use std::collections::HashMap;
use chrono::{NaiveDate, NaiveDateTime};

mod tokenizer;
mod parser;
pub use parser::Parser;

pub trait GetValue<'a, R: 'a> {
    fn get(&'a self, key: &'_ str) -> Option<R>;
}

pub type Props = Vec<(String, String)>;

#[derive(Debug, PartialEq)]
pub struct Object {
    pub name: String,
    pub content: HashMap<String, (Props, String)>,
    pub children: Vec<Box<Object>>,
}

impl<'a> GetValue<'a, &'a str> for Object {
    fn get(&'a self, key: &'_ str) -> Option<&'a str> {
        self.content.get(key)
            .map(|(_props, value)| value.as_ref())
    }
}

impl<'a> GetValue<'a, String> for Object {
    fn get(&self, key: &'_ str) -> Option<String> {
        self.content.get(key)
            .map(|(_props, value)| value.clone())
    }
}

// TODO: TZID, offset
// TODO: enum for all day events?
impl<'a> GetValue<'a, NaiveDateTime> for Object {
    fn get(&self, key: &'_ str) -> Option<NaiveDateTime> {
        let s = self.get(key)?;
        NaiveDateTime::parse_from_str(s, "%Y%m%dT%H%M%SZ")
            .or_else(|_| NaiveDateTime::parse_from_str(s, "%Y%m%dT%H%M%S"))
            .or_else(|_|
                 NaiveDate::parse_from_str(s, "%Y%m%d")
                 .map(|date| date.and_hms(0, 0, 0))
            )
            .map_err(|e| println!("Cannot parse date: {:?}", e))
            .ok()
    }
}