use futures::StreamExt;
use serde::{Deserialize, Serialize};
use serde_json::json;
use sqlx::prelude::FromRow;

use crate::{get_itemdb, get_locations, get_pg, routes::ToAPI};

// todo : produced / consumed by flow field?

/// A Transaction of an Item Variant
#[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
pub struct Transaction {
    /// UUID
    pub id: uuid::Uuid,
    /// Associated Item
    pub item: String,
    /// Associated Variant
    pub variant: String,
    /// Price of obtaining the Item
    pub price: f64,
    /// Origin of the Item
    pub origin: Option<String>,
    /// The location of the Item
    pub location: Option<String>,
    /// Notes on Transaction
    pub note: Option<String>,
    /// Timestamp of the Transaction
    pub created: chrono::DateTime<chrono::Utc>,
    /// Destination of the Item or who consumed it
    pub destination: Option<String>,
    /// Price the Item was exported or consumed at
    pub consumed_price: Option<f64>,
    /// Timestamp of Consumption
    pub consumed_timestamp: Option<chrono::DateTime<chrono::Utc>>,
}

impl Transaction {
    pub async fn new(
        item: &str,
        variant: &str,
        price: f64,
        origin: Option<&str>,
        location: Option<&str>,
        note: Option<&str>,
    ) -> Self {
        sqlx::query_as("INSERT INTO transactions (item, variant, price, origin, location, note) VALUES ($1, $2, $3, $4, $5, $6) RETURNING *")
        .bind(item)
        .bind(variant)
        .bind(price)
        .bind(origin)
        .bind(location)
        .bind(note)
        .fetch_one(get_pg!()).await.unwrap()
    }

    pub async fn get(id: &uuid::Uuid) -> Option<Self> {
        sqlx::query_as("SELECT * FROM transactions WHERE id = $1")
            .bind(id)
            .fetch_optional(get_pg!())
            .await
            .unwrap()
    }

    /// Consumes the Item with `price` and `destination`
    pub async fn consume(self, price: f64, destination: &str) -> Self {
        sqlx::query_as(
"UPDATE transactions SET consumed_timestamp = current_timestamp, consumed_price = $1, destination = $2 WHERE id = $3 RETURNING *")
        .bind(price)
        .bind(destination)
        .bind(&self.id)
        .fetch_one(get_pg!()).await.unwrap()
    }

    pub async fn is_expired_at(&self, time: i64) -> bool {
        if let Some(expiry) = get_itemdb!()
            .get_item(&self.item)
            .unwrap()
            .variant(&self.variant)
            .unwrap()
            .expiry
        {
            let date_added = self.created.timestamp();

            let expiration_ts = expiry * 24 * 60 * 60;

            return (date_added + expiration_ts) < time;
        }

        false
    }

    pub async fn is_expired_in_days(&self, days: i64) -> bool {
        let current_time = chrono::Utc::now().timestamp();
        self.is_expired_at(current_time + (days * 24 * 60 * 60))
            .await
    }

    pub async fn is_expired(&self) -> bool {
        if self.consumed_timestamp.is_some() {
            if let Some(expiry) = get_itemdb!()
                .get_item(&self.item)
                .unwrap()
                .variant(&self.variant)
                .unwrap()
                .expiry
            {
                let time_around =
                    self.created.timestamp() - self.consumed_timestamp.unwrap().timestamp();
                let expiration_ts = expiry * 24 * 60 * 60;
                return time_around > expiration_ts;
            } else {
                return false;
            }
        }

        let current_time = chrono::Utc::now().timestamp();
        self.is_expired_at(current_time).await
    }

    pub async fn in_location(l: &str) -> Vec<Self> {
        sqlx::query_as(
            "SELECT * FROM transactions WHERE location = $1 AND consumed_timestamp IS NULL",
        )
        .bind(l)
        .fetch_all(get_pg!())
        .await
        .unwrap()
    }

    pub async fn in_location_recursive(l: &str) -> Option<Vec<Self>> {
        // get the children of this location
        let locations = get_locations!().get(l)?.children_recursive();

        let mut transactions = Self::in_location(l).await;

        for loc in locations {
            transactions.extend(Self::in_location(&loc.id).await);
        }

        Some(transactions)
    }

    /// Get all Transactions which are not consumed and are expired
    pub async fn active_expired(days: Option<i64>) -> Vec<Self> {
        let items: Vec<Self> = sqlx::query_as(
            "SELECT * FROM transactions WHERE consumed_timestamp IS NULL ORDER BY created DESC",
        )
        .fetch_all(get_pg!())
        .await
        .unwrap();

        let expired_items: Vec<_> = futures::stream::iter(items)
            .filter_map(|item| async move {
                let expired = if let Some(days) = days {
                    item.is_expired_in_days(days).await
                } else {
                    item.is_expired().await
                };

                if expired {
                    Some(item)
                } else {
                    None
                }
            })
            .collect()
            .await;

        expired_items
    }
}

impl ToAPI for Transaction {
    async fn api(&self) -> serde_json::Value {
        let location = if let Some(loc) = &self.location {
            Some(get_locations!().get(loc).unwrap().api().await)
        } else {
            None
        };

        let consumed = if self.consumed_timestamp.is_some() {
            Some(json!({
                "destination": self.destination,
                "price": self.consumed_price,
                "timestamp": self.consumed_timestamp.unwrap().timestamp()
            }))
        } else {
            None
        };

        json!({
            "uuid": self.id,
            "item": self.item,
            "variant": self.variant,
            "price": self.price,
            "origin": self.origin,
            "location": location,
            "timestamp": self.created.timestamp(),
            "consumed": consumed,
            "note": self.note,
            "expired": self.is_expired().await
        })
    }
}