//! A text buffer abstraction
//!
//! Because of the separation between novelist-data and novelist-gtk
//! the storage buffer can't rely on the Gtk buffer to fill data and
//! set tag data.  This module wraps this relationship

use gtk4::{prelude::TextBufferExt, TextBuffer, TextTagTable};
use novelist_data::{Buffer, Format, PopulateBuffer, TagEntry};
use std::sync::Arc;

pub struct GtkBuffer(TextBuffer);

impl GtkBuffer {
    pub fn new(tb: TextBuffer) -> Self {
        Self(tb)
    }

    pub fn consume(self) -> TextBuffer {
        self.0
    }
}

impl PopulateBuffer for GtkBuffer {
    fn populate(&self, storage: &Buffer) {
        let content = storage.content.lock().unwrap();

        self.0.set_text(&content);
        storage
            .tags
            .lock()
            .unwrap()
            .iter()
            .for_each(|TagEntry { start, end, style }| {
                self.0.apply_tag_by_name(
                    match style {
                        Format::Bold => "bold",
                        Format::Italics => "italics",
                        _ => unimplemented!(),
                    },
                    &self.0.iter_at_offset(*start),
                    &self.0.iter_at_offset(*end),
                )
            })
    }
}

/// Create an empty text buffer
pub fn empty(text_tag_table: &TextTagTable) -> TextBuffer {
    TextBuffer::new(Some(&text_tag_table))
}

/// Load a text buffer from a store
pub fn from_store(text_tag_table: &TextTagTable, buffer: &Arc<Buffer>) -> TextBuffer {
    let gtk_buffer = GtkBuffer(empty(text_tag_table));
    buffer.populate_ui(&gtk_buffer);
    gtk_buffer.0
}