use chrono::DateTime;
use json::{object, JsonValue};
use log::error;
use rss::Channel;

pub fn build_json(channel: Channel) -> JsonValue {
    // Initialize root object with channel informations, using object macro from json crate
    let mut data = object! {
        channel: object!{
            title: channel.title(),
            link: channel.link(),
            description: channel.description(),
            last_build_date: channel.last_build_date(),
            language: channel.language(),
            copyright: channel.copyright(),
            generator: channel.generator()
        }
    };

    // declare an mutable array to populate it with channel item data
    let mut items_data = json::JsonValue::new_array();

    // populate the items array
    for item in channel.items() {
        let pub_datetime = DateTime::parse_from_rfc2822(item.pub_date().unwrap()).unwrap();

        // create object to hold item data
        let mut item_data = object! {
        title: item.title(),
        link: item.link(),
        pub_date: item.pub_date(),
        pub_ts: pub_datetime.timestamp(),
        description: item.description(),
        // author: item.author()
        };

        // populate categories
        let mut categories = json::JsonValue::new_array();

        for category in item.categories() {
            match categories.push(category.name()) {
                Ok(_) => {}
                Err(e) => {
                    // memory overflow ? as a beginner, style puzzled by rust
                    error!("Error pushing to items_data {}", e);
                }
            }
        }

        item_data["categories"] = categories;

        if item.content().is_some() {
            item_data["content"] = json::JsonValue::String(item.content().unwrap().to_string());
        }

        match items_data.push(item_data) {
            Ok(_) => {}
            Err(e) => {
                // memory overflow ? as a beginner, style puzzled by rust
                error!("Error pushing to items_data {}", e);
            }
        }
    }

    // attach the items to the json data root
    data["items"] = items_data;
    return data;
}