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

use std::cmp::Ordering;

use glib::{prelude::*, translate::*, Object};

use crate::{prelude::*, ListModel, ListStore};

impl ListStore {
    /// Inserts `item` into `self` at a position to be determined by the
    /// `compare_func`.
    ///
    /// The list must already be sorted before calling this function or the
    /// result is undefined. Usually you would approach this by only ever
    /// inserting items by way of this function.
    ///
    /// This function takes a ref on `item`.
    /// ## `item`
    /// the new item
    /// ## `compare_func`
    /// pairwise comparison function for sorting
    ///
    /// # Returns
    ///
    /// the position at which `item` was inserted
    #[doc(alias = "g_list_store_insert_sorted")]
    pub fn insert_sorted<P: IsA<glib::Object>, F: FnMut(&Object, &Object) -> Ordering>(
        &self,
        item: &P,
        compare_func: F,
    ) -> u32 {
        unsafe {
            let mut func = compare_func;
            let func_obj: &mut (dyn FnMut(&Object, &Object) -> Ordering) = &mut func;
            let func_ptr = &func_obj as *const &mut (dyn FnMut(&Object, &Object) -> Ordering)
                as glib::ffi::gpointer;

            ffi::g_list_store_insert_sorted(
                self.to_glib_none().0,
                item.as_ref().to_glib_none().0,
                Some(compare_func_trampoline),
                func_ptr,
            )
        }
    }

    /// Sort the items in `self` according to `compare_func`.
    /// ## `compare_func`
    /// pairwise comparison function for sorting
    #[doc(alias = "g_list_store_sort")]
    pub fn sort<F: FnMut(&Object, &Object) -> Ordering>(&self, compare_func: F) {
        unsafe {
            let mut func = compare_func;
            let func_obj: &mut (dyn FnMut(&Object, &Object) -> Ordering) = &mut func;
            let func_ptr = &func_obj as *const &mut (dyn FnMut(&Object, &Object) -> Ordering)
                as glib::ffi::gpointer;

            ffi::g_list_store_sort(
                self.to_glib_none().0,
                Some(compare_func_trampoline),
                func_ptr,
            )
        }
    }

    /// Changes `self` by removing `n_removals` items and adding `n_additions`
    /// items to it. `additions` must contain `n_additions` items of type
    /// [`item-type`][struct@crate::ListStore#item-type]. [`None`] is not permitted.
    ///
    /// This function is more efficient than [`insert()`][Self::insert()] and
    /// [`remove()`][Self::remove()], because it only emits
    /// [`items-changed`][struct@crate::ListModel#items-changed] once for the change.
    ///
    /// This function takes a ref on each item in `additions`.
    ///
    /// The parameters `position` and `n_removals` must be correct (ie:
    /// `position` + `n_removals` must be less than or equal to the length of
    /// the list at the time this function is called).
    /// ## `position`
    /// the position at which to make the change
    /// ## `n_removals`
    /// the number of items to remove
    /// ## `additions`
    /// the items to add
    #[doc(alias = "g_list_store_splice")]
    pub fn splice(&self, position: u32, n_removals: u32, additions: &[impl IsA<glib::Object>]) {
        let n_additions = additions.len() as u32;
        unsafe {
            let additions = additions.as_ptr() as *mut *mut glib::gobject_ffi::GObject;

            ffi::g_list_store_splice(
                self.to_glib_none().0,
                position,
                n_removals,
                additions,
                n_additions,
            );
        }
    }

    // rustdoc-stripper-ignore-next
    /// Appends all elements in a slice to the `ListStore`.
    pub fn extend_from_slice(&self, additions: &[impl IsA<glib::Object>]) {
        self.splice(self.n_items(), 0, additions)
    }

    /// Looks up the given `item` in the list store by looping over the items and
    /// comparing them with `equal_func` until the first occurrence of `item` which
    /// matches. If `item` was not found, then `position` will not be set, and this
    /// method will return [`false`].
    /// ## `item`
    /// an item
    /// ## `equal_func`
    /// A custom equality check function
    ///
    /// # Returns
    ///
    /// Whether `self` contains `item`. If it was found, `position` will be
    /// set to the position where `item` occurred for the first time.
    ///
    /// ## `position`
    /// the first position of `item`, if it was found.
    #[cfg(any(feature = "v2_74", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v2_74")))]
    #[doc(alias = "g_list_store_find_with_equal_func_full")]
    #[doc(alias = "g_list_store_find_with_equal_func")]
    pub fn find_with_equal_func<F: FnMut(&glib::Object) -> bool>(
        &self,
        equal_func: F,
    ) -> Option<u32> {
        unsafe extern "C" fn equal_func_trampoline(
            a: glib::ffi::gconstpointer,
            _b: glib::ffi::gconstpointer,
            func: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            let func = func as *mut &mut (dyn FnMut(&Object) -> bool);

            let a = from_glib_borrow(a as *mut glib::gobject_ffi::GObject);

            (*func)(&a).into_glib()
        }

        unsafe {
            // GIO requires a non-NULL item to be passed in so we're constructing a fake item here.
            // See https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3284
            let item = glib::gobject_ffi::GObject {
                g_type_instance: glib::gobject_ffi::GTypeInstance {
                    g_class: glib::gobject_ffi::g_type_class_peek(self.item_type().into_glib())
                        as *mut _,
                },
                ref_count: 1,
                qdata: std::ptr::null_mut(),
            };
            let mut func = equal_func;
            let func_obj: &mut (dyn FnMut(&Object) -> bool) = &mut func;
            let func_ptr =
                &func_obj as *const &mut (dyn FnMut(&Object) -> bool) as glib::ffi::gpointer;

            let mut position = std::mem::MaybeUninit::uninit();

            let found = bool::from_glib(ffi::g_list_store_find_with_equal_func_full(
                self.to_glib_none().0,
                mut_override(&item as *const _),
                Some(equal_func_trampoline),
                func_ptr,
                position.as_mut_ptr(),
            ));

            found.then(|| position.assume_init())
        }
    }
}

impl<P: IsA<glib::Object>> std::iter::FromIterator<P> for ListStore {
    fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> Self {
        let store = Self::new(P::static_type());
        for item in iter.into_iter() {
            store.append(&item)
        }
        store
    }
}

impl<'a> std::iter::IntoIterator for &'a ListStore {
    type Item = <&'a ListModel as IntoIterator>::Item;
    type IntoIter = <&'a ListModel as IntoIterator>::IntoIter;

    fn into_iter(self) -> Self::IntoIter {
        self.upcast_ref::<ListModel>().into_iter()
    }
}

unsafe extern "C" fn compare_func_trampoline(
    a: glib::ffi::gconstpointer,
    b: glib::ffi::gconstpointer,
    func: glib::ffi::gpointer,
) -> i32 {
    let func = func as *mut &mut (dyn FnMut(&Object, &Object) -> Ordering);

    let a = from_glib_borrow(a as *mut glib::gobject_ffi::GObject);
    let b = from_glib_borrow(b as *mut glib::gobject_ffi::GObject);

    (*func)(&a, &b).into_glib()
}

impl<A: AsRef<glib::Object>> std::iter::Extend<A> for ListStore {
    fn extend<T: IntoIterator<Item = A>>(&mut self, iter: T) {
        let additions = iter
            .into_iter()
            .map(|o| o.as_ref().clone())
            .collect::<Vec<_>>();
        self.splice(self.n_items(), 0, &additions)
    }
}

#[cfg(test)]
mod tests {
    use crate::{prelude::*, ListStore};

    #[test]
    fn splice() {
        let item0 = ListStore::new(ListStore::static_type());
        let item1 = ListStore::new(ListStore::static_type());
        let list = ListStore::new(ListStore::static_type());
        list.splice(0, 0, &[item0.clone(), item1.clone()]);
        assert_eq!(list.item(0), Some(item0.upcast()));
        assert_eq!(list.item(1), Some(item1.upcast()));
    }

    #[test]
    fn extend() {
        let item0 = ListStore::new(ListStore::static_type());
        let item1 = ListStore::new(ListStore::static_type());
        let mut list = ListStore::new(ListStore::static_type());
        list.extend([&item0, &item1]);
        assert_eq!(list.item(0).as_ref(), Some(item0.upcast_ref()));
        assert_eq!(list.item(1).as_ref(), Some(item1.upcast_ref()));
        list.extend([item0.clone(), item1.clone()]);
        assert_eq!(list.item(2).as_ref(), Some(item0.upcast_ref()));
        assert_eq!(list.item(3).as_ref(), Some(item1.upcast_ref()));

        let list_from_slice = ListStore::new(ListStore::static_type());
        list_from_slice.extend_from_slice(&[item0, item1.clone()]);
        assert_eq!(list_from_slice.item(1).as_ref(), Some(item1.upcast_ref()));
    }

    #[test]
    fn from_iterator() {
        let item0 = ListStore::new(ListStore::static_type());
        let item1 = ListStore::new(ListStore::static_type());
        let v = vec![item0.clone(), item1.clone()];
        let list = ListStore::from_iter(v);
        assert_eq!(list.item(0).as_ref(), Some(item0.upcast_ref()));
        assert_eq!(list.item(1).as_ref(), Some(item1.upcast_ref()));
        assert_eq!(list.item(2).as_ref(), None);
    }

    #[cfg(feature = "v2_74")]
    #[test]
    fn find() {
        let item0 = ListStore::new(ListStore::static_type());
        let item1 = ListStore::new(ListStore::static_type());
        let list = ListStore::new(ListStore::static_type());
        list.append(&item0);
        list.append(&item1);

        let res = list.find_with_equal_func(|item| item == &item1);
        assert_eq!(res, Some(1));
    }
}