use arrow::temporal_conversions::{EPOCH_DAYS_FROM_CE, MILLISECONDS, SECONDS_IN_DAY};
use chrono::{Datelike, NaiveDate};

use super::*;

pub(crate) fn naive_date_to_date(nd: NaiveDate) -> i32 {
    let nt = NaiveTime::from_hms_opt(0, 0, 0).unwrap();
    let ndt = NaiveDateTime::new(nd, nt);
    naive_datetime_to_date(ndt)
}

pub(crate) fn naive_datetime_to_date(v: NaiveDateTime) -> i32 {
    (datetime_to_timestamp_ms(v) / (MILLISECONDS * SECONDS_IN_DAY)) as i32
}

pub trait DateMethods: AsDate {
    /// Extract month from underlying NaiveDate representation.
    /// Returns the year number in the calendar date.
    fn year(&self) -> Int32Chunked {
        let ca = self.as_date();
        ca.physical().apply_kernel_cast::<Int32Type>(&date_to_year)
    }

    /// Extract year from underlying NaiveDate representation.
    /// Returns whether the year is a leap year.
    fn is_leap_year(&self) -> BooleanChunked {
        let ca = self.as_date();
        ca.physical()
            .apply_kernel_cast::<BooleanType>(&date_to_is_leap_year)
    }

    /// This year number might not match the calendar year number.
    fn iso_year(&self) -> Int32Chunked {
        let ca = self.as_date();
        ca.physical()
            .apply_kernel_cast::<Int32Type>(&date_to_iso_year)
    }

    /// Extract month from underlying NaiveDateTime representation.
    /// Quarters range from 1 to 4.
    fn quarter(&self) -> Int8Chunked {
        let months = self.month();
        months_to_quarters(months)
    }

    /// Extract month from underlying NaiveDateTime representation.
    /// Returns the month number starting from 1.
    ///
    /// The return value ranges from 1 to 12.
    fn month(&self) -> Int8Chunked {
        let ca = self.as_date();
        ca.physical().apply_kernel_cast::<Int8Type>(&date_to_month)
    }

    /// Returns the number of days in the month of the underlying NaiveDate
    /// representation.
    fn days_in_month(&self) -> Int8Chunked {
        let ca = self.as_date();
        ca.physical()
            .apply_kernel_cast::<Int8Type>(&date_to_days_in_month)
    }

    /// Returns the ISO week number starting from 1.
    /// The return value ranges from 1 to 53. (The last week of year differs by years.)
    fn week(&self) -> Int8Chunked {
        let ca = self.as_date();
        ca.physical()
            .apply_kernel_cast::<Int8Type>(&date_to_iso_week)
    }

    /// Extract day from underlying NaiveDate representation.
    /// Returns the day of month starting from 1.
    ///
    /// The return value ranges from 1 to 31. (The last day of month differs by months.)
    fn day(&self) -> Int8Chunked {
        let ca = self.as_date();
        ca.physical().apply_kernel_cast::<Int8Type>(&date_to_day)
    }

    /// Returns the day of year starting from 1.
    ///
    /// The return value ranges from 1 to 366. (The last day of year differs by years.)
    fn ordinal(&self) -> Int16Chunked {
        let ca = self.as_date();
        ca.physical()
            .apply_kernel_cast::<Int16Type>(&date_to_ordinal)
    }

    fn parse_from_str_slice(name: PlSmallStr, v: &[&str], fmt: &str) -> DateChunked;

    /// Construct a date ChunkedArray from individual time components.
    fn new_from_parts(
        year: &Int32Chunked,
        month: &Int8Chunked,
        day: &Int8Chunked,
        name: PlSmallStr,
    ) -> PolarsResult<DateChunked> {
        let ca: Int32Chunked = year
            .into_iter()
            .zip(month)
            .zip(day)
            .map(|((y, m), d)| {
                if let (Some(y), Some(m), Some(d)) = (y, m, d) {
                    NaiveDate::from_ymd_opt(y, m as u32, d as u32).map_or_else(
                        // We have an invalid date.
                        || Err(polars_err!(ComputeError: format!("Invalid date components ({}, {}, {}) supplied", y, m, d))),
                        // We have a valid date.
                        |date| Ok(Some(date.num_days_from_ce() - EPOCH_DAYS_FROM_CE)),
                    )
                } else {
                    Ok(None)
                }
            })
            .try_collect_ca_with_dtype(name, DataType::Int32)?;
        Ok(ca.into_date())
    }
}

impl DateMethods for DateChunked {
    fn parse_from_str_slice(name: PlSmallStr, v: &[&str], fmt: &str) -> DateChunked {
        Int32Chunked::from_iter_options(
            name,
            v.iter().map(|s| {
                NaiveDate::parse_from_str(s, fmt)
                    .ok()
                    .as_ref()
                    .map(|v| naive_date_to_date(*v))
            }),
        )
        .into_date()
    }
}

pub trait AsDate {
    fn as_date(&self) -> &DateChunked;
}

impl AsDate for DateChunked {
    fn as_date(&self) -> &DateChunked {
        self
    }
}
