use super::elements::*;
use chrono::prelude::*;

macro_rules! block {
    ($inner:expr) => {
        Element::Block(Box::new($inner))
    };
}

#[allow(unused)]
macro_rules! inline {
    ($inner:expr) => {
        Element::Inline(Box::new($inner))
    };
}

macro_rules! subtext {
    ($inner:expr) => {
        Element::SubText(Box::new($inner))
    };
}

pub(crate) trait ProcessPlaceholders {
    fn process_placeholders(&mut self);
}

const P_TOC: &str = "toc";
const P_DATE: &str = "date";
const P_TIME: &str = "time";
const P_DATETIME: &str = "datetime";

impl ProcessPlaceholders for Document {
    /// parses all placeholders and assigns values to them
    fn process_placeholders(&mut self) {
        self.placeholders.iter().for_each(|p| {
            let mut pholder = p.lock().unwrap();
            match pholder.name.to_ascii_lowercase().as_str() {
                P_TOC => pholder.set_value(block!(Block::List(self.create_toc()))),
                P_DATE => pholder.set_value(subtext!(SubText::Plain(PlainText {
                    value: get_date_string()
                }))),
                P_TIME => pholder.set_value(subtext!(SubText::Plain(PlainText {
                    value: get_time_string()
                }))),
                P_DATETIME => pholder.set_value(subtext!(SubText::Plain(PlainText {
                    value: format!("{} {}", get_date_string(), get_time_string())
                }))),
                _ => {}
            }
        })
    }
}

fn get_time_string() -> String {
    let now = Local::now();
    format!("{:02}:{:02}:{02}", now.hour(), now.minute(), now.second())
}

fn get_date_string() -> String {
    let now = Local::now();
    format!("{:02}.{:02}.{:04}", now.day(), now.month(), now.year())
}