// Take a look at the license at the top of the repository in the LICENSE file.

use std::{boxed::Box as Box_, mem::transmute, slice, str};

use glib::{
    signal::{connect_raw, SignalHandlerId},
    translate::*,
};
use libc::{c_char, c_int};

use crate::{prelude::*, TextBuffer, TextIter, TextTag};

mod sealed {
    pub trait Sealed {}
    impl<T: super::IsA<super::TextBuffer>> Sealed for T {}
}

// rustdoc-stripper-ignore-next
/// Trait containing manually implemented methods of
/// [`TextBuffer`](crate::TextBuffer).
pub trait TextBufferExtManual: sealed::Sealed + IsA<TextBuffer> + 'static {
    // rustdoc-stripper-ignore-next
    /// # Panics
    ///
    /// If the properties don't exists or are not writeable.
    // rustdoc-stripper-ignore-next-stop
    /// Creates a tag and adds it to the tag table for @self.
    ///
    /// Equivalent to calling [`TextTag::new()`][crate::TextTag::new()] and then adding the
    /// tag to the buffer’s tag table. The returned tag is owned by
    /// the buffer’s tag table, so the ref count will be equal to one.
    ///
    /// If @tag_name is [`None`], the tag is anonymous.
    ///
    /// If @tag_name is non-[`None`], a tag called @tag_name must not already
    /// exist in the tag table for this buffer.
    ///
    /// The @first_property_name argument and subsequent arguments are a list
    /// of properties to set on the tag, as with g_object_set().
    /// ## `tag_name`
    /// name of the new tag
    /// ## `first_property_name`
    /// name of first property to set
    ///
    /// # Returns
    ///
    /// a new tag
    #[doc(alias = "gtk_text_buffer_create_tag")]
    fn create_tag(
        &self,
        tag_name: Option<&str>,
        properties: &[(&str, &dyn ToValue)],
    ) -> Option<TextTag> {
        let tag = TextTag::new(tag_name);
        tag.set_properties(properties);
        if self.as_ref().tag_table().add(&tag) {
            Some(tag)
        } else {
            None
        }
    }

    /// Inserts @text into @self at @iter, applying the list of tags to
    /// the newly-inserted text.
    ///
    /// The last tag specified must be [`None`] to terminate the list.
    /// Equivalent to calling [`TextBufferExt::insert()`][crate::prelude::TextBufferExt::insert()],
    /// then [`TextBufferExt::apply_tag()`][crate::prelude::TextBufferExt::apply_tag()] on the inserted text;
    /// this is just a convenience function.
    /// ## `iter`
    /// an iterator in @self
    /// ## `text`
    /// UTF-8 text
    /// ## `len`
    /// length of @text, or -1
    /// ## `first_tag`
    /// first tag to apply to @text
    #[doc(alias = "gtk_text_buffer_insert_with_tags")]
    fn insert_with_tags(&self, iter: &mut TextIter, text: &str, tags: &[&TextTag]) {
        let start_offset = iter.offset();
        self.as_ref().insert(iter, text);
        let start_iter = self.as_ref().iter_at_offset(start_offset);
        tags.iter().for_each(|tag| {
            self.as_ref().apply_tag(&(*tag).clone(), &start_iter, iter);
        });
    }

    /// Inserts @text into @self at @iter, applying the list of tags to
    /// the newly-inserted text.
    ///
    /// Same as [`insert_with_tags()`][Self::insert_with_tags()], but allows you
    /// to pass in tag names instead of tag objects.
    /// ## `iter`
    /// position in @self
    /// ## `text`
    /// UTF-8 text
    /// ## `len`
    /// length of @text, or -1
    /// ## `first_tag_name`
    /// name of a tag to apply to @text
    #[doc(alias = "gtk_text_buffer_insert_with_tags_by_name")]
    fn insert_with_tags_by_name(&self, iter: &mut TextIter, text: &str, tags_names: &[&str]) {
        let start_offset = iter.offset();
        self.as_ref().insert(iter, text);
        let start_iter = self.as_ref().iter_at_offset(start_offset);
        let tag_table = self.as_ref().tag_table();
        tags_names.iter().for_each(|tag_name| {
            if let Some(tag) = tag_table.lookup(tag_name) {
                self.as_ref().apply_tag(&tag, &start_iter, iter);
            } else {
                glib::g_warning!("TextBuffer", "No tag with name {}!", tag_name);
            }
        });
    }

    /// Emitted to insert text in a [`TextBuffer`][crate::TextBuffer].
    ///
    /// Insertion actually occurs in the default handler.
    ///
    /// Note that if your handler runs before the default handler
    /// it must not invalidate the @location iter (or has to
    /// revalidate it). The default signal handler revalidates
    /// it to point to the end of the inserted text.
    ///
    /// See also: [`TextBufferExt::insert()`][crate::prelude::TextBufferExt::insert()],
    /// [`TextBufferExt::insert_range()`][crate::prelude::TextBufferExt::insert_range()].
    /// ## `location`
    /// position to insert @text in @textbuffer
    /// ## `text`
    /// the UTF-8 text to be inserted
    /// ## `len`
    /// length of the inserted text in bytes
    fn connect_insert_text<F: Fn(&Self, &mut TextIter, &str) + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe {
            unsafe extern "C" fn insert_text_trampoline<
                T,
                F: Fn(&T, &mut TextIter, &str) + 'static,
            >(
                this: *mut ffi::GtkTextBuffer,
                location: *mut ffi::GtkTextIter,
                text: *mut c_char,
                len: c_int,
                f: glib::ffi::gpointer,
            ) where
                T: IsA<TextBuffer>,
            {
                let mut location_copy = from_glib_none(location);
                let f: &F = &*(f as *const F);
                let text = if len <= 0 {
                    &[]
                } else {
                    slice::from_raw_parts(text as *const u8, len as usize)
                };

                f(
                    TextBuffer::from_glib_borrow(this).unsafe_cast_ref(),
                    &mut location_copy,
                    str::from_utf8(text).unwrap(),
                )
            }
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.to_glib_none().0 as *mut _,
                b"insert-text\0".as_ptr() as *mut _,
                Some(transmute(insert_text_trampoline::<Self, F> as usize)),
                Box_::into_raw(f),
            )
        }
    }
}

impl<O: IsA<TextBuffer>> TextBufferExtManual for O {}

impl std::fmt::Write for TextBuffer {
    fn write_str(&mut self, s: &str) -> std::fmt::Result {
        let mut iter = self.end_iter();
        self.insert(&mut iter, s);
        Ok(())
    }
}