ext_php_rs/types/

array.rs

//! Represents an array in PHP. As all arrays in PHP are associative arrays,
//! they are represented by hash tables.

use std::{
    collections::HashMap,
    convert::{TryFrom, TryInto},
    ffi::CString,
    fmt::{Debug, Display},
    iter::FromIterator,
    ptr,
    str::FromStr,
};

use crate::{
    boxed::{ZBox, ZBoxable},
    convert::{FromZval, IntoZval},
    error::{Error, Result},
    ffi::zend_ulong,
    ffi::{
        _zend_new_array, zend_array_count, zend_array_destroy, zend_array_dup, zend_hash_clean,
        zend_hash_get_current_data_ex, zend_hash_get_current_key_type_ex,
        zend_hash_get_current_key_zval_ex, zend_hash_index_del, zend_hash_index_find,
        zend_hash_index_update, zend_hash_move_backwards_ex, zend_hash_move_forward_ex,
        zend_hash_next_index_insert, zend_hash_str_del, zend_hash_str_find, zend_hash_str_update,
        HashPosition, HT_MIN_SIZE,
    },
    flags::DataType,
    types::Zval,
};

/// A PHP hashtable.
///
/// In PHP, arrays are represented as hashtables. This allows you to push values
/// onto the end of the array like a vector, while also allowing you to insert
/// at arbitrary string key indexes.
///
/// A PHP hashtable stores values as [`Zval`]s. This allows you to insert
/// different types into the same hashtable. Types must implement [`IntoZval`]
/// to be able to be inserted into the hashtable.
///
/// # Examples
///
/// ```no_run
/// use ext_php_rs::types::ZendHashTable;
///
/// let mut ht = ZendHashTable::new();
/// ht.push(1);
/// ht.push("Hello, world!");
/// ht.insert("Like", "Hashtable");
///
/// assert_eq!(ht.len(), 3);
/// assert_eq!(ht.get_index(0).and_then(|zv| zv.long()), Some(1));
/// ```
pub type ZendHashTable = crate::ffi::HashTable;

// Clippy complains about there being no `is_empty` function when implementing
// on the alias `ZendStr` :( <https://github.com/rust-lang/rust-clippy/issues/7702>
#[allow(clippy::len_without_is_empty)]
impl ZendHashTable {
    /// Creates a new, empty, PHP hashtable, returned inside a [`ZBox`].
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let ht = ZendHashTable::new();
    /// ```
    ///
    /// # Panics
    ///
    /// Panics if memory for the hashtable could not be allocated.
    #[must_use]
    pub fn new() -> ZBox<Self> {
        Self::with_capacity(HT_MIN_SIZE)
    }

    /// Creates a new, empty, PHP hashtable with an initial size, returned
    /// inside a [`ZBox`].
    ///
    /// # Parameters
    ///
    /// * `size` - The size to initialize the array with.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let ht = ZendHashTable::with_capacity(10);
    /// ```
    ///
    /// # Panics
    ///
    /// Panics if memory for the hashtable could not be allocated.
    #[must_use]
    pub fn with_capacity(size: u32) -> ZBox<Self> {
        unsafe {
            // SAFETY: PHP allocator handles the creation of the array.
            #[allow(clippy::used_underscore_items)]
            let ptr = _zend_new_array(size);

            // SAFETY: `as_mut()` checks if the pointer is null, and panics if it is not.
            ZBox::from_raw(
                ptr.as_mut()
                    .expect("Failed to allocate memory for hashtable"),
            )
        }
    }

    /// Returns the current number of elements in the array.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push(1);
    /// ht.push("Hello, world");
    ///
    /// assert_eq!(ht.len(), 2);
    /// ```
    #[must_use]
    pub fn len(&self) -> usize {
        unsafe { zend_array_count(ptr::from_ref(self).cast_mut()) as usize }
    }

    /// Returns whether the hash table is empty.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// assert_eq!(ht.is_empty(), true);
    ///
    /// ht.push(1);
    /// ht.push("Hello, world");
    ///
    /// assert_eq!(ht.is_empty(), false);
    /// ```
    #[must_use]
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Clears the hash table, removing all values.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert("test", "hello world");
    /// assert_eq!(ht.is_empty(), false);
    ///
    /// ht.clear();
    /// assert_eq!(ht.is_empty(), true);
    /// ```
    pub fn clear(&mut self) {
        unsafe { zend_hash_clean(self) }
    }

    /// Attempts to retrieve a value from the hash table with a string key.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to search for in the hash table.
    ///
    /// # Returns
    ///
    /// * `Some(&Zval)` - A reference to the zval at the position in the hash
    ///   table.
    /// * `None` - No value at the given position was found.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert("test", "hello world");
    /// assert_eq!(ht.get("test").and_then(|zv| zv.str()), Some("hello world"));
    /// ```
    #[must_use]
    pub fn get<'a, K>(&self, key: K) -> Option<&Zval>
    where
        K: Into<ArrayKey<'a>>,
    {
        match key.into() {
            ArrayKey::Long(index) => unsafe {
                #[allow(clippy::cast_sign_loss)]
                zend_hash_index_find(self, index as zend_ulong).as_ref()
            },
            ArrayKey::String(key) => {
                if let Ok(index) = i64::from_str(key.as_str()) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_find(self, index as zend_ulong).as_ref()
                    }
                } else {
                    unsafe {
                        zend_hash_str_find(
                            self,
                            CString::new(key.as_str()).ok()?.as_ptr(),
                            key.len() as _,
                        )
                        .as_ref()
                    }
                }
            }
            ArrayKey::Str(key) => {
                if let Ok(index) = i64::from_str(key) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_find(self, index as zend_ulong).as_ref()
                    }
                } else {
                    unsafe {
                        zend_hash_str_find(self, CString::new(key).ok()?.as_ptr(), key.len() as _)
                            .as_ref()
                    }
                }
            }
        }
    }

    /// Attempts to retrieve a value from the hash table with a string key.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to search for in the hash table.
    ///
    /// # Returns
    ///
    /// * `Some(&Zval)` - A reference to the zval at the position in the hash
    ///   table.
    /// * `None` - No value at the given position was found.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert("test", "hello world");
    /// assert_eq!(ht.get("test").and_then(|zv| zv.str()), Some("hello world"));
    /// ```
    // TODO: Verify if this is safe to use, as it allows mutating the
    // hashtable while only having a reference to it. #461
    #[allow(clippy::mut_from_ref)]
    #[must_use]
    pub fn get_mut<'a, K>(&self, key: K) -> Option<&mut Zval>
    where
        K: Into<ArrayKey<'a>>,
    {
        match key.into() {
            ArrayKey::Long(index) => unsafe {
                #[allow(clippy::cast_sign_loss)]
                zend_hash_index_find(self, index as zend_ulong).as_mut()
            },
            ArrayKey::String(key) => {
                if let Ok(index) = i64::from_str(key.as_str()) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_find(self, index as zend_ulong).as_mut()
                    }
                } else {
                    unsafe {
                        zend_hash_str_find(
                            self,
                            CString::new(key.as_str()).ok()?.as_ptr(),
                            key.len() as _,
                        )
                        .as_mut()
                    }
                }
            }
            ArrayKey::Str(key) => {
                if let Ok(index) = i64::from_str(key) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_find(self, index as zend_ulong).as_mut()
                    }
                } else {
                    unsafe {
                        zend_hash_str_find(self, CString::new(key).ok()?.as_ptr(), key.len() as _)
                            .as_mut()
                    }
                }
            }
        }
    }

    /// Attempts to retrieve a value from the hash table with an index.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to search for in the hash table.
    ///
    /// # Returns
    ///
    /// * `Some(&Zval)` - A reference to the zval at the position in the hash
    ///   table.
    /// * `None` - No value at the given position was found.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push(100);
    /// assert_eq!(ht.get_index(0).and_then(|zv| zv.long()), Some(100));
    /// ```
    #[must_use]
    pub fn get_index(&self, key: i64) -> Option<&Zval> {
        #[allow(clippy::cast_sign_loss)]
        unsafe {
            zend_hash_index_find(self, key as zend_ulong).as_ref()
        }
    }

    /// Attempts to retrieve a value from the hash table with an index.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to search for in the hash table.
    ///
    /// # Returns
    ///
    /// * `Some(&Zval)` - A reference to the zval at the position in the hash
    ///   table.
    /// * `None` - No value at the given position was found.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push(100);
    /// assert_eq!(ht.get_index(0).and_then(|zv| zv.long()), Some(100));
    /// ```
    // TODO: Verify if this is safe to use, as it allows mutating the
    // hashtable while only having a reference to it. #461
    #[allow(clippy::mut_from_ref)]
    #[must_use]
    pub fn get_index_mut(&self, key: i64) -> Option<&mut Zval> {
        unsafe {
            #[allow(clippy::cast_sign_loss)]
            zend_hash_index_find(self, key as zend_ulong).as_mut()
        }
    }

    /// Attempts to remove a value from the hash table with a string key.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to remove from the hash table.
    ///
    /// # Returns
    ///
    /// * `Some(())` - Key was successfully removed.
    /// * `None` - No key was removed, did not exist.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert("test", "hello world");
    /// assert_eq!(ht.len(), 1);
    ///
    /// ht.remove("test");
    /// assert_eq!(ht.len(), 0);
    /// ```
    pub fn remove<'a, K>(&mut self, key: K) -> Option<()>
    where
        K: Into<ArrayKey<'a>>,
    {
        let result = match key.into() {
            ArrayKey::Long(index) => unsafe {
                #[allow(clippy::cast_sign_loss)]
                zend_hash_index_del(self, index as zend_ulong)
            },
            ArrayKey::String(key) => {
                if let Ok(index) = i64::from_str(key.as_str()) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_del(self, index as zend_ulong)
                    }
                } else {
                    unsafe {
                        zend_hash_str_del(
                            self,
                            CString::new(key.as_str()).ok()?.as_ptr(),
                            key.len() as _,
                        )
                    }
                }
            }
            ArrayKey::Str(key) => {
                if let Ok(index) = i64::from_str(key) {
                    #[allow(clippy::cast_sign_loss)]
                    unsafe {
                        zend_hash_index_del(self, index as zend_ulong)
                    }
                } else {
                    unsafe {
                        zend_hash_str_del(self, CString::new(key).ok()?.as_ptr(), key.len() as _)
                    }
                }
            }
        };

        if result < 0 {
            None
        } else {
            Some(())
        }
    }

    /// Attempts to remove a value from the hash table with a string key.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to remove from the hash table.
    ///
    /// # Returns
    ///
    /// * `Ok(())` - Key was successfully removed.
    /// * `None` - No key was removed, did not exist.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push("hello");
    /// assert_eq!(ht.len(), 1);
    ///
    /// ht.remove_index(0);
    /// assert_eq!(ht.len(), 0);
    /// ```
    pub fn remove_index(&mut self, key: i64) -> Option<()> {
        let result = unsafe {
            #[allow(clippy::cast_sign_loss)]
            zend_hash_index_del(self, key as zend_ulong)
        };

        if result < 0 {
            None
        } else {
            Some(())
        }
    }

    /// Attempts to insert an item into the hash table, or update if the key
    /// already exists. Returns nothing in a result if successful.
    ///
    /// # Parameters
    ///
    /// * `key` - The key to insert the value at in the hash table.
    /// * `value` - The value to insert into the hash table.
    ///
    /// # Returns
    ///
    /// Returns nothing in a result on success.
    ///
    /// # Errors
    ///
    /// Returns an error if the key could not be converted into a [`CString`],
    /// or converting the value into a [`Zval`] failed.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert("a", "A");
    /// ht.insert("b", "B");
    /// ht.insert("c", "C");
    /// assert_eq!(ht.len(), 3);
    /// ```
    pub fn insert<'a, K, V>(&mut self, key: K, val: V) -> Result<()>
    where
        K: Into<ArrayKey<'a>>,
        V: IntoZval,
    {
        let mut val = val.into_zval(false)?;
        match key.into() {
            ArrayKey::Long(index) => {
                unsafe {
                    #[allow(clippy::cast_sign_loss)]
                    zend_hash_index_update(self, index as zend_ulong, &raw mut val)
                };
            }
            ArrayKey::String(key) => {
                if let Ok(index) = i64::from_str(&key) {
                    unsafe {
                        #[allow(clippy::cast_sign_loss)]
                        zend_hash_index_update(self, index as zend_ulong, &raw mut val)
                    };
                } else {
                    unsafe {
                        zend_hash_str_update(
                            self,
                            CString::new(key.as_str())?.as_ptr(),
                            key.len(),
                            &raw mut val,
                        )
                    };
                }
            }
            ArrayKey::Str(key) => {
                if let Ok(index) = i64::from_str(key) {
                    unsafe {
                        #[allow(clippy::cast_sign_loss)]
                        zend_hash_index_update(self, index as zend_ulong, &raw mut val)
                    };
                } else {
                    unsafe {
                        zend_hash_str_update(
                            self,
                            CString::new(key)?.as_ptr(),
                            key.len(),
                            &raw mut val,
                        )
                    };
                }
            }
        }
        val.release();
        Ok(())
    }

    /// Inserts an item into the hash table at a specified index, or updates if
    /// the key already exists. Returns nothing in a result if successful.
    ///
    /// # Parameters
    ///
    /// * `key` - The index at which the value should be inserted.
    /// * `val` - The value to insert into the hash table.
    ///
    /// # Returns
    ///
    /// Returns nothing in a result on success.
    ///
    /// # Errors
    ///
    /// Returns an error if converting the value into a [`Zval`] failed.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.insert_at_index(0, "A");
    /// ht.insert_at_index(5, "B");
    /// ht.insert_at_index(0, "C"); // notice overriding index 0
    /// assert_eq!(ht.len(), 2);
    /// ```
    pub fn insert_at_index<V>(&mut self, key: i64, val: V) -> Result<()>
    where
        V: IntoZval,
    {
        let mut val = val.into_zval(false)?;
        unsafe {
            #[allow(clippy::cast_sign_loss)]
            zend_hash_index_update(self, key as zend_ulong, &raw mut val)
        };
        val.release();
        Ok(())
    }

    /// Pushes an item onto the end of the hash table. Returns a result
    /// containing nothing if the element was successfully inserted.
    ///
    /// # Parameters
    ///
    /// * `val` - The value to insert into the hash table.
    ///
    /// # Returns
    ///
    /// Returns nothing in a result on success.
    ///
    /// # Errors
    ///
    /// Returns an error if converting the value into a [`Zval`] failed.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push("a");
    /// ht.push("b");
    /// ht.push("c");
    /// assert_eq!(ht.len(), 3);
    /// ```
    pub fn push<V>(&mut self, val: V) -> Result<()>
    where
        V: IntoZval,
    {
        let mut val = val.into_zval(false)?;
        unsafe { zend_hash_next_index_insert(self, &raw mut val) };
        val.release();

        Ok(())
    }

    /// Checks if the hashtable only contains numerical keys.
    ///
    /// # Returns
    ///
    /// True if all keys on the hashtable are numerical.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push(0);
    /// ht.push(3);
    /// ht.push(9);
    /// assert!(ht.has_numerical_keys());
    ///
    /// ht.insert("obviously not numerical", 10);
    /// assert!(!ht.has_numerical_keys());
    /// ```
    #[must_use]
    pub fn has_numerical_keys(&self) -> bool {
        !self.into_iter().any(|(k, _)| !k.is_long())
    }

    /// Checks if the hashtable has numerical, sequential keys.
    ///
    /// # Returns
    ///
    /// True if all keys on the hashtable are numerical and are in sequential
    /// order (i.e. starting at 0 and not skipping any keys).
    ///
    /// # Panics
    ///
    /// Panics if the number of elements in the hashtable exceeds `i64::MAX`.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// ht.push(0);
    /// ht.push(3);
    /// ht.push(9);
    /// assert!(ht.has_sequential_keys());
    ///
    /// ht.insert_at_index(90, 10);
    /// assert!(!ht.has_sequential_keys());
    /// ```
    #[must_use]
    pub fn has_sequential_keys(&self) -> bool {
        !self
            .into_iter()
            .enumerate()
            .any(|(i, (k, _))| ArrayKey::Long(i64::try_from(i).expect("Integer overflow")) != k)
    }

    /// Returns an iterator over the values contained inside the hashtable, as
    /// if it was a set or list.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// for val in ht.values() {
    ///     dbg!(val);
    /// }
    #[inline]
    #[must_use]
    pub fn values(&self) -> Values<'_> {
        Values::new(self)
    }

    /// Returns an iterator over the key(s) and value contained inside the
    /// hashtable.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::{ZendHashTable, ArrayKey};
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// for (key, val) in ht.iter() {
    ///     match &key {
    ///         ArrayKey::Long(index) => {
    ///         }
    ///         ArrayKey::String(key) => {
    ///         }
    ///         ArrayKey::Str(key) => {
    ///         }
    ///     }
    ///     dbg!(key, val);
    /// }
    #[inline]
    #[must_use]
    pub fn iter(&self) -> Iter<'_> {
        self.into_iter()
    }
}

unsafe impl ZBoxable for ZendHashTable {
    fn free(&mut self) {
        // SAFETY: ZBox has immutable access to `self`.
        unsafe { zend_array_destroy(self) }
    }
}

impl Debug for ZendHashTable {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_map()
            .entries(self.into_iter().map(|(k, v)| (k.to_string(), v)))
            .finish()
    }
}

impl ToOwned for ZendHashTable {
    type Owned = ZBox<ZendHashTable>;

    fn to_owned(&self) -> Self::Owned {
        unsafe {
            // SAFETY: FFI call does not modify `self`, returns a new hashtable.
            let ptr = zend_array_dup(ptr::from_ref(self).cast_mut());

            // SAFETY: `as_mut()` checks if the pointer is null, and panics if it is not.
            ZBox::from_raw(
                ptr.as_mut()
                    .expect("Failed to allocate memory for hashtable"),
            )
        }
    }
}

/// Immutable iterator upon a reference to a hashtable.
pub struct Iter<'a> {
    ht: &'a ZendHashTable,
    current_num: i64,
    end_num: i64,
    pos: HashPosition,
    end_pos: HashPosition,
}

/// Represents the key of a PHP array, which can be either a long or a string.
#[derive(Debug, Clone, PartialEq)]
pub enum ArrayKey<'a> {
    /// A numerical key.
    /// In Zend API it's represented by `u64` (`zend_ulong`), so the value needs
    /// to be cast to `zend_ulong` before passing into Zend functions.
    Long(i64),
    /// A string key.
    String(String),
    /// A string key by reference.
    Str(&'a str),
}

impl From<String> for ArrayKey<'_> {
    fn from(value: String) -> Self {
        Self::String(value)
    }
}

impl ArrayKey<'_> {
    /// Check if the key is an integer.
    ///
    /// # Returns
    ///
    /// Returns true if the key is an integer, false otherwise.
    #[must_use]
    pub fn is_long(&self) -> bool {
        match self {
            ArrayKey::Long(_) => true,
            ArrayKey::String(_) | ArrayKey::Str(_) => false,
        }
    }
}

impl Display for ArrayKey<'_> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            ArrayKey::Long(key) => write!(f, "{key}"),
            ArrayKey::String(key) => write!(f, "{key}"),
            ArrayKey::Str(key) => write!(f, "{key}"),
        }
    }
}

impl<'a> From<&'a str> for ArrayKey<'a> {
    fn from(key: &'a str) -> ArrayKey<'a> {
        ArrayKey::Str(key)
    }
}

impl<'a> From<i64> for ArrayKey<'a> {
    fn from(index: i64) -> ArrayKey<'a> {
        ArrayKey::Long(index)
    }
}

impl<'a> FromZval<'a> for ArrayKey<'_> {
    const TYPE: DataType = DataType::String;

    fn from_zval(zval: &'a Zval) -> Option<Self> {
        if let Some(key) = zval.long() {
            return Some(ArrayKey::Long(key));
        }
        if let Some(key) = zval.string() {
            return Some(ArrayKey::String(key));
        }
        None
    }
}

impl<'a> Iter<'a> {
    /// Creates a new iterator over a hashtable.
    ///
    /// # Parameters
    ///
    /// * `ht` - The hashtable to iterate.
    pub fn new(ht: &'a ZendHashTable) -> Self {
        let end_num: i64 = ht
            .len()
            .try_into()
            .expect("Integer overflow in hashtable length");
        let end_pos = if ht.nNumOfElements > 0 {
            ht.nNumOfElements - 1
        } else {
            0
        };

        Self {
            ht,
            current_num: 0,
            end_num,
            pos: 0,
            end_pos,
        }
    }
}

impl<'a> IntoIterator for &'a ZendHashTable {
    type Item = (ArrayKey<'a>, &'a Zval);
    type IntoIter = Iter<'a>;

    /// Returns an iterator over the key(s) and value contained inside the
    /// hashtable.
    ///
    /// # Example
    ///
    /// ```no_run
    /// use ext_php_rs::types::ZendHashTable;
    ///
    /// let mut ht = ZendHashTable::new();
    ///
    /// for (key, val) in ht.iter() {
    /// //   ^ Index if inserted at an index.
    /// //        ^ Optional string key, if inserted like a hashtable.
    /// //             ^ Inserted value.
    ///
    ///     dbg!(key, val);
    /// }
    #[inline]
    fn into_iter(self) -> Self::IntoIter {
        Iter::new(self)
    }
}

impl<'a> Iterator for Iter<'a> {
    type Item = (ArrayKey<'a>, &'a Zval);

    fn next(&mut self) -> Option<Self::Item> {
        self.next_zval()
            .map(|(k, v)| (ArrayKey::from_zval(&k).expect("Invalid array key!"), v))
    }

    fn count(self) -> usize
    where
        Self: Sized,
    {
        self.ht.len()
    }
}

impl ExactSizeIterator for Iter<'_> {
    fn len(&self) -> usize {
        self.ht.len()
    }
}

impl DoubleEndedIterator for Iter<'_> {
    fn next_back(&mut self) -> Option<Self::Item> {
        if self.end_num <= self.current_num {
            return None;
        }

        let key_type = unsafe {
            zend_hash_get_current_key_type_ex(ptr::from_ref(self.ht).cast_mut(), &raw mut self.pos)
        };

        if key_type == -1 {
            return None;
        }

        let key = Zval::new();

        unsafe {
            zend_hash_get_current_key_zval_ex(
                ptr::from_ref(self.ht).cast_mut(),
                (&raw const key).cast_mut(),
                &raw mut self.end_pos,
            );
        }
        let value = unsafe {
            &*zend_hash_get_current_data_ex(
                ptr::from_ref(self.ht).cast_mut(),
                &raw mut self.end_pos,
            )
        };

        let key = match ArrayKey::from_zval(&key) {
            Some(key) => key,
            None => ArrayKey::Long(self.end_num),
        };

        unsafe {
            zend_hash_move_backwards_ex(ptr::from_ref(self.ht).cast_mut(), &raw mut self.end_pos)
        };
        self.end_num -= 1;

        Some((key, value))
    }
}

impl<'a> Iter<'a> {
    pub fn next_zval(&mut self) -> Option<(Zval, &'a Zval)> {
        if self.current_num >= self.end_num {
            return None;
        }

        let key_type = unsafe {
            zend_hash_get_current_key_type_ex(ptr::from_ref(self.ht).cast_mut(), &raw mut self.pos)
        };

        // Key type `-1` is ???
        // Key type `1` is string
        // Key type `2` is long
        // Key type `3` is null meaning the end of the array
        if key_type == -1 || key_type == 3 {
            return None;
        }

        let mut key = Zval::new();

        unsafe {
            zend_hash_get_current_key_zval_ex(
                ptr::from_ref(self.ht).cast_mut(),
                (&raw const key).cast_mut(),
                &raw mut self.pos,
            );
        }
        let value = unsafe {
            let val_ptr =
                zend_hash_get_current_data_ex(ptr::from_ref(self.ht).cast_mut(), &raw mut self.pos);

            if val_ptr.is_null() {
                return None;
            }

            &*val_ptr
        };

        if !key.is_long() && !key.is_string() {
            key.set_long(self.current_num);
        }

        unsafe { zend_hash_move_forward_ex(ptr::from_ref(self.ht).cast_mut(), &raw mut self.pos) };
        self.current_num += 1;

        Some((key, value))
    }
}

/// Immutable iterator which iterates over the values of the hashtable, as it
/// was a set or list.
pub struct Values<'a>(Iter<'a>);

impl<'a> Values<'a> {
    /// Creates a new iterator over a hashtables values.
    ///
    /// # Parameters
    ///
    /// * `ht` - The hashtable to iterate.
    pub fn new(ht: &'a ZendHashTable) -> Self {
        Self(Iter::new(ht))
    }
}

impl<'a> Iterator for Values<'a> {
    type Item = &'a Zval;

    fn next(&mut self) -> Option<Self::Item> {
        self.0.next().map(|(_, zval)| zval)
    }

    fn count(self) -> usize
    where
        Self: Sized,
    {
        self.0.count()
    }
}

impl ExactSizeIterator for Values<'_> {
    fn len(&self) -> usize {
        self.0.len()
    }
}

impl DoubleEndedIterator for Values<'_> {
    fn next_back(&mut self) -> Option<Self::Item> {
        self.0.next_back().map(|(_, zval)| zval)
    }
}

impl Default for ZBox<ZendHashTable> {
    fn default() -> Self {
        ZendHashTable::new()
    }
}

impl Clone for ZBox<ZendHashTable> {
    fn clone(&self) -> Self {
        (**self).to_owned()
    }
}

impl IntoZval for ZBox<ZendHashTable> {
    const TYPE: DataType = DataType::Array;
    const NULLABLE: bool = false;

    fn set_zval(self, zv: &mut Zval, _: bool) -> Result<()> {
        zv.set_hashtable(self);
        Ok(())
    }
}

impl<'a> FromZval<'a> for &'a ZendHashTable {
    const TYPE: DataType = DataType::Array;

    fn from_zval(zval: &'a Zval) -> Option<Self> {
        zval.array()
    }
}

///////////////////////////////////////////
// HashMap
///////////////////////////////////////////

// TODO: Generalize hasher
#[allow(clippy::implicit_hasher)]
impl<'a, V> TryFrom<&'a ZendHashTable> for HashMap<String, V>
where
    V: FromZval<'a>,
{
    type Error = Error;

    fn try_from(value: &'a ZendHashTable) -> Result<Self> {
        let mut hm = HashMap::with_capacity(value.len());

        for (key, val) in value {
            hm.insert(
                key.to_string(),
                V::from_zval(val).ok_or_else(|| Error::ZvalConversion(val.get_type()))?,
            );
        }

        Ok(hm)
    }
}

impl<K, V> TryFrom<HashMap<K, V>> for ZBox<ZendHashTable>
where
    K: AsRef<str>,
    V: IntoZval,
{
    type Error = Error;

    fn try_from(value: HashMap<K, V>) -> Result<Self> {
        let mut ht = ZendHashTable::with_capacity(
            value.len().try_into().map_err(|_| Error::IntegerOverflow)?,
        );

        for (k, v) in value {
            ht.insert(k.as_ref(), v)?;
        }

        Ok(ht)
    }
}

// TODO: Generalize hasher
#[allow(clippy::implicit_hasher)]
impl<K, V> IntoZval for HashMap<K, V>
where
    K: AsRef<str>,
    V: IntoZval,
{
    const TYPE: DataType = DataType::Array;
    const NULLABLE: bool = false;

    fn set_zval(self, zv: &mut Zval, _: bool) -> Result<()> {
        let arr = self.try_into()?;
        zv.set_hashtable(arr);
        Ok(())
    }
}

// TODO: Generalize hasher
#[allow(clippy::implicit_hasher)]
impl<'a, T> FromZval<'a> for HashMap<String, T>
where
    T: FromZval<'a>,
{
    const TYPE: DataType = DataType::Array;

    fn from_zval(zval: &'a Zval) -> Option<Self> {
        zval.array().and_then(|arr| arr.try_into().ok())
    }
}

///////////////////////////////////////////
// Vec
///////////////////////////////////////////

impl<'a, T> TryFrom<&'a ZendHashTable> for Vec<T>
where
    T: FromZval<'a>,
{
    type Error = Error;

    fn try_from(value: &'a ZendHashTable) -> Result<Self> {
        let mut vec = Vec::with_capacity(value.len());

        for (_, val) in value {
            vec.push(T::from_zval(val).ok_or_else(|| Error::ZvalConversion(val.get_type()))?);
        }

        Ok(vec)
    }
}

impl<T> TryFrom<Vec<T>> for ZBox<ZendHashTable>
where
    T: IntoZval,
{
    type Error = Error;

    fn try_from(value: Vec<T>) -> Result<Self> {
        let mut ht = ZendHashTable::with_capacity(
            value.len().try_into().map_err(|_| Error::IntegerOverflow)?,
        );

        for val in value {
            ht.push(val)?;
        }

        Ok(ht)
    }
}

impl<T> IntoZval for Vec<T>
where
    T: IntoZval,
{
    const TYPE: DataType = DataType::Array;
    const NULLABLE: bool = false;

    fn set_zval(self, zv: &mut Zval, _: bool) -> Result<()> {
        let arr = self.try_into()?;
        zv.set_hashtable(arr);
        Ok(())
    }
}

impl<'a, T> FromZval<'a> for Vec<T>
where
    T: FromZval<'a>,
{
    const TYPE: DataType = DataType::Array;

    fn from_zval(zval: &'a Zval) -> Option<Self> {
        zval.array().and_then(|arr| arr.try_into().ok())
    }
}

impl FromIterator<Zval> for ZBox<ZendHashTable> {
    fn from_iter<T: IntoIterator<Item = Zval>>(iter: T) -> Self {
        let mut ht = ZendHashTable::new();
        for item in iter {
            // Inserting a zval cannot fail, as `push` only returns `Err` if converting
            // `val` to a zval fails.
            let _ = ht.push(item);
        }
        ht
    }
}

impl FromIterator<(i64, Zval)> for ZBox<ZendHashTable> {
    fn from_iter<T: IntoIterator<Item = (i64, Zval)>>(iter: T) -> Self {
        let mut ht = ZendHashTable::new();
        for (key, val) in iter {
            // Inserting a zval cannot fail, as `push` only returns `Err` if converting
            // `val` to a zval fails.
            let _ = ht.insert_at_index(key, val);
        }
        ht
    }
}

impl<'a> FromIterator<(&'a str, Zval)> for ZBox<ZendHashTable> {
    fn from_iter<T: IntoIterator<Item = (&'a str, Zval)>>(iter: T) -> Self {
        let mut ht = ZendHashTable::new();
        for (key, val) in iter {
            // Inserting a zval cannot fail, as `push` only returns `Err` if converting
            // `val` to a zval fails.
            let _ = ht.insert(key, val);
        }
        ht
    }
}