use crate::presentation::order::Status;
use pretty_simple_display::{DebugPretty, DisplaySimple};
use regex::Regex;
use serde::{Deserialize, Deserializer, Serialize};
use tracing::warn;

/// Structure to represent the parsed option information from an instrument name
#[derive(DebugPretty, DisplaySimple, Clone, Serialize, Deserialize, PartialEq)]
pub struct ParsedOptionInfo {
    /// Name of the underlying asset (e.g., "US Tech 100")
    pub asset_name: String,
    /// Strike price of the option (e.g., "19200")
    pub strike: Option<String>,
    /// Type of the option: CALL or PUT
    pub option_type: Option<String>,
}

/// Structure to represent the parsed market data with additional information
#[derive(DebugPretty, DisplaySimple, Clone, Serialize, Deserialize)]
pub struct ParsedMarketData {
    /// Unique identifier for the market (EPIC code)
    pub epic: String,
    /// Full name of the financial instrument
    pub instrument_name: String,
    /// Expiry date of the instrument (if applicable)
    pub expiry: String,
    /// Name of the underlying asset
    pub asset_name: String,
    /// Strike price for options
    pub strike: Option<String>,
    /// Type of option (e.g., 'CALL' or 'PUT')
    pub option_type: Option<String>,
}

impl ParsedMarketData {
    /// Checks if the current financial instrument is a call option.
    ///
    /// A call option is a financial derivative that gives the holder the right (but not the obligation)
    /// to buy an underlying asset at a specified price within a specified time period. This method checks
    /// whether the instrument is a call option by inspecting the already-parsed `option_type` field.
    ///
    /// # Returns
    ///
    /// * `true` if the parsed `option_type` is exactly `"CALL"`, indicating it is a call option.
    /// * `false` otherwise.
    ///
    #[must_use]
    #[inline]
    pub fn is_call(&self) -> bool {
        self.option_type.as_deref() == Some("CALL")
    }

    /// Checks if the financial instrument is a "PUT" option.
    ///
    /// This method inspects the already-parsed `option_type` field rather than
    /// re-scanning the instrument name, so it stays in sync with the parser.
    ///
    /// # Returns
    /// * `true` - If the parsed `option_type` is exactly `"PUT"`.
    /// * `false` - Otherwise.
    ///
    #[must_use]
    #[inline]
    pub fn is_put(&self) -> bool {
        self.option_type.as_deref() == Some("PUT")
    }
}

/// Normalize text by removing accents and standardizing names
///
/// This function converts accented characters to their non-accented equivalents
/// and standardizes certain names (e.g., "Japan" in different languages)
pub fn normalize_text(text: &str) -> String {
    // Special case for Japan in Spanish
    if text.contains("Japón") {
        return text.replace("Japón", "Japan");
    }

    let mut result = String::with_capacity(text.len());
    for c in text.chars() {
        match c {
            'á' | 'à' | 'ä' | 'â' | 'ã' => result.push('a'),
            'é' | 'è' | 'ë' | 'ê' => result.push('e'),
            'í' | 'ì' | 'ï' | 'î' => result.push('i'),
            'ó' | 'ò' | 'ö' | 'ô' | 'õ' => result.push('o'),
            'ú' | 'ù' | 'ü' | 'û' => result.push('u'),
            'ñ' => result.push('n'),
            'ç' => result.push('c'),
            'Á' | 'À' | 'Ä' | 'Â' | 'Ã' => result.push('A'),
            'É' | 'È' | 'Ë' | 'Ê' => result.push('E'),
            'Í' | 'Ì' | 'Ï' | 'Î' => result.push('I'),
            'Ó' | 'Ò' | 'Ö' | 'Ô' | 'Õ' => result.push('O'),
            'Ú' | 'Ù' | 'Ü' | 'Û' => result.push('U'),
            'Ñ' => result.push('N'),
            'Ç' => result.push('C'),
            _ => result.push(c),
        }
    }
    result
}

/// Parse the instrument name to extract asset name, strike price, and option type
///
/// # Examples
///
/// ```
/// use ig_client::utils::parsing::parse_instrument_name;
///
/// let info = parse_instrument_name("US Tech 100 19200 CALL ($1)");
/// assert_eq!(info.asset_name, "US Tech 100");
/// assert_eq!(info.strike, Some("19200".to_string()));
/// assert_eq!(info.option_type, Some("CALL".to_string()));
///
/// let info = parse_instrument_name("Germany 40");
/// assert_eq!(info.asset_name, "Germany 40");
/// assert_eq!(info.strike, None);
/// assert_eq!(info.option_type, None);
/// ```
pub fn parse_instrument_name(instrument_name: &str) -> ParsedOptionInfo {
    // Create regex patterns for different instrument name formats
    // Lazy initialization of regex patterns
    lazy_static::lazy_static! {
        // Pattern for standard options like "US Tech 100 19200 CALL ($1)".
        // The strike group accepts an optional decimal part, so this pattern
        // already covers decimal strikes like "Volatility Index 10.5 PUT ($1)".
        static ref OPTION_PATTERN: Regex = Regex::new(r"^(.*?)\s+(\d+(?:\.\d+)?)\s+(CALL|PUT)(?:\s+\(.*?\))?$").expect("valid option regex");

        // Pattern for options with no space between parenthesis and strike like "Weekly Germany 40 (Wed)27500 PUT"
        static ref SPECIAL_OPTION_PATTERN: Regex = Regex::new(r"^(.*?)\s+\(([^)]+)\)(\d+)\s+(CALL|PUT)(?:\s+\(.*?\))?$").expect("valid special option regex");

        // Pattern for options with incomplete parenthesis like "Weekly USDJPY 12950 CALL (Y100"
        static ref INCOMPLETE_PAREN_PATTERN: Regex = Regex::new(r"^(.*?)\s+(\d+(?:\.\d+)?)\s+(CALL|PUT)\s+\([^)]*$").expect("valid incomplete paren regex");

        // Pattern for other instruments that don't follow the option pattern
        static ref GENERIC_PATTERN: Regex = Regex::new(r"^(.*?)(?:\s+\(.*?\))?$").expect("valid generic regex");

        // Pattern to clean up asset names
        static ref DAILY_WEEKLY_PATTERN: Regex = Regex::new(r"^(Daily|Weekly)\s+(.*?)$").expect("valid daily/weekly regex");
        static ref END_OF_MONTH_PATTERN: Regex = Regex::new(r"^(End of Month)\s+(.*?)$").expect("valid end-of-month regex");
        static ref QUARTERLY_PATTERN: Regex = Regex::new(r"^(Quarterly)\s+(.*?)$").expect("valid quarterly regex");
        static ref MONTHLY_PATTERN: Regex = Regex::new(r"^(Monthly)\s+(.*?)$").expect("valid monthly regex");
        static ref SUFFIX_PATTERN: Regex = Regex::new(r"^(.*?)\s+\(.*?\)$").expect("valid suffix regex");
    }

    // Helper function to clean up asset names
    fn clean_asset_name(asset_name: &str) -> String {
        // First normalize the text to remove accents
        let normalized_name = normalize_text(asset_name);

        // Remove prefixes like "Daily", "Weekly", etc.
        let asset_name = if let Some(captures) = DAILY_WEEKLY_PATTERN.captures(&normalized_name) {
            captures.get(2).map_or("", |m| m.as_str()).trim()
        } else if let Some(captures) = END_OF_MONTH_PATTERN.captures(&normalized_name) {
            captures.get(2).map_or("", |m| m.as_str()).trim()
        } else if let Some(captures) = QUARTERLY_PATTERN.captures(&normalized_name) {
            captures.get(2).map_or("", |m| m.as_str()).trim()
        } else if let Some(captures) = MONTHLY_PATTERN.captures(&normalized_name) {
            captures.get(2).map_or("", |m| m.as_str()).trim()
        } else {
            &normalized_name
        };

        // Remove suffixes like "(End of Month)", etc.
        let asset_name = if let Some(captures) = SUFFIX_PATTERN.captures(asset_name) {
            captures.get(1).map_or("", |m| m.as_str()).trim()
        } else {
            asset_name
        };

        asset_name.to_string()
    }

    if let Some(captures) = OPTION_PATTERN.captures(instrument_name) {
        // This is an option with strike and type
        let asset_name = captures.get(1).map_or("", |m| m.as_str()).trim();
        ParsedOptionInfo {
            asset_name: clean_asset_name(asset_name),
            strike: captures.get(2).map(|m| m.as_str().to_string()),
            option_type: captures.get(3).map(|m| m.as_str().to_string()),
        }
    } else if let Some(captures) = SPECIAL_OPTION_PATTERN.captures(instrument_name) {
        // This is a special case like "Weekly Germany 40 (Wed)27500 PUT"
        let base_name = captures.get(1).map_or("", |m| m.as_str()).trim();
        ParsedOptionInfo {
            asset_name: clean_asset_name(base_name),
            strike: captures.get(3).map(|m| m.as_str().to_string()),
            option_type: captures.get(4).map(|m| m.as_str().to_string()),
        }
    } else if let Some(captures) = INCOMPLETE_PAREN_PATTERN.captures(instrument_name) {
        // This is a case with incomplete parenthesis like "Weekly USDJPY 12950 CALL (Y100"
        let asset_name = captures.get(1).map_or("", |m| m.as_str()).trim();
        ParsedOptionInfo {
            asset_name: clean_asset_name(asset_name),
            strike: captures.get(2).map(|m| m.as_str().to_string()),
            option_type: captures.get(3).map(|m| m.as_str().to_string()),
        }
    } else if let Some(captures) = GENERIC_PATTERN.captures(instrument_name) {
        // This is a generic instrument without strike or type
        let asset_name = captures.get(1).map_or("", |m| m.as_str()).trim();
        ParsedOptionInfo {
            asset_name: clean_asset_name(asset_name),
            strike: None,
            option_type: None,
        }
    } else {
        // Fallback for any other format
        warn!("Could not parse instrument name: {}", instrument_name);
        ParsedOptionInfo {
            asset_name: instrument_name.to_string(),
            strike: None,
            option_type: None,
        }
    }
}

/// Helper function to deserialize null values as empty vectors
pub fn deserialize_null_as_empty_vec<'de, D, T>(deserializer: D) -> Result<Vec<T>, D::Error>
where
    D: serde::Deserializer<'de>,
    T: serde::Deserialize<'de>,
{
    let opt = Option::deserialize(deserializer)?;
    Ok(opt.unwrap_or_default())
}

/// Helper function to deserialize a nullable status field
/// When the status is null in the JSON, we default to Open status
pub fn deserialize_nullable_status<'de, D>(deserializer: D) -> Result<Status, D::Error>
where
    D: Deserializer<'de>,
{
    let opt = Option::deserialize(deserializer)?;
    Ok(opt.unwrap_or(Status::Open))
}

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

    #[test]
    fn test_parse_instrument_name_standard_option() {
        let info = parse_instrument_name("US Tech 100 19200 CALL ($1)");
        assert_eq!(info.asset_name, "US Tech 100");
        assert_eq!(info.strike, Some("19200".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_decimal_strike() {
        // Proves `OPTION_PATTERN` alone handles decimal strikes; there is no
        // separate decimal-strike pattern.
        let info = parse_instrument_name("Volatility Index 10.5 PUT ($1)");
        assert_eq!(info.asset_name, "Volatility Index");
        assert_eq!(info.strike, Some("10.5".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_decimal_strike_no_suffix() {
        // A decimal strike without a trailing "($1)" suffix is still handled by
        // `OPTION_PATTERN`.
        let info = parse_instrument_name("Volatility Index 10.5 CALL");
        assert_eq!(info.asset_name, "Volatility Index");
        assert_eq!(info.strike, Some("10.5".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_no_option() {
        let info = parse_instrument_name("Germany 40");
        assert_eq!(info.asset_name, "Germany 40");
        assert_eq!(info.strike, None);
        assert_eq!(info.option_type, None);
    }

    fn market_with_option_type(option_type: Option<&str>) -> ParsedMarketData {
        ParsedMarketData {
            epic: "OP.D.OTCSPX3.6910C.IP".to_string(),
            instrument_name: "US 500 6910 CALL ($1)".to_string(),
            expiry: "DEC-25".to_string(),
            asset_name: "US 500".to_string(),
            strike: Some("6910".to_string()),
            option_type: option_type.map(str::to_string),
        }
    }

    #[test]
    fn test_parsed_market_data_is_call_uses_parsed_option_type() {
        let call = market_with_option_type(Some("CALL"));
        assert!(call.is_call());
        assert!(!call.is_put());
    }

    #[test]
    fn test_parsed_market_data_is_put_uses_parsed_option_type() {
        let put = market_with_option_type(Some("PUT"));
        assert!(put.is_put());
        assert!(!put.is_call());
    }

    #[test]
    fn test_parsed_market_data_no_option_type_is_neither() {
        // A non-option instrument has `option_type == None`, so neither
        // predicate fires even though the name might contain other tokens.
        let none = market_with_option_type(None);
        assert!(!none.is_call());
        assert!(!none.is_put());
    }

    #[test]
    fn test_parse_instrument_name_with_parenthesis() {
        let info = parse_instrument_name("US 500 (Mini)");
        assert_eq!(info.asset_name, "US 500");
        assert_eq!(info.strike, None);
        assert_eq!(info.option_type, None);
    }

    #[test]
    fn test_parse_instrument_name_special_format() {
        let info = parse_instrument_name("Weekly Germany 40 (Wed)27500 PUT");
        assert_eq!(info.asset_name, "Germany 40");
        assert_eq!(info.strike, Some("27500".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_daily_prefix() {
        let info = parse_instrument_name("Daily Germany 40 24225 CALL");
        assert_eq!(info.asset_name, "Germany 40");
        assert_eq!(info.strike, Some("24225".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_weekly_prefix() {
        let info = parse_instrument_name("Weekly US Tech 100 19200 CALL");
        assert_eq!(info.asset_name, "US Tech 100");
        assert_eq!(info.strike, Some("19200".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_end_of_month_prefix() {
        let info = parse_instrument_name("End of Month EU Stocks 50 4575 PUT");
        assert_eq!(info.asset_name, "EU Stocks 50");
        assert_eq!(info.strike, Some("4575".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_end_of_month_suffix() {
        let info = parse_instrument_name("US 500 (End of Month) 3200 PUT");
        assert_eq!(info.asset_name, "US 500");
        assert_eq!(info.strike, Some("3200".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_quarterly_prefix() {
        let info = parse_instrument_name("Quarterly GBPUSD 10000 PUT ($1)");
        assert_eq!(info.asset_name, "GBPUSD");
        assert_eq!(info.strike, Some("10000".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_weekly_with_day() {
        let info = parse_instrument_name("Weekly Germany 40 (Mon) 18500 PUT");
        assert_eq!(info.asset_name, "Germany 40");
        assert_eq!(info.strike, Some("18500".to_string()));
        assert_eq!(info.option_type, Some("PUT".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_incomplete_parenthesis() {
        let info = parse_instrument_name("Weekly USDJPY 12950 CALL (Y100");
        assert_eq!(info.asset_name, "USDJPY");
        assert_eq!(info.strike, Some("12950".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }

    #[test]
    fn test_parse_instrument_name_with_accents() {
        let info = parse_instrument_name("Japón 225 18500 CALL");
        assert_eq!(info.asset_name, "Japan 225");
        assert_eq!(info.strike, Some("18500".to_string()));
        assert_eq!(info.option_type, Some("CALL".to_string()));
    }
}
