use bitcoin::hash_types::Txid;
use bitcoin::{OutPoint, Script, Transaction, TxOut};

use crate::error::Error;
use crate::types::*;

#[cfg(any(feature = "key-value-db", feature = "default"))]
pub mod keyvalue;
pub mod memory;

pub trait BatchOperations {
    fn set_script_pubkey(
        &mut self,
        script: &Script,
        script_type: ScriptType,
        child: u32,
    ) -> Result<(), Error>;
    fn set_utxo(&mut self, utxo: &UTXO) -> Result<(), Error>;
    fn set_raw_tx(&mut self, transaction: &Transaction) -> Result<(), Error>;
    fn set_tx(&mut self, transaction: &TransactionDetails) -> Result<(), Error>;
    fn set_last_index(&mut self, script_type: ScriptType, value: u32) -> Result<(), Error>;

    fn del_script_pubkey_from_path(
        &mut self,
        script_type: ScriptType,
        child: u32,
    ) -> Result<Option<Script>, Error>;
    fn del_path_from_script_pubkey(
        &mut self,
        script: &Script,
    ) -> Result<Option<(ScriptType, u32)>, Error>;
    fn del_utxo(&mut self, outpoint: &OutPoint) -> Result<Option<UTXO>, Error>;
    fn del_raw_tx(&mut self, txid: &Txid) -> Result<Option<Transaction>, Error>;
    fn del_tx(
        &mut self,
        txid: &Txid,
        include_raw: bool,
    ) -> Result<Option<TransactionDetails>, Error>;
    fn del_last_index(&mut self, script_type: ScriptType) -> Result<Option<u32>, Error>;
}

pub trait Database: BatchOperations {
    fn check_descriptor_checksum<B: AsRef<[u8]>>(
        &mut self,
        script_type: ScriptType,
        bytes: B,
    ) -> Result<(), Error>;

    fn iter_script_pubkeys(&self, script_type: Option<ScriptType>) -> Result<Vec<Script>, Error>;
    fn iter_utxos(&self) -> Result<Vec<UTXO>, Error>;
    fn iter_raw_txs(&self) -> Result<Vec<Transaction>, Error>;
    fn iter_txs(&self, include_raw: bool) -> Result<Vec<TransactionDetails>, Error>;

    fn get_script_pubkey_from_path(
        &self,
        script_type: ScriptType,
        child: u32,
    ) -> Result<Option<Script>, Error>;
    fn get_path_from_script_pubkey(
        &self,
        script: &Script,
    ) -> Result<Option<(ScriptType, u32)>, Error>;
    fn get_utxo(&self, outpoint: &OutPoint) -> Result<Option<UTXO>, Error>;
    fn get_raw_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error>;
    fn get_tx(&self, txid: &Txid, include_raw: bool) -> Result<Option<TransactionDetails>, Error>;
    fn get_last_index(&self, script_type: ScriptType) -> Result<Option<u32>, Error>;

    // inserts 0 if not present
    fn increment_last_index(&mut self, script_type: ScriptType) -> Result<u32, Error>;
}

pub trait BatchDatabase: Database {
    type Batch: BatchOperations;

    fn begin_batch(&self) -> Self::Batch;
    fn commit_batch(&mut self, batch: Self::Batch) -> Result<(), Error>;
}

pub trait DatabaseUtils: Database {
    fn is_mine(&self, script: &Script) -> Result<bool, Error> {
        self.get_path_from_script_pubkey(script)
            .map(|o| o.is_some())
    }

    fn get_raw_tx_or<F>(&self, txid: &Txid, f: F) -> Result<Option<Transaction>, Error>
    where
        F: FnOnce() -> Result<Option<Transaction>, Error>,
    {
        self.get_tx(txid, true)?
            .map(|t| t.transaction)
            .flatten()
            .map_or_else(f, |t| Ok(Some(t)))
    }

    fn get_previous_output(&self, outpoint: &OutPoint) -> Result<Option<TxOut>, Error> {
        self.get_raw_tx(&outpoint.txid)?
            .and_then(|previous_tx| {
                if outpoint.vout as usize >= previous_tx.output.len() {
                    Some(Err(Error::InvalidOutpoint(outpoint.clone())))
                } else {
                    Some(Ok(previous_tx.output[outpoint.vout as usize].clone()))
                }
            })
            .transpose()
    }
}

impl<T: Database> DatabaseUtils for T {}