use std::path::PathBuf;
use std::ops::Deref;

use anyhow::Result;
use anyhow::Context;
use cursive::Cursive;
use cursive::Printer;
use cursive::Rect;
use cursive::View;
use cursive::XY;
use cursive::direction::Direction;
use cursive::view::Nameable;
use cursive::view::Selector;
use cursive::event::Event;
use cursive::event::EventResult;
use cursive::views::NamedView;
use cursive_table_view::TableView;
use cursive_table_view::TableViewItem;
use chrono::naive::NaiveDateTime;
use notmuch::Message;
use notmuch::MessageOwner;
use getset::Getters;
use cursive::views::ResizedView;
use cursive::view::SizeConstraint;

use crate::main_view::MainView;
use crate::mail_view::MailView;

pub struct MaillistView {
    view: ResizedView<TableView<MailListingData, MailListingColumn>>,
}

impl Deref for MaillistView {
    type Target = TableView<MailListingData, MailListingColumn>;
    fn deref(&self) -> &Self::Target {
        self.view.get_inner()
    }
}

impl MaillistView {
    pub fn create_for(database_path: PathBuf, query: &str, name: String) -> Result<NamedView<Self>> {
        debug!("Getting '{}' from '{}'", query, database_path.display());

        fn get_header_field_save<'o, O: MessageOwner + 'o>(msg: &Message<'o, O>, field: &str) -> String {
            match msg.header(field) {
                Err(e) => {
                    error!("Failed getting '{}' of '{}': {}", field, msg.id(), e);
                    String::from("---")
                },

                Ok(None) => format!("No Value for {}", field),
                Ok(Some(f)) => f.to_string(),
            }
        }

        let items = notmuch::Database::open(&database_path, notmuch::DatabaseMode::ReadOnly)
            .context(format!("Opening database {}", database_path.display()))?
            .create_query(query)
            .context("Creating the search query")?
            .search_messages()
            .context(format!("Searching for messages with '{}'", query))?
            .map(|msg| {
                let mail_id  = msg.id().to_string();
                let filename = msg.filename();
                let tags     = msg.tags().collect();
                let date     = NaiveDateTime::from_timestamp_opt(msg.date(), 0)
                        .map(|ndt| ndt.to_string())
                        .ok_or_else(|| {
                            error!("Failed to parse timestamp: {}", msg.date());
                            anyhow!("Failed to parse timestamp: {}", msg.date())
                        })
                        .context(format!("Getting the date of message {}", msg.id()))?;

                let from    = get_header_field_save(&msg, "From");
                let to      = get_header_field_save(&msg, "To");
                let subject = get_header_field_save(&msg, "Subject");

                Ok(MailListingData {
                    mail_id,
                    filename,
                    tags,
                    date,
                    from,
                    to,
                    subject,
                })
            })
            .collect::<Result<Vec<_>>>()
            .context(format!("Creating MaillinglistView for '{}' on {}", query, database_path.display()))?;

        debug!("Found {} entries", items.len());
        let n = name.clone();
        let db_path = database_path.clone();
        let view = TableView::<MailListingData, MailListingColumn>::new()
                .column(MailListingColumn::Date, "Date", |c| c.width(20))
                .column(MailListingColumn::Tags, "Tags", |c| c.width(20))
                .column(MailListingColumn::From, "From", |c| c)
                .column(MailListingColumn::To, "To", |c| c)
                .column(MailListingColumn::Subject, "Subject", |c| c)
                .default_column(MailListingColumn::Date)
                .items(items)
                .selected_item(0)
                .on_submit(move |siv: &mut Cursive, row: usize, _: usize| {
                    let (mail_id, filename) = siv.call_on_name(&n, move |table: &mut MaillistView| {
                        table.view
                            .get_inner_mut()
                            .borrow_item(row)
                            .map(|data| {
                                debug!("Opening: {:?}", data);
                                (data.mail_id.clone(), data.filename.clone())
                            })
                    })
                    .unwrap()
                    .unwrap();

                    debug!("Showing mail {}", mail_id);

                    // Why do I have to do this? This is UGLY!
                    let n = n.clone();
                    let db_path = db_path.clone();

                    siv.call_on_name(crate::main_view::MAIN_VIEW_NAME, move |main_view: &mut MainView| {
                        let name = format!("{}-{}", n, mail_id);
                        debug!("Creating MailView '{}' for {} ({}) in {}", name, mail_id, filename.display(), db_path.display());
                        let mv = MailView::create_for(db_path, mail_id, filename, name.clone()).unwrap();

                        main_view.add_tab(name, mv);
                    });

                    // use the mail ID to get the whole thread and open it as a table item
                });

        Ok(MaillistView { view: ResizedView::new(SizeConstraint::Full, SizeConstraint::Full, view )}.with_name(name))
    }

    pub fn borrow_item(&mut self, idx: usize) -> Option<&MailListingData> {
        self.view.get_inner_mut().borrow_item(idx)
    }
}

impl View for MaillistView {
    fn draw(&self, printer: &Printer) {
        self.view.draw(printer)
    }

    fn layout(&mut self, xy: XY<usize>) {
        self.view.layout(xy)
    }

    fn needs_relayout(&self) -> bool {
        self.view.needs_relayout()
    }

    fn required_size(&mut self, constraint: XY<usize>) -> XY<usize> {
        self.view.required_size(constraint)
    }

    fn on_event(&mut self, e: Event) -> EventResult {
        self.view.on_event(e)
    }

    fn call_on_any<'a>(&mut self, s: &Selector, tpl: &'a mut (dyn FnMut(&mut (dyn View + 'static)) + 'a)) {
        self.view.call_on_any(s, tpl);
    }

    fn focus_view(&mut self, s: &Selector) -> Result<(), ()> {
        self.view.focus_view(s)
    }

    fn take_focus(&mut self, source: Direction) -> bool {
        self.view.take_focus(source)
    }

    fn important_area(&self, view_size: XY<usize>) -> Rect {
        self.view.important_area(view_size)
    }

    fn type_name(&self) -> &'static str {
        self.view.type_name()
    }

}

#[derive(Copy, Clone, PartialEq, Eq, Hash)]
pub enum MailListingColumn {
    Date,
    Tags,
    From,
    To,
    Subject,
}

#[derive(Clone, Debug, Getters)]
pub struct MailListingData {
    #[getset(get = "pub")]
    mail_id: String,

    #[getset(get = "pub")]
    filename: PathBuf,

    #[getset(get = "pub")]
    tags: Vec<String>,

    #[getset(get = "pub")]
    date: String,

    #[getset(get = "pub")]
    from: String,

    #[getset(get = "pub")]
    to: String,

    #[getset(get = "pub")]
    subject: String,
}

impl TableViewItem<MailListingColumn> for MailListingData {

    fn to_column(&self, column: MailListingColumn) -> String {
        match column {
            MailListingColumn::Date    => self.date.clone(),
            MailListingColumn::Tags    => self.tags.join(", "),
            MailListingColumn::From    => self.from.clone(),
            MailListingColumn::To      => self.to.clone(),
            MailListingColumn::Subject => self.subject.clone(),
        }
    }

    fn cmp(&self, other: &Self, column: MailListingColumn) -> std::cmp::Ordering
        where Self: Sized
    {
        match column {
            MailListingColumn::Date    => self.date.cmp(&other.date),
            MailListingColumn::Tags    => self.tags.cmp(&other.tags),
            MailListingColumn::From    => self.from.cmp(&other.from),
            MailListingColumn::To      => self.to.cmp(&other.to),
            MailListingColumn::Subject => self.subject.cmp(&other.subject),
        }
    }

}