use anyhow::Result;
use serde::{Deserialize, Serialize};

/// Use integer incase we switch to i128 or otherwise.
pub type Integer = i64;

/// Non negative integer including 0
pub type Natural = u64;

/// Suggestive of a positive integer. Note that this is not enforced at a type level.
pub type Positive = u64;

/// A natural representing and `amount of currency`
pub type Amount = Natural;

/// A natural representing an index of, say, a cheque or utxo.
pub type Index = Natural;

/// A time length in milliseconds
pub type Milliseconds = Integer;

/// Milliseconds since Epoch
pub type Timestamp = Natural;

// Alias for bytes
pub type Blake2b256Hash = [u8; 32];
pub type Blake2b224Hash = [u8; 28];
pub type KeyHash = Blake2b224Hash;
pub type ScriptHash = Blake2b224Hash;
pub type TransactionId = Blake2b256Hash;
pub type AssetName = Vec<u8>;
pub type VerificationKey = [u8; 32];
pub type Signature = [u8; 64];
pub type ChannelId = [u8; 28];

pub type Currency = (ScriptHash, AssetName);

/// To keep types consistent we denote the script hash of ada as `[0;28]`.
pub fn ada_currency() -> Currency {
    ([0; 28], [0_u8; 0].to_vec())
}

pub type Markdown = String;
pub type Text = String;

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct Signed<T> {
    body: T,
    #[serde(with = "serde_arrays")]
    signature: [u8; 64],
}

pub const E3: Natural = 1000 as Natural;
pub const E6: Natural = E3 * E3;
pub const E9: Natural = E6 * E3;
pub const E12: Natural = E9 * E3;

pub const SECOND: Milliseconds = 1000;
pub const MINUTE: Milliseconds = 60 * SECOND;
pub const HOUR: Milliseconds = 60 * MINUTE;
pub const DAY: Milliseconds = 24 * HOUR;

pub fn time_add(a: Timestamp, b: Milliseconds) -> Result<Timestamp> {
    let x = Timestamp::try_from(a as i64 + b)?;
    Ok(x)
}