/*
Copyright 2023, Savanni D'Gerinel <savanni@luminescent-dreams.com>

This file is part of FitnessTrax.

FitnessTrax is free software: you can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

FitnessTrax is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along with FitnessTrax. If not, see <https://www.gnu.org/licenses/>.
*/

use crate::components::DaySummary;
use chrono::{Duration, Local, NaiveDate};
use emseries::Record;
use ft_core::TraxRecord;
use glib::Object;
use gtk::{prelude::*, subclass::prelude::*};
use std::{cell::RefCell, collections::HashMap, rc::Rc};

/// The historical view will show a window into the main database. It will show some version of
/// daily summaries, daily details, and will provide all functions the user may need for editing
/// records.
pub struct HistoricalViewPrivate {
    time_window: RefCell<DayInterval>,
}

#[glib::object_subclass]
impl ObjectSubclass for HistoricalViewPrivate {
    const NAME: &'static str = "HistoricalView";
    type Type = HistoricalView;
    type ParentType = gtk::Box;

    fn new() -> Self {
        Self {
            time_window: RefCell::new(DayInterval::default()),
        }
    }
}

impl ObjectImpl for HistoricalViewPrivate {}
impl WidgetImpl for HistoricalViewPrivate {}
impl BoxImpl for HistoricalViewPrivate {}

glib::wrapper! {
    pub struct HistoricalView(ObjectSubclass<HistoricalViewPrivate>) @extends gtk::Box, gtk::Widget, @implements gtk::Orientable;
}

impl HistoricalView {
    pub fn new<SelectFn>(records: Vec<Record<TraxRecord>>, on_select_day: Rc<SelectFn>) -> Self
    where
        SelectFn: Fn(chrono::NaiveDate, Vec<Record<TraxRecord>>) + 'static,
    {
        let s: Self = Object::builder().build();
        s.set_orientation(gtk::Orientation::Vertical);
        s.set_css_classes(&["historical"]);

        let grouped_records =
            GroupedRecords::new((*s.imp().time_window.borrow()).clone()).with_data(records);

        let mut model = gio::ListStore::new::<DayRecords>();
        model.extend(grouped_records.items());

        let factory = gtk::SignalListItemFactory::new();
        factory.connect_setup(move |_, list_item| {
            list_item
                .downcast_ref::<gtk::ListItem>()
                .expect("should be a ListItem")
                .set_child(Some(&DaySummary::new()));
        });

        factory.connect_bind(move |_, list_item| {
            let records = list_item
                .downcast_ref::<gtk::ListItem>()
                .expect("should be a ListItem")
                .item()
                .and_downcast::<DayRecords>()
                .expect("should be a DaySummary");

            let summary = list_item
                .downcast_ref::<gtk::ListItem>()
                .expect("should be a ListItem")
                .child()
                .and_downcast::<DaySummary>()
                .expect("should be a DaySummary");

            summary.set_data(records.date(), records.records());
        });

        let lst = gtk::ListView::builder()
            .model(&gtk::NoSelection::new(Some(model)))
            .factory(&factory)
            .single_click_activate(true)
            .build();
        lst.connect_activate({
            let on_select_day = on_select_day.clone();
            move |s, idx| {
                // This gets triggered whenever the user clicks on an item on the list. What we
                // actually want to do here is to open a modal dialog that shows all of the details of
                // the day and which allows the user to edit items within that dialog.
                let item = s.model().unwrap().item(idx).unwrap();
                let records = item.downcast_ref::<DayRecords>().unwrap();
                on_select_day(records.date(), records.records());
            }
        });

        s.append(&lst);

        s
    }
}

#[derive(Default)]
pub struct DayRecordsPrivate {
    date: RefCell<chrono::NaiveDate>,
    records: RefCell<Vec<Record<TraxRecord>>>,
}

#[glib::object_subclass]
impl ObjectSubclass for DayRecordsPrivate {
    const NAME: &'static str = "DayRecords";
    type Type = DayRecords;
}

impl ObjectImpl for DayRecordsPrivate {}

glib::wrapper! {
    pub struct DayRecords(ObjectSubclass<DayRecordsPrivate>);
}

impl DayRecords {
    pub fn new(date: chrono::NaiveDate, records: Vec<Record<TraxRecord>>) -> Self {
        let s: Self = Object::builder().build();

        *s.imp().date.borrow_mut() = date;
        *s.imp().records.borrow_mut() = records;

        s
    }

    pub fn date(&self) -> chrono::NaiveDate {
        self.imp().date.borrow().clone()
    }

    pub fn records(&self) -> Vec<Record<TraxRecord>> {
        self.imp().records.borrow().clone()
    }

    pub fn add_record(&self, record: Record<TraxRecord>) {
        self.imp().records.borrow_mut().push(record);
    }
}

struct GroupedRecords {
    interval: DayInterval,
    data: HashMap<NaiveDate, DayRecords>,
}

impl GroupedRecords {
    fn new(interval: DayInterval) -> Self {
        let mut s = Self {
            interval: interval.clone(),
            data: HashMap::new(),
        };
        interval.days().for_each(|date| {
            let _ = s.data.insert(date, DayRecords::new(date, vec![]));
        });
        s
    }

    fn with_data(mut self, records: Vec<Record<TraxRecord>>) -> Self {
        records.into_iter().for_each(|record| {
            self.data
                .entry(record.date())
                .and_modify(|entry: &mut DayRecords| (*entry).add_record(record.clone()))
                .or_insert(DayRecords::new(record.date(), vec![record]));
        });

        self
    }

    fn items<'a>(&'a self) -> impl Iterator<Item = DayRecords> + 'a {
        /*
        GroupedRecordIterator {
            interval: self.interval.clone(),
            data: &self.data,
        }
        */
        self.interval.days().map(|date| {
            self.data
                .get(&date)
                .map(|rec| rec.clone())
                .unwrap_or(DayRecords::new(date, vec![]))
        })
    }
}

/*
struct GroupedRecordIterator<'a> {
    interval: DayInterval,
    data: &'a HashMap<NaiveDate, DayRecords>,
}

impl <'a> Iterator for GroupedRecordIterator<'a> {
    type Item = &'a DayRecords;

    fn next(&mut self) -> Option<&'a DayRecords> {

    }
}
*/

#[derive(Clone, Debug, PartialEq, Eq)]
struct DayInterval {
    start: NaiveDate,
    end: NaiveDate,
}

impl Default for DayInterval {
    fn default() -> Self {
        Self {
            start: (Local::now() - Duration::days(7)).date_naive(),
            end: Local::now().date_naive(),
        }
    }
}

impl DayInterval {
    fn days(&self) -> impl Iterator<Item = NaiveDate> {
        DayIterator {
            current: self.start.clone(),
            end: self.end.clone(),
        }
    }
}

struct DayIterator {
    current: NaiveDate,
    end: NaiveDate,
}

impl Iterator for DayIterator {
    type Item = NaiveDate;

    fn next(&mut self) -> Option<Self::Item> {
        if self.current <= self.end {
            let val = self.current.clone();
            self.current += Duration::days(1);
            Some(val)
        } else {
            None
        }
    }
}

#[cfg(test)]
mod test {
    use super::GroupedRecords;
    use chrono::{FixedOffset, NaiveDate, TimeZone};
    use dimensioned::si::{KG, M, S};
    use emseries::{Record, RecordId};
    use ft_core::{Steps, TimeDistance, TraxRecord, Weight};

    #[test]
    fn groups_records() {
        let records = vec![
            Record {
                id: RecordId::default(),
                data: TraxRecord::Steps(Steps {
                    date: NaiveDate::from_ymd_opt(2023, 10, 13).unwrap(),
                    count: 1500,
                }),
            },
            Record {
                id: RecordId::default(),
                data: TraxRecord::Weight(Weight {
                    date: NaiveDate::from_ymd_opt(2023, 10, 13).unwrap(),
                    weight: 85. * KG,
                }),
            },
            Record {
                id: RecordId::default(),
                data: TraxRecord::Weight(Weight {
                    date: NaiveDate::from_ymd_opt(2023, 10, 14).unwrap(),
                    weight: 86. * KG,
                }),
            },
            Record {
                id: RecordId::default(),
                data: TraxRecord::BikeRide(TimeDistance {
                    datetime: FixedOffset::west_opt(10 * 60 * 60)
                        .unwrap()
                        .with_ymd_and_hms(2019, 6, 15, 12, 0, 0)
                        .unwrap(),
                    distance: Some(1000. * M),
                    duration: Some(150. * S),
                    comments: Some("Test Comments".to_owned()),
                }),
            },
            Record {
                id: RecordId::default(),
                data: TraxRecord::BikeRide(TimeDistance {
                    datetime: FixedOffset::west_opt(10 * 60 * 60)
                        .unwrap()
                        .with_ymd_and_hms(2019, 6, 15, 23, 0, 0)
                        .unwrap(),
                    distance: Some(1000. * M),
                    duration: Some(150. * S),
                    comments: Some("Test Comments".to_owned()),
                }),
            },
        ];

        let groups = GroupedRecords::from(records).0;
        assert_eq!(groups.len(), 3);
    }
}