// Copyright 2022-2024 - Nym Technologies SA <contact@nymtech.net>
// SPDX-License-Identifier: Apache-2.0

use crate::models::{
    BasicTicketbookInformation, EmergencyCredential, EmergencyCredentialContent,
    RawCoinIndexSignatures, RawExpirationDateSignatures, RawVerificationKey,
    StoredIssuedTicketbook, StoredPendingTicketbook,
};
use nym_ecash_time::Date;
use nym_sqlx_pool_guard::SqlitePoolGuard;
use sqlx::{Executor, Sqlite, Transaction};

#[derive(Clone)]
pub struct SqliteEcashTicketbookManager {
    connection_pool: SqlitePoolGuard,
}

impl SqliteEcashTicketbookManager {
    /// Creates new instance of the `EcashTicketbookManager` with the provided sqlite connection pool.
    ///
    /// # Arguments
    ///
    /// * `connection_pool`: database connection pool to use.
    pub fn new(connection_pool: SqlitePoolGuard) -> Self {
        SqliteEcashTicketbookManager { connection_pool }
    }

    /// Closes the connection pool.
    pub async fn close(&self) {
        self.connection_pool.close().await
    }

    pub(crate) async fn cleanup_expired(&self, deadline: Date) -> Result<(), sqlx::Error> {
        sqlx::query!(
            "DELETE FROM ecash_ticketbook WHERE expiration_date <= ?",
            deadline
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    /// Starts a write (IMMEDIATE) transaction, to prevent issue when upgrading from a read one to a write one
    pub(crate) async fn begin_storage_write_tx(
        &self,
    ) -> Result<Transaction<'_, Sqlite>, sqlx::Error> {
        self.connection_pool.begin_with("BEGIN IMMEDIATE").await
    }

    pub(crate) async fn insert_pending_ticketbook(
        &self,
        serialisation_revision: u8,
        deposit_id: u32,
        data: &[u8],
        expiration_date: Date,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT INTO pending_issuance
                (deposit_id, serialization_revision, pending_ticketbook_data, expiration_date)
                VALUES (?, ?, ?, ?)
            "#,
            deposit_id,
            serialisation_revision,
            data,
            expiration_date,
        )
        .execute(&*self.connection_pool)
        .await?;

        Ok(())
    }

    #[allow(clippy::too_many_arguments)]
    pub(crate) async fn insert_new_ticketbook(
        &self,
        serialisation_revision: u8,
        data: &[u8],
        expiration_date: Date,
        typ: &str,
        epoch_id: u32,
        total_tickets: u32,
        used_tickets: u32,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT INTO ecash_ticketbook
                (serialization_revision, ticketbook_data, expiration_date, ticketbook_type, epoch_id, total_tickets, used_tickets)
                VALUES (?, ?, ?, ?, ?, ?, ?)
            "#,
            serialisation_revision,
            data,
            expiration_date,
            typ,
            epoch_id,
            total_tickets,
            used_tickets,
        ).execute(&*self.connection_pool).await?;

        Ok(())
    }

    pub(crate) async fn contains_ticketbook_data(&self, data: &[u8]) -> Result<bool, sqlx::Error> {
        let exists = sqlx::query(
            r#"
                SELECT 1
                FROM ecash_ticketbook
                WHERE ticketbook_data = ?

            "#,
        )
        .bind(data)
        .fetch_optional(&*self.connection_pool)
        .await?
        .is_some();

        Ok(exists)
    }

    pub(crate) async fn get_ticketbooks_info(
        &self,
    ) -> Result<Vec<BasicTicketbookInformation>, sqlx::Error> {
        sqlx::query_as(
            r#"
                    SELECT id, expiration_date, ticketbook_type, epoch_id, total_tickets, used_tickets
                    FROM ecash_ticketbook
                "#,
        )
        .fetch_all(&*self.connection_pool)
        .await
    }

    pub(crate) async fn decrease_used_ticketbook_tickets(
        &self,
        ticketbook_id: i64,
        reverted_spent: u32,
        expected_current_total_spent: u32,
    ) -> Result<bool, sqlx::Error> {
        // the 'AND' clause will ensure this will only be executed if nobody else interacted with the row
        let affected = sqlx::query!(
            r#"
                UPDATE ecash_ticketbook
                SET used_tickets = used_tickets - ?
                WHERE id = ?
                AND used_tickets = ?
            "#,
            reverted_spent,
            ticketbook_id,
            expected_current_total_spent
        )
        .execute(&*self.connection_pool)
        .await?
        .rows_affected();
        Ok(affected > 0)
    }

    pub(crate) async fn get_pending_ticketbooks(
        &self,
    ) -> Result<Vec<StoredPendingTicketbook>, sqlx::Error> {
        sqlx::query_as("SELECT * FROM pending_issuance")
            .fetch_all(&*self.connection_pool)
            .await
    }

    pub(crate) async fn remove_pending_ticketbook(
        &self,
        pending_id: i64,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            "DELETE FROM pending_issuance WHERE deposit_id = ?",
            pending_id
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    pub(crate) async fn get_master_verification_key(
        &self,
        epoch_id: i64,
    ) -> Result<Option<RawVerificationKey>, sqlx::Error> {
        sqlx::query_as!(
            RawVerificationKey,
            r#"
                SELECT epoch_id as "epoch_id: u32", serialised_key, serialization_revision as "serialization_revision: u8"
                FROM master_verification_key WHERE epoch_id = ?
            "#,
            epoch_id
        )
        .fetch_optional(&*self.connection_pool)
        .await
    }

    pub(crate) async fn insert_master_verification_key(
        &self,
        serialisation_revision: u8,
        epoch_id: i64,
        data: &[u8],
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT OR IGNORE INTO master_verification_key(epoch_id, serialised_key, serialization_revision) VALUES (?, ?, ?);
                UPDATE master_verification_key
                    SET
                        serialised_key = ?,
                        serialization_revision = ?
                     WHERE epoch_id = ?
            "#,
            epoch_id,
            data,
            serialisation_revision,
            data,
            serialisation_revision,
            epoch_id
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    pub(crate) async fn get_coin_index_signatures(
        &self,
        epoch_id: i64,
    ) -> Result<Option<RawCoinIndexSignatures>, sqlx::Error> {
        sqlx::query_as!(
            RawCoinIndexSignatures,
            r#"
                SELECT epoch_id as "epoch_id: u32", serialised_signatures, serialization_revision as "serialization_revision: u8"
                FROM coin_indices_signatures WHERE epoch_id = ?
            "#,
            epoch_id
        )
        .fetch_optional(&*self.connection_pool)
        .await
    }

    pub(crate) async fn insert_coin_index_signatures(
        &self,
        serialisation_revision: u8,
        epoch_id: i64,
        data: &[u8],
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT OR IGNORE INTO coin_indices_signatures(epoch_id, serialised_signatures, serialization_revision) VALUES (?, ?, ?);
                UPDATE coin_indices_signatures
                    SET
                        serialised_signatures = ?,
                        serialization_revision = ?
                     WHERE epoch_id = ?
            "#,
            epoch_id,
            data,
            serialisation_revision,
            data,
            serialisation_revision,
            epoch_id,
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    pub(crate) async fn get_expiration_date_signatures(
        &self,
        expiration_date: Date,
        epoch_id: i64,
    ) -> Result<Option<RawExpirationDateSignatures>, sqlx::Error> {
        sqlx::query_as!(
            RawExpirationDateSignatures,
            r#"
                SELECT serialised_signatures, serialization_revision as "serialization_revision: u8"
                FROM expiration_date_signatures
                WHERE expiration_date = ? AND epoch_id = ?
            "#,
            expiration_date,
            epoch_id
        )
        .fetch_optional(&*self.connection_pool)
        .await
    }

    pub(crate) async fn insert_expiration_date_signatures(
        &self,
        serialisation_revision: u8,
        epoch_id: i64,
        expiration_date: Date,
        data: &[u8],
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT OR IGNORE INTO expiration_date_signatures(expiration_date, epoch_id, serialised_signatures, serialization_revision)
                VALUES (?, ?, ?, ?);
                UPDATE expiration_date_signatures
                    SET
                        serialised_signatures = ?,
                        serialization_revision = ?
                     WHERE expiration_date = ?
            "#,
            expiration_date,
            epoch_id,
            data,
            serialisation_revision,
            data,
            serialisation_revision,
            expiration_date
        )
            .execute(&*self.connection_pool)
            .await?;
        Ok(())
    }

    pub(crate) async fn get_emergency_credential(
        &self,
        typ: &str,
    ) -> Result<Option<EmergencyCredential>, sqlx::Error> {
        sqlx::query_as(
            r#"
                SELECT *
                FROM emergency_credential
                WHERE type = ?
                  AND (expiration IS NULL OR expiration > CURRENT_TIMESTAMP)
                ORDER BY expiration DESC NULLS LAST
                LIMIT 1
            "#,
        )
        .bind(typ)
        .fetch_optional(&*self.connection_pool)
        .await
    }

    pub(crate) async fn insert_emergency_credential(
        &self,
        credential: &EmergencyCredentialContent,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                INSERT INTO emergency_credential
                (type, content, expiration)
                VALUES (?, ?, ?)
                ON CONFLICT(type, content) DO NOTHING;
            "#,
            credential.typ,
            credential.content,
            credential.expiration,
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    pub(crate) async fn remove_emergency_credential(&self, id: i64) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                DELETE FROM emergency_credential
                WHERE id = ?
            "#,
            id
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }

    pub(crate) async fn remove_emergency_credentials_of_type(
        &self,
        typ: &str,
    ) -> Result<(), sqlx::Error> {
        sqlx::query!(
            r#"
                DELETE FROM emergency_credential
                WHERE type = ?
            "#,
            typ
        )
        .execute(&*self.connection_pool)
        .await?;
        Ok(())
    }
}

pub(crate) async fn get_next_unspent_ticketbook<'a, E>(
    executor: E,
    ticketbook_type: String,
    deadline: Date,
    tickets: u32,
) -> Result<Option<StoredIssuedTicketbook>, sqlx::Error>
where
    E: Executor<'a, Database = Sqlite>,
{
    sqlx::query_as(
        r#"
                SELECT *
                FROM ecash_ticketbook
                WHERE used_tickets + ? <= total_tickets
                AND expiration_date >= ?
                AND ticketbook_type = ?
                ORDER BY expiration_date ASC
                LIMIT 1
            "#,
    )
    .bind(tickets)
    .bind(deadline)
    .bind(ticketbook_type)
    .fetch_optional(executor)
    .await
}

pub(crate) async fn increase_used_ticketbook_tickets<'a, E>(
    executor: E,
    ticketbook_id: i64,
    extra_spent: u32,
) -> Result<(), sqlx::Error>
where
    E: Executor<'a, Database = Sqlite>,
{
    sqlx::query!(
        "UPDATE ecash_ticketbook SET used_tickets = used_tickets + ? WHERE id = ?",
        extra_spent,
        ticketbook_id
    )
    .execute(executor)
    .await?;
    Ok(())
}