),
            volume: t.0.volume,
            unit_price: t.0.unit_price,
            created_at_utc: t.0.created_at_utc,
            company: t.1.to_owned(),
        })
        .collect();

    let res = PaginatedResponse {
        count: res.count,
        num_pages: res.num_pages,
        list,
    };

    Ok(Json(res))
}

#[derive(FromQueryResult, Serialize)]
pub struct LatestTransaction {
    company_name: String,
    slug: String,
    nature: String,
    total: f32,
}

pub async fn get_latest_transactions(
    state: State<AppState>,
    Query(pagination): Query<Pagination>,
) -> Result<Json<PaginatedResponse<LatestTransaction>>, AppError> {
    let db = &state.db;
    let s = pagination.size.unwrap_or(20).min(50);

    let query_raw = "SELECT 
        company.name as company_name,
        company.slug,
        transaction.nature,
        SUM(transaction.volume * transaction.unit_price) as total
        FROM transaction 
        JOIN company ON transaction.company_id = company.id 
        WHERE DATE(created_at_utc) IN (SELECT DATE(MAX(created_at_utc)) FROM transaction)
        GROUP BY company.name, transaction.nature
        ORDER BY transaction.nature, total DESC"
        .to_string();

    let query = model::transaction::Entity::find()
        .from_raw_sql(Statement::from_string(
            DbBackend::MySql,
            query_raw.to_string(),
        ))
        .into_model::<LatestTransaction>();

    let pages = query.paginate(db, s);

    let ItemsAndPagesNumber {
        number_of_items: count,
        number_of_pages: num_pages,
    } = pages.num_items_and_pages().await?;

    let p = pagination.page.unwrap_or(0).min(num_pages);

    let list = pages.fetch_page(p).await?;

    let res = PaginatedResponse {
        count,
        num_pages,
        list,
    };

    Ok(Json(res))
}

pub async fn get_aggregated_transactions(
    state: State<AppState>,
    pagination: Query<Pagination>,
) -> Result<Json<PaginatedResponse<TransactionsAggregated>>, AppError> {
    let db = &state.db;
    let s = pagination.0.size.unwrap_or(20).min(50);
    let query = model::company::Entity::find()
        .select_only()
        .join(
            JoinType::InnerJoin,
            model::company::Relation::Transaction.def(),
        )
        .column(model::company::Column::Id)
        .column(model::company::Column::Name)
        .column(model::company::Column::Slug)
        .column_as(model::transaction::Column::Id.count(), "transaction_count");

    let pages = query
        .group_by(model::company::Column::Name)
        .order_by(model::transaction::Column::Id.count(), Order::Desc)
        .into_model::<TransactionsAggregated>()
        .paginate(db, s);

    let ItemsAndPagesNumber {
        number_of_items: count,
        number_of_pages: num_pages,
    } = pages.num_items_and_pages().await?;

    let p = pagination.0.page.unwrap_or(0).min(num_pages);

    let list = pages.fetch_page(p).await?;

    let res = PaginatedResponse {
        count,
        num_pages,
        list,
    };

    Ok(Json(res))
}

#[derive(Serialize, FromQueryResult, Debug)]
pub struct TransactionsAggregated {
    id: i32,
    name: String,
    slug: String,
    transaction_count: i32,
}