//! # dukascopy-fx
//!
//! A production-ready Rust library for fetching historical forex exchange rates,
//! inspired by Python's yfinance library.
//!
//! ## Quick Start
//!
//! ```no_run
//! use dukascopy_fx::{Ticker, datetime};
//!
//! # async fn example() -> dukascopy_fx::Result<()> {
//! // Create a ticker and get data - yfinance style!
//! let ticker = Ticker::new("EUR", "USD");
//!
//! // Get recent rate
//! let rate = ticker.rate().await?;
//! println!("EUR/USD: {}", rate.rate);
//!
//! // Get last week of data
//! let history = ticker.history("1w").await?;
//! for r in history {
//!     println!("{}: {}", r.timestamp, r.rate);
//! }
//! # Ok(())
//! # }
//! ```
//!
//! ## Features
//!
//! - **yfinance-style API**: Familiar `Ticker` object with `history()` method
//! - **Period strings**: Use `"1d"`, `"1w"`, `"1mo"`, `"1y"` for easy time ranges
//! - **Built-in time utilities**: No need to add chrono separately
//! - **Type-safe**: Strong types for currency pairs, rates, and errors
//! - **Automatic handling**: JPY pairs, metals, weekends - all transparent
//!
//! ## Usage Patterns
//!
//! ### Ticker API (Recommended)
//! ```no_run
//! use dukascopy_fx::{Ticker, datetime};
//!
//! # async fn example() -> dukascopy_fx::Result<()> {
//! let eur_usd = Ticker::new("EUR", "USD");
//! let gold = Ticker::xau_usd();
//!
//! // Get rate at specific time
//! let rate = eur_usd.rate_at(datetime!(2024-01-15 14:30 UTC)).await?;
//!
//! // Get historical data with period strings
//! let weekly = eur_usd.history("1w").await?;
//! # Ok(())
//! # }
//! ```
//!
//! ### Batch Download
//! ```no_run
//! use dukascopy_fx::{Ticker, download};
//!
//! # async fn example() -> dukascopy_fx::Result<()> {
//! let tickers = vec![
//!     Ticker::eur_usd(),
//!     Ticker::gbp_usd(),
//!     Ticker::usd_jpy(),
//! ];
//!
//! let data = download(&tickers, "1w").await?;
//! for (ticker, rates) in data {
//!     println!("{}: {} records", ticker.symbol(), rates.len());
//! }
//! # Ok(())
//! # }
//! ```
//!
//! ### Simple Function API
//! ```no_run
//! use dukascopy_fx::{get_rate, datetime};
//!
//! # async fn example() -> dukascopy_fx::Result<()> {
//! let rate = get_rate("EUR", "USD", datetime!(2024-01-15 14:30 UTC)).await?;
//! println!("Rate: {}", rate.rate);
//! # Ok(())
//! # }
//! ```

// ============================================================================
// Internal modules
// ============================================================================

mod api;
pub(crate) mod core;

// ============================================================================
// Public modules
// ============================================================================

pub mod error;
pub mod interop;
pub mod macros;
pub mod market;
pub mod models;
pub mod storage;
pub mod time;

// ============================================================================
// Core exports
// ============================================================================

pub use api::{
    download, download_incremental, download_incremental_with_client,
    download_incremental_with_concurrency, download_range, download_range_with_client,
    download_range_with_concurrency, download_with_client, download_with_concurrency, Period,
    Ticker, DEFAULT_DOWNLOAD_CONCURRENCY,
};
pub use core::catalog::{AssetClass, InstrumentCatalog, InstrumentDefinition};
pub use error::DukascopyError;
pub use interop::{flatten_row, flatten_rows, FlatExchangeRow};
pub use models::{CurrencyExchange, CurrencyPair, RateRequest, RequestParseMode};
pub use storage::checkpoint::{CheckpointStore, FileCheckpointStore};
#[cfg(feature = "sinks-parquet")]
pub use storage::sink::ParquetSink;
pub use storage::sink::{CsvSink, DataSink, NoopSink};

/// Convenient alias for [`DukascopyError`]
pub type Error = DukascopyError;

/// Convenient Result type for this crate
pub type Result<T> = std::result::Result<T, Error>;

// ============================================================================
// Simple Function API
// ============================================================================

use chrono::{DateTime, Duration, Utc};

/// Fetches the exchange rate for a currency pair at a specific timestamp.
#[inline]
pub async fn get_rate(from: &str, to: &str, timestamp: DateTime<Utc>) -> Result<CurrencyExchange> {
    let pair = CurrencyPair::try_new(from, to)?;
    core::client::DukascopyClient::get_exchange_rate(&pair, timestamp).await
}

/// Fetches exchange rate for a unified request type (pair or symbol).
#[inline]
pub async fn get_rate_for_request(
    request: &RateRequest,
    timestamp: DateTime<Utc>,
) -> Result<CurrencyExchange> {
    core::client::DukascopyClient::get_exchange_rate_for_request(request, timestamp).await
}

/// Parses request from input and fetches exchange rate.
///
/// Parsing rules:
/// - input containing `/` is parsed as pair (e.g. `EUR/USD`)
/// - 6-letter FX shorthand (e.g. `EURUSD`, `XAUUSD`) is parsed as pair
/// - otherwise input is parsed as symbol (e.g. `AAPL`, `USA500IDX`)
#[inline]
pub async fn get_rate_for_input(input: &str, timestamp: DateTime<Utc>) -> Result<CurrencyExchange> {
    let request: RateRequest = input.parse()?;
    get_rate_for_request(&request, timestamp).await
}

/// Parses request from input using explicit parse mode and fetches exchange rate.
#[inline]
pub async fn get_rate_for_input_with_mode(
    input: &str,
    mode: RequestParseMode,
    timestamp: DateTime<Utc>,
) -> Result<CurrencyExchange> {
    let request = RateRequest::parse_with_mode(input, mode)?;
    get_rate_for_request(&request, timestamp).await
}

/// Fetches the exchange rate using a [`CurrencyPair`].
#[inline]
pub async fn get_rate_for_pair(
    pair: &CurrencyPair,
    timestamp: DateTime<Utc>,
) -> Result<CurrencyExchange> {
    core::client::DukascopyClient::get_exchange_rate(pair, timestamp).await
}

/// Fetches exchange rates over a time range.
#[inline]
pub async fn get_rates_range(
    from: &str,
    to: &str,
    start: DateTime<Utc>,
    end: DateTime<Utc>,
    interval: Duration,
) -> Result<Vec<CurrencyExchange>> {
    let pair = CurrencyPair::try_new(from, to)?;
    core::client::DukascopyClient::get_exchange_rates_range(&pair, start, end, interval).await
}

/// Fetches exchange rates over a time range using a [`CurrencyPair`].
#[inline]
pub async fn get_rates_range_for_pair(
    pair: &CurrencyPair,
    start: DateTime<Utc>,
    end: DateTime<Utc>,
    interval: Duration,
) -> Result<Vec<CurrencyExchange>> {
    core::client::DukascopyClient::get_exchange_rates_range(pair, start, end, interval).await
}

/// Fetches exchange rate for a symbol using global client default quote currency.
#[inline]
pub async fn get_rate_for_symbol(
    symbol: &str,
    timestamp: DateTime<Utc>,
) -> Result<CurrencyExchange> {
    core::client::DukascopyClient::get_exchange_rate_for_symbol(symbol, timestamp).await
}

/// Fetches exchange rate for a symbol in target quote currency.
#[inline]
pub async fn get_rate_in_quote(
    symbol: &str,
    quote: &str,
    timestamp: DateTime<Utc>,
) -> Result<CurrencyExchange> {
    core::client::DukascopyClient::get_exchange_rate_in_quote(symbol, quote, timestamp).await
}

// ============================================================================
// Market hours API
// ============================================================================

pub use market::{get_market_status, is_market_open, is_weekend, MarketStatus};

// ============================================================================
// Advanced API module
// ============================================================================

/// Advanced API for power users who need fine-grained control.
///
/// This module exposes internal types for:
/// - Custom client configuration (cache size, timeouts)
/// - Custom instrument configurations (for new/exotic instruments)
/// - Low-level parsing utilities
///
/// # Example
/// ```no_run
/// use dukascopy_fx::advanced::{DukascopyClientBuilder, InstrumentConfig};
///
/// let client = DukascopyClientBuilder::new()
///     .cache_size(500)
///     .timeout_secs(60)
///     .with_instrument_config("BTC", "USD", InstrumentConfig::new(100.0, 2))
///     .build();
/// ```
pub mod advanced {
    pub use crate::core::catalog::{AssetClass, InstrumentCatalog, InstrumentDefinition};
    pub use crate::core::client::{
        ClientConfig, ConfiguredClient, ConversionMode, ConversionPathType, DukascopyClient,
        DukascopyClientBuilder, PairResolutionMode, ResolvedExchange, DEFAULT_CACHE_SIZE,
        DEFAULT_MAX_AT_OR_BEFORE_BACKTRACK_HOURS, DEFAULT_MAX_DOWNLOAD_CONCURRENCY,
        DEFAULT_MAX_IDLE_CONNECTIONS, DEFAULT_MAX_IN_FLIGHT_REQUESTS, DEFAULT_MAX_RETRIES,
        DEFAULT_RETRY_BASE_DELAY_MS, DEFAULT_TIMEOUT_SECS, DUKASCOPY_BASE_URL,
        GLOBAL_DEFAULT_QUOTE_CURRENCY,
    };
    pub use crate::core::instrument::{
        resolve_instrument_config, CurrencyCategory, DefaultInstrumentProvider,
        HasInstrumentConfig, InstrumentConfig, InstrumentProvider, OverrideInstrumentProvider,
        DIVISOR_2_DECIMALS, DIVISOR_3_DECIMALS, DIVISOR_5_DECIMALS,
    };
    pub use crate::core::parser::{DukascopyParser, ParsedTick, TICK_SIZE_BYTES};
    pub use crate::market::last_available_tick_time;
    pub use crate::models::{RateRequest, RequestParseMode};
    pub use crate::storage::checkpoint::{CheckpointStore, FileCheckpointStore};
    #[cfg(feature = "sinks-parquet")]
    pub use crate::storage::sink::ParquetSink;
    pub use crate::storage::sink::{CsvSink, DataSink, NoopSink};
}

// ============================================================================
// Prelude module
// ============================================================================

/// Prelude module - import everything commonly needed.
///
/// ```
/// use dukascopy_fx::prelude::*;
/// ```
pub mod prelude {
    pub use crate::api::{
        download, download_incremental, download_incremental_with_client,
        download_incremental_with_concurrency, download_range, download_range_with_client,
        download_range_with_concurrency, download_with_client, download_with_concurrency, Period,
        Ticker, DEFAULT_DOWNLOAD_CONCURRENCY,
    };
    pub use crate::core::catalog::{AssetClass, InstrumentCatalog, InstrumentDefinition};
    pub use crate::error::DukascopyError;
    pub use crate::market::{is_market_open, is_weekend, MarketStatus};
    pub use crate::models::{CurrencyExchange, CurrencyPair, RateRequest, RequestParseMode};
    pub use crate::storage::checkpoint::{CheckpointStore, FileCheckpointStore};
    #[cfg(feature = "sinks-parquet")]
    pub use crate::storage::sink::ParquetSink;
    pub use crate::storage::sink::{CsvSink, DataSink, NoopSink};
    pub use crate::time::{
        date, datetime, days_ago, hours_ago, now, try_datetime_utc, weeks_ago, DateTime, Duration,
        Utc,
    };
    pub use crate::{datetime, ticker, try_datetime, try_ticker};
    pub use crate::{
        get_rate, get_rate_for_input, get_rate_for_input_with_mode, get_rate_for_pair,
        get_rate_for_request, get_rate_for_symbol, get_rate_in_quote, get_rates_range,
        get_rates_range_for_pair,
    };
    pub use crate::{Error, Result};
}

#[cfg(test)]
mod tests {
    use super::*;
    use chrono::Utc;

    #[tokio::test]
    async fn test_get_rate_for_input_rejects_empty_request() {
        let err = get_rate_for_input("   ", Utc::now()).await.unwrap_err();
        assert!(matches!(err, DukascopyError::InvalidRequest(_)));
    }

    #[tokio::test]
    async fn test_get_rate_for_input_rejects_invalid_symbol() {
        let err = get_rate_for_input("BAD$", Utc::now()).await.unwrap_err();
        assert!(matches!(
            err,
            DukascopyError::InvalidCurrencyCode { code, .. } if code == "BAD$"
        ));
    }

    #[tokio::test]
    async fn test_get_rate_for_input_rejects_invalid_pair() {
        let err = get_rate_for_input("EUR/US$", Utc::now()).await.unwrap_err();
        assert!(matches!(
            err,
            DukascopyError::InvalidCurrencyCode { code, .. } if code == "US$"
        ));
    }

    #[tokio::test]
    async fn test_get_rate_for_request_rejects_invalid_pair_before_network() {
        let request = RateRequest::pair("BAD$", "USD");
        let err = get_rate_for_request(&request, Utc::now())
            .await
            .unwrap_err();
        assert!(matches!(
            err,
            DukascopyError::InvalidCurrencyCode { code, .. } if code == "BAD$"
        ));
    }

    #[tokio::test]
    async fn test_get_rate_for_request_rejects_invalid_symbol_before_network() {
        let request = RateRequest::Symbol("BAD$".to_string());
        let err = get_rate_for_request(&request, Utc::now())
            .await
            .unwrap_err();
        assert!(matches!(
            err,
            DukascopyError::InvalidCurrencyCode { code, .. } if code == "BAD$"
        ));
    }
}
