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

use glib::object::{Cast, IsA};
use glib::translate::*;
use std::cmp::Ordering;
use std::fmt;
use std::mem;

use crate::{SortType, TreeIter, TreeModel, TreeSortable};

#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum SortColumn {
    #[doc(alias = "GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID")]
    Default,
    Index(u32),
}

#[doc(hidden)]
impl IntoGlib for SortColumn {
    type GlibType = i32;

    #[inline]
    fn into_glib(self) -> i32 {
        match self {
            SortColumn::Default => ffi::GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID,
            SortColumn::Index(x) => {
                assert!(x <= i32::max_value() as u32, "column index is too big");
                x as i32
            }
        }
    }
}

#[doc(hidden)]
impl FromGlib<i32> for SortColumn {
    #[inline]
    unsafe fn from_glib(val: i32) -> Self {
        skip_assert_initialized!();
        match val {
            ffi::GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID => Self::Default,
            x => {
                assert!(x >= 0, "invalid column index");
                Self::Index(x as u32)
            }
        }
    }
}

impl fmt::Display for SortColumn {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(
            f,
            "SortColumn::{}",
            match *self {
                SortColumn::Default => "Default",
                SortColumn::Index(_) => "Index",
            }
        )
    }
}

pub trait TreeSortableExtManual: 'static {
    /// Sets the default comparison function used when sorting to be `sort_func`.
    /// If the current sort column id of `self` is
    /// `GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID`, then the model will sort using
    /// this function.
    ///
    /// If `sort_func` is [`None`], then there will be no default comparison function.
    /// This means that once the model has been sorted, it can’t go back to the
    /// default state. In this case, when the current sort column id of `self`
    /// is `GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID`, the model will be unsorted.
    /// ## `sort_func`
    /// The comparison function
    #[doc(alias = "gtk_tree_sortable_set_default_sort_func")]
    fn set_default_sort_func<F>(&self, sort_func: F)
    where
        F: Fn(&Self, &TreeIter, &TreeIter) -> Ordering + 'static;
    /// Sets the comparison function used when sorting to be `sort_func`. If the
    /// current sort column id of `self` is the same as `sort_column_id`, then
    /// the model will sort using this function.
    /// ## `sort_column_id`
    /// the sort column id to set the function for
    /// ## `sort_func`
    /// The comparison function
    #[doc(alias = "gtk_tree_sortable_set_sort_func")]
    fn set_sort_func<F>(&self, sort_column_id: SortColumn, sort_func: F)
    where
        F: Fn(&Self, &TreeIter, &TreeIter) -> Ordering + 'static;
    /// Fills in `sort_column_id` and `order` with the current sort column and the
    /// order. It returns [`true`] unless the `sort_column_id` is
    /// `GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID` or
    /// `GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID`.
    ///
    /// # Returns
    ///
    /// [`true`] if the sort column is not one of the special sort
    ///  column ids.
    ///
    /// ## `sort_column_id`
    /// The sort column id to be filled in
    ///
    /// ## `order`
    /// The [`SortType`][crate::SortType] to be filled in
    #[doc(alias = "gtk_tree_sortable_get_sort_column_id")]
    #[doc(alias = "get_sort_column_id")]
    fn sort_column_id(&self) -> Option<(SortColumn, SortType)>;
    /// Sets the current sort column to be `sort_column_id`. The `self` will
    /// resort itself to reflect this change, after emitting a
    /// `GtkTreeSortable::sort-column-changed` signal. `sort_column_id` may either be
    /// a regular column id, or one of the following special values:
    ///
    /// - `GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID`: the default sort function
    ///  will be used, if it is set
    ///
    /// - `GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID`: no sorting will occur
    /// ## `sort_column_id`
    /// the sort column id to set
    /// ## `order`
    /// The sort order of the column
    #[doc(alias = "gtk_tree_sortable_set_sort_column_id")]
    fn set_sort_column_id(&self, sort_column_id: SortColumn, order: SortType);
    #[doc(alias = "gtk_tree_sortable_set_sort_column_id")]
    fn set_unsorted(&self);
}

unsafe extern "C" fn trampoline<T, F: Fn(&T, &TreeIter, &TreeIter) -> Ordering>(
    this: *mut ffi::GtkTreeModel,
    iter: *mut ffi::GtkTreeIter,
    iter2: *mut ffi::GtkTreeIter,
    f: glib::ffi::gpointer,
) -> i32
where
    T: IsA<TreeSortable>,
{
    let f: &F = &*(f as *const F);
    f(
        &TreeModel::from_glib_none(this).unsafe_cast(),
        &from_glib_borrow(iter),
        &from_glib_borrow(iter2),
    )
    .into_glib()
}

unsafe extern "C" fn destroy_closure<T, F: Fn(&T, &TreeIter, &TreeIter) -> Ordering>(
    ptr: glib::ffi::gpointer,
) {
    Box::<F>::from_raw(ptr as *mut _);
}

fn into_raw<F, T>(func: F) -> glib::ffi::gpointer
where
    F: Fn(&T, &TreeIter, &TreeIter) -> Ordering + 'static,
{
    skip_assert_initialized!();
    let func: Box<F> = Box::new(func);
    Box::into_raw(func) as glib::ffi::gpointer
}

impl<O: IsA<TreeSortable>> TreeSortableExtManual for O {
    #[inline]
    fn sort_column_id(&self) -> Option<(SortColumn, SortType)> {
        unsafe {
            let mut sort_column_id = mem::MaybeUninit::uninit();
            let mut order = mem::MaybeUninit::uninit();
            ffi::gtk_tree_sortable_get_sort_column_id(
                self.as_ref().to_glib_none().0,
                sort_column_id.as_mut_ptr(),
                order.as_mut_ptr(),
            );
            let sort_column_id = sort_column_id.assume_init();
            if sort_column_id != ffi::GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID {
                Some((from_glib(sort_column_id), from_glib(order.assume_init())))
            } else {
                None
            }
        }
    }

    fn set_default_sort_func<F>(&self, sort_func: F)
    where
        F: Fn(&Self, &TreeIter, &TreeIter) -> Ordering + 'static,
    {
        unsafe {
            ffi::gtk_tree_sortable_set_default_sort_func(
                self.as_ref().to_glib_none().0,
                Some(trampoline::<Self, F>),
                into_raw(sort_func),
                Some(destroy_closure::<Self, F>),
            )
        }
    }

    #[inline]
    fn set_sort_column_id(&self, sort_column_id: SortColumn, order: SortType) {
        unsafe {
            ffi::gtk_tree_sortable_set_sort_column_id(
                self.as_ref().to_glib_none().0,
                sort_column_id.into_glib(),
                order.into_glib(),
            );
        }
    }

    fn set_unsorted(&self) {
        unsafe {
            ffi::gtk_tree_sortable_set_sort_column_id(
                self.as_ref().to_glib_none().0,
                ffi::GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID,
                SortType::Ascending.into_glib(),
            );
        }
    }

    fn set_sort_func<F>(&self, sort_column_id: SortColumn, sort_func: F)
    where
        F: Fn(&Self, &TreeIter, &TreeIter) -> Ordering + 'static,
    {
        unsafe {
            ffi::gtk_tree_sortable_set_sort_func(
                self.as_ref().to_glib_none().0,
                sort_column_id.into_glib(),
                Some(trampoline::<Self, F>),
                into_raw(sort_func),
                Some(destroy_closure::<Self, F>),
            )
        }
    }
}