// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use super::{
    compact_options::{CompactCurrencyFormatterOptions, Width},
    CurrencyCode,
};
use crate::{
    compactdecimal::CompactDecimalFormatter,
    dimension::provider::{
        currency::{self, CurrencyEssentialsV1},
        currency_compact::ShortCurrencyCompactV1,
    },
};
use fixed_decimal::SignedFixedDecimal;
use writeable::Writeable;

pub struct FormattedCompactCurrency<'l> {
    pub(crate) value: &'l SignedFixedDecimal,
    pub(crate) currency_code: CurrencyCode,
    pub(crate) options: &'l CompactCurrencyFormatterOptions,
    pub(crate) essential: &'l CurrencyEssentialsV1<'l>,
    pub(crate) _short_currency_compact: &'l ShortCurrencyCompactV1<'l>,
    pub(crate) compact_decimal_formatter: &'l CompactDecimalFormatter,
}

writeable::impl_display_with_writeable!(FormattedCompactCurrency<'_>);

impl<'l> Writeable for FormattedCompactCurrency<'l> {
    fn write_to<W>(&self, sink: &mut W) -> core::result::Result<(), core::fmt::Error>
    where
        W: core::fmt::Write + ?Sized,
    {
        let config = self
            .essential
            .pattern_config_map
            .get_copied(&self.currency_code.0.to_unvalidated())
            .unwrap_or(self.essential.default_pattern_config);

        let placeholder_index = match self.options.width {
            Width::Short => config.short_placeholder_value,
            Width::Narrow => config.narrow_placeholder_value,
        };

        let currency_placeholder = match placeholder_index {
            Some(currency::PlaceholderValue::Index(index)) => self
                .essential
                .placeholders
                .get(index.into())
                .ok_or(core::fmt::Error)?,
            Some(currency::PlaceholderValue::ISO) | None => self.currency_code.0.as_str(),
        };

        let pattern_selection = match self.options.width {
            Width::Short => config.short_pattern_selection,
            Width::Narrow => config.narrow_pattern_selection,
        };

        // TODO: The current behavior is the behavior when there is no compact currency pattern found.
        // Therefore, in the next PR, we will add the code to handle using the compact currency patterns.

        let pattern = match pattern_selection {
            currency::PatternSelection::Standard => self.essential.standard_pattern.as_ref(),
            currency::PatternSelection::StandardAlphaNextToNumber => self
                .essential
                .standard_alpha_next_to_number_pattern
                .as_ref(),
        }
        .ok_or(core::fmt::Error)?;

        pattern
            .interpolate((
                self.compact_decimal_formatter
                    .format_fixed_decimal(self.value),
                currency_placeholder,
            ))
            .write_to(sink)?;

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use icu_locale_core::locale;
    use tinystr::*;
    use writeable::assert_writeable_eq;

    use crate::dimension::currency::{compact_formatter::CompactCurrencyFormatter, CurrencyCode};

    #[test]
    pub fn test_en_us() {
        let locale = locale!("en-US").into();
        let currency_code = CurrencyCode(tinystr!(3, "USD"));
        let fmt = CompactCurrencyFormatter::try_new(locale, Default::default()).unwrap();

        // Positive case
        let positive_value = "12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&positive_value, currency_code);
        assert_writeable_eq!(formatted_currency, "$12K");

        // Negative case
        let negative_value = "-12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&negative_value, currency_code);
        assert_writeable_eq!(formatted_currency, "$-12K");
    }

    #[test]
    pub fn test_fr_fr() {
        let locale = locale!("fr-FR").into();
        let currency_code = CurrencyCode(tinystr!(3, "EUR"));
        let fmt = CompactCurrencyFormatter::try_new(locale, Default::default()).unwrap();

        // Positive case
        let positive_value = "12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&positive_value, currency_code);
        assert_writeable_eq!(formatted_currency, "12\u{a0}k\u{a0}€");

        // Negative case
        let negative_value = "-12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&negative_value, currency_code);
        assert_writeable_eq!(formatted_currency, "-12\u{a0}k\u{a0}€");
    }

    #[test]
    pub fn test_zh_cn() {
        let locale = locale!("zh-CN").into();
        let currency_code = CurrencyCode(tinystr!(3, "CNY"));
        let fmt = CompactCurrencyFormatter::try_new(locale, Default::default()).unwrap();

        // Positive case
        let positive_value = "12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&positive_value, currency_code);
        assert_writeable_eq!(formatted_currency, "¥1.2万");

        // Negative case
        let negative_value = "-12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&negative_value, currency_code);
        assert_writeable_eq!(formatted_currency, "¥-1.2万");
    }

    #[test]
    pub fn test_ar_eg() {
        let locale = locale!("ar-EG").into();
        let currency_code = CurrencyCode(tinystr!(3, "EGP"));
        let fmt = CompactCurrencyFormatter::try_new(locale, Default::default()).unwrap();

        // Positive case
        let positive_value = "12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&positive_value, currency_code);
        assert_writeable_eq!(formatted_currency, "\u{200f}١٢\u{a0}ألف\u{a0}ج.م.\u{200f}"); //  "١٢ ألف ج.م."

        // Negative case
        let negative_value = "-12345.67".parse().unwrap();
        let formatted_currency = fmt.format_fixed_decimal(&negative_value, currency_code);
        assert_writeable_eq!(
            formatted_currency,
            "\u{200f}\u{61c}-١٢\u{a0}ألف\u{a0}ج.م.\u{200f}"
        );
    }
}