use chrono::{Datelike, NaiveDate};

use crate::eval::date::Dates;
use crate::files::commands::BirthdaySpec;

use super::super::command::CommandState;
use super::super::{Entry, EntryKind};

impl<'a> CommandState<'a> {
    pub fn eval_birthday_spec(&mut self, spec: &BirthdaySpec) {
        // This could be optimized by restricting the range via FROM and UNTIL,
        // but I don't think that kind of optimization will be necessary any
        // time soon.
        for year in self.range.years() {
            let mut title = self.title();

            if spec.year_known {
                let age = year - spec.date.year();
                if age < 0 {
                    continue;
                }
                title.push_str(&format!(" ({})", age));
            }

            if let Some(date) = spec.date.with_year(year) {
                self.add(Entry {
                    kind: EntryKind::Birthday,
                    title,
                    desc: self.desc(),
                    source: self.source(),
                    root: Some(date),
                    dates: Some(Dates::new(date, date)),
                });
            } else {
                assert_eq!(spec.date.month(), 2);
                assert_eq!(spec.date.day(), 29);

                let first = NaiveDate::from_ymd(year, 2, 28);
                let second = NaiveDate::from_ymd(year, 3, 1);
                self.add(Entry {
                    kind: EntryKind::Birthday,
                    title,
                    desc: self.desc(),
                    source: self.source(),
                    root: Some(first), // This doesn't matter too much
                    dates: Some(Dates::new(first, second)),
                });
            }
        }
    }
}