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

use crate::EntryBuffer;
use glib::object::IsA;
use glib::translate::*;
use libc::{c_int, c_uint};

impl EntryBuffer {
    /// Create a new [`EntryBuffer`][crate::EntryBuffer] object.
    ///
    /// Optionally, specify initial text to set in the buffer.
    /// ## `initial_chars`
    /// initial buffer text
    /// ## `n_initial_chars`
    /// number of characters in `initial_chars`, or -1
    ///
    /// # Returns
    ///
    /// A new [`EntryBuffer`][crate::EntryBuffer] object.
    #[doc(alias = "gtk_entry_buffer_new")]
    pub fn new(initial_chars: Option<&str>) -> Self {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_full(ffi::gtk_entry_buffer_new(
                initial_chars.to_glib_none().0,
                -1,
            ))
        }
    }
}

pub trait EntryBufferExtManual: 'static {
    /// Deletes a sequence of characters from the buffer.
    ///
    /// `n_chars` characters are deleted starting at `position`.
    /// If `n_chars` is negative, then all characters until the
    /// end of the text are deleted.
    ///
    /// If `position` or `n_chars` are out of bounds, then they
    /// are coerced to sane values.
    ///
    /// Note that the positions are specified in characters,
    /// not bytes.
    /// ## `position`
    /// position at which to delete text
    /// ## `n_chars`
    /// number of characters to delete
    ///
    /// # Returns
    ///
    /// The number of characters deleted.
    #[doc(alias = "gtk_entry_buffer_delete_text")]
    fn delete_text(&self, position: u16, n_chars: Option<u16>) -> u16;

    /// Retrieves the length in bytes of the buffer.
    ///
    /// See [``EntryBufferExtManual::length()``][crate::prelude::`EntryBufferExtManual::length()`].
    ///
    /// # Returns
    ///
    /// The byte length of the buffer.
    #[doc(alias = "gtk_entry_buffer_get_bytes")]
    #[doc(alias = "get_bytes")]
    fn bytes(&self) -> usize;

    /// Retrieves the length in characters of the buffer.
    ///
    /// # Returns
    ///
    /// The number of characters in the buffer.
    #[doc(alias = "gtk_entry_buffer_get_length")]
    #[doc(alias = "get_length")]
    fn length(&self) -> u16;

    /// Retrieves the maximum allowed length of the text in `self`.
    ///
    /// # Returns
    ///
    /// the maximum allowed number of characters
    ///  in [`EntryBuffer`][crate::EntryBuffer], or 0 if there is no maximum.
    #[doc(alias = "gtk_entry_buffer_get_max_length")]
    #[doc(alias = "get_max_length")]
    fn max_length(&self) -> Option<u16>;

    /// Retrieves the contents of the buffer.
    ///
    /// The memory pointer returned by this call will not change
    /// unless this object emits a signal, or is finalized.
    ///
    /// # Returns
    ///
    /// a pointer to the contents of the widget as a
    ///  string. This string points to internally allocated storage
    ///  in the buffer and must not be freed, modified or stored.
    #[doc(alias = "gtk_entry_buffer_get_text")]
    #[doc(alias = "get_text")]
    fn text(&self) -> String;

    /// Inserts `n_chars` characters of `chars` into the contents of the
    /// buffer, at position `position`.
    ///
    /// If `n_chars` is negative, then characters from chars will be inserted
    /// until a null-terminator is found. If `position` or `n_chars` are out of
    /// bounds, or the maximum buffer text length is exceeded, then they are
    /// coerced to sane values.
    ///
    /// Note that the position and length are in characters, not in bytes.
    /// ## `position`
    /// the position at which to insert text.
    /// ## `chars`
    /// the text to insert into the buffer.
    /// ## `n_chars`
    /// the length of the text in characters, or -1
    ///
    /// # Returns
    ///
    /// The number of characters actually inserted.
    #[doc(alias = "gtk_entry_buffer_insert_text")]
    fn insert_text(&self, position: u16, chars: &str) -> u16;

    /// Sets the maximum allowed length of the contents of the buffer.
    ///
    /// If the current contents are longer than the given length, then
    /// they will be truncated to fit.
    /// ## `max_length`
    /// the maximum length of the entry buffer, or 0 for no maximum.
    ///  (other than the maximum length of entries.) The value passed in will
    ///  be clamped to the range 0-65536.
    #[doc(alias = "gtk_entry_buffer_set_max_length")]
    fn set_max_length(&self, max_length: Option<u16>);

    /// Sets the text in the buffer.
    ///
    /// This is roughly equivalent to calling
    /// [``EntryBufferExtManual::delete_text()``][crate::prelude::`EntryBufferExtManual::delete_text()`] and
    /// [``EntryBufferExtManual::insert_text()``][crate::prelude::`EntryBufferExtManual::insert_text()`].
    ///
    /// Note that `n_chars` is in characters, not in bytes.
    /// ## `chars`
    /// the new text
    /// ## `n_chars`
    /// the number of characters in `text`, or -1
    #[doc(alias = "gtk_entry_buffer_set_text")]
    fn set_text(&self, chars: &str);
}

macro_rules! to_u16 {
    ($e:expr) => (
        {
            let x = $e;
            assert!(x as usize <= u16::max_value() as usize,
                "Unexpected value exceeding `u16` range");
            x as u16
        }
    )
}

impl<O: IsA<EntryBuffer>> EntryBufferExtManual for O {
    fn delete_text(&self, position: u16, n_chars: Option<u16>) -> u16 {
        unsafe {
            to_u16!(ffi::gtk_entry_buffer_delete_text(
                self.as_ref().to_glib_none().0,
                position as c_uint,
                n_chars.map(|n| n as c_int).unwrap_or(-1)
            ))
        }
    }

    fn bytes(&self) -> usize {
        unsafe { ffi::gtk_entry_buffer_get_bytes(self.as_ref().to_glib_none().0) as usize }
    }

    fn length(&self) -> u16 {
        unsafe {
            to_u16!(ffi::gtk_entry_buffer_get_length(
                self.as_ref().to_glib_none().0
            ))
        }
    }

    fn max_length(&self) -> Option<u16> {
        unsafe {
            match ffi::gtk_entry_buffer_get_max_length(self.as_ref().to_glib_none().0) {
                0 => None,
                x => Some(to_u16!(x)),
            }
        }
    }

    fn text(&self) -> String {
        unsafe {
            from_glib_none(ffi::gtk_entry_buffer_get_text(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    fn insert_text(&self, position: u16, chars: &str) -> u16 {
        unsafe {
            to_u16!(ffi::gtk_entry_buffer_insert_text(
                self.as_ref().to_glib_none().0,
                position as c_uint,
                chars.to_glib_none().0,
                -1
            ))
        }
    }

    fn set_max_length(&self, max_length: Option<u16>) {
        unsafe {
            assert_ne!(max_length, Some(0), "Zero maximum length not supported");
            ffi::gtk_entry_buffer_set_max_length(
                self.as_ref().to_glib_none().0,
                max_length.unwrap_or(0) as c_int,
            );
        }
    }

    fn set_text(&self, chars: &str) {
        unsafe {
            ffi::gtk_entry_buffer_set_text(
                self.as_ref().to_glib_none().0,
                chars.to_glib_none().0,
                -1,
            );
        }
    }
}