#[doc(hidden)]
#[macro_export]
macro_rules! query_def_type {
    (($type:ty)) => {
        $type
    };
    ('dyn ($type:ty)) => {
        $type
    };
    ('vec ($type:ty)) => {
        ::std::vec::Vec<$type>
    };
    ('map ($key:ty, $value:ty)) => {
        ::std::collections::HashMap<$key, $value>
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! query_def_field {
    (@dyn $type:ty) => {
        Option<<$type as $crate::DynamicQuery>::Definition>
    };
    (($type:ty)) => {
        bool
    };
    ('dyn ($type:ty)) => {
        $crate::query_def_field!(@dyn $type)
    };
    ('vec ($type:ty)) => {
        $crate::query_def_field!(@dyn $type)
    };
    ('map ($key:ty, $value:ty)) => {
        $crate::query_def_field!(@dyn $value)
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! query_def_filter {
    // note about this: 'dyn is implied for 'vec and 'map because if the type is not 'dyn, then the
    // special handling is not necessary in the first place (i.e. you can just do `(Vec<Type>)`
    // instead of `'vec (Type)`.
    ($query:expr, $value:ident, 'vec ($_type:path)) => {
        match $query {
            Some(query) => {
                if let Some(ref mut value) = $value {
                    for value in value.iter_mut() {
                        value.filter_ref(&query);
                    }
                }
            }
            None => {
                *$value = None;
            }
        }
    };
    ($query:expr, $value:ident, 'map ($_key:path, $_value:path)) => {
        match $query {
            Some(query) => {
                if let Some(ref mut value) = $value {
                    for (_, value) in value.iter_mut() {
                        value.filter_ref(&query);
                    }
                }
            }
            None => {
                *$value = None;
            }
        }
    };
    ($query:expr, $value:ident, 'dyn ($($_type:tt)+)) => {
        if let Some(ref mut value) = $value {
            if let Some(ref query) = $query {
                value.filter_ref(&query);
            }
        }
    };
    ($query:expr, $value:ident, ($($_type:tt)+)) => {
        if !*$query {
            *$value = None;
        }
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! query_def_internal_struct {
    (
        $( #[$meta:meta] )*
        $vis:vis $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$field_meta:meta] )*
                $field:ident: $( $qualifier:lifetime )? ($( $type:tt )+)
            ),+
        }
    ) => {
        #[derive(Debug, Clone)]
        $( #[$meta] )*
        $vis struct $data {
            $(
                $( #[$field_meta] )*
                pub $field: Option<$crate::query_def_type!($( $qualifier )? ($( $type )+))>
            ),+
        }

        $crate::paste::paste! {
            #[derive(Debug, Clone, Copy, Default)]
            $( $( #[$def_meta] )+ )?
            $vis struct [<$data Def>] {
                $( pub $field: $crate::query_def_field!($( $qualifier )? ($( $type )+)) ),+
            }
        }

        impl $crate::DynamicQuery for $data {
            type Definition = $crate::paste::paste! { [<$data Def>] };

            fn filter_ref(&mut self, def: &Self::Definition) {
                $(
                    let query = &def.$field;
                    let value = &mut self.$field;
                    $crate::query_def_filter!(query, value, $( $qualifier )? ($( $type )+));
                )+
            }
        }
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! query_def_internal_enum_variant_def {
    (
        $( #[$variant_def_meta:meta] )*
        $vis:vis $name:ident
    ) => {
        #[derive(Debug, Clone, Copy, Default)]
        $( #[$variant_def_meta] )*
        $vis struct $name;
    };
    (
        $( #[$variant_def_meta:meta] )*
        $vis:vis $name:ident {
            $( $field:ident$((
                $( #[$variant_def_field_meta:meta] )+
            ))?: $( $qualifier:lifetime )? ($( $type:tt )+) ),+
        }
    ) => {
        #[derive(Debug, Clone, Copy, Default)]
        $( #[$variant_def_meta] )*
        $vis struct $name {
            $(
                $( $( #[$variant_def_field_meta] )+ )?
                pub $field: $crate::query_def_field!($( $qualifier )? ($( $type )+))
            ),+
        }
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! query_def_internal_enum {
    (
        $( #[$meta:meta] )*
        $vis:vis $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$variant_meta:meta] )*
                $variant:ident$((
                    $( #[$variant_def_meta:meta] )+
                ))? $({
                    $(
                        $( #[$field_meta:meta] )*
                        $field:ident$((
                            $( #[$variant_def_field_meta:meta] )+
                        ))?: $( $qualifier:lifetime )? ($( $type:tt )+)
                    ),+
                })?
            ),+
        }
    ) => {
        #[derive(Debug, Clone)]
        $( #[$meta] )*
        $vis enum $data {
            $(
                $( #[$variant_meta] )*
                $variant $({
                    $(
                        $( #[$field_meta] )*
                        $field: Option<$crate::query_def_type!($( $qualifier )? ($( $type )+))>
                    ),*
                })?
            ),+
        }

        $crate::paste::paste! {
            #[derive(Debug, Clone, Copy, Default)]
            $( $( #[$def_meta] )+ )?
            $vis struct [<$data Def>] {
                $( pub [<$variant:snake:lower>]: [<$data Def Variant $variant>] ),+
            }
        }

//        $crate::paste::paste! {
//            impl [<$data Def>] {
//                $(
//                    pub type $variant = [<$data Def Variant $variant>];
//                )+
//            }
//        }

        $crate::paste::paste! {
            $(
                $crate::query_def_internal_enum_variant_def! {
                    $( $( #[$variant_def_meta] )+ )?
                    $vis [<$data Def Variant $variant>] $({
                        $( $field$((
                            $( #[$variant_def_field_meta] )+
                        ))?: $( $qualifier )? ($( $type )+) ),+
                    })?
                }
            )+
        }

        impl $crate::DynamicQuery for $data {
            type Definition = $crate::paste::paste! { [<$data Def>] };

            fn filter_ref(&mut self, def: &Self::Definition) {
                match self {
                    $(
                        Self::$variant $({ $( ref mut $field ),* })? => {
                            $($(
                                let query = &$crate::paste::paste! { &def.[<$variant:snake:lower>] }.$field;
                                $crate::query_def_filter!(query, $field, $( $qualifier )? ($( $type )+));
                            )*)?
                        }
                    )+
                }
            }
        }
    };
}

#[cfg(not(feature = "serde"))]
#[doc(hidden)]
#[macro_export]
macro_rules! query_def_0 {
    (
        $( #[$meta:meta] )*
        $vis:vis struct $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$field_meta:meta] )*
                $field:ident: $( $qualifier:lifetime )? ($( $type:tt )+)
            ),+

            $(,)?
        }
    ) => {
        $crate::query_def_internal_struct! {
            $( #[$meta] )*
            $vis $data$((
                $( #[$def_meta] )+
            ))? {
                $(
                    $( #[$field_meta] )*
                    $field: $( $qualifier )? ($( $type )+)
                ),+
            }
        }
    };
    (
        $( #[$meta:meta] )*
        $vis:vis enum $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$variant_meta:meta] )*
                $variant:ident$((
                    $( #[$variant_def_meta:meta] )+
                ))? $({
                    $(
                        $( #[$field_meta:meta] )*
                        $field:ident: $( $qualifier:lifetime )? ($( $type:tt )+)
                    ),+

                    $(,)?
                })?
            ),+

            $(,)?
        }
    ) => {
        $crate::query_def_internal_enum! {
            $( #[$meta] )*
            $vis $data$((
                $( #[$def_meta] )+
            ))? {
                $(
                    $( #[$variant_meta] )*
                    $variant$((
                        $( #[$variant_def_meta] )?
                    ))? $({
                        $(
                            $( #[$field_meta] )*
                            $field: $( $qualifier )? ($( $type )+)
                        ),+
                    })?
                ),+
            }
        }
    };
}

#[cfg(feature = "serde")]
#[doc(hidden)]
#[macro_export]
macro_rules! query_def_0 {
    (
        $( #[$meta:meta] )*
        $vis:vis struct $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$field_meta:meta] )*
                $field:ident: $( $qualifier:lifetime )? ($( $type:tt )+)
            ),+

            $(,)?
        }
    ) => {
        $crate::query_def_internal_struct! {
            #[derive($crate::serde::Serialize, $crate::serde::Deserialize)]
            $( #[$meta] )*
            $vis $data(
                #[derive($crate::serde::Serialize, $crate::serde::Deserialize)]
                #[serde(default)]
                $( $( #[$def_meta] )+ )?
            ) {
                $(
                    #[serde(skip_serializing_if = "Option::is_none")]
                    $( #[$field_meta] )*
                    $field: $( $qualifier )? ($( $type )+)
                ),+
            }
        }
    };
    (
        $( #[$meta:meta] )*
        $vis:vis enum $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $(
                $( #[$variant_meta:meta] )*
                $variant:ident$((
                    $( #[$variant_def_meta:meta] )+
                ))? $({
                    $(
                        $( #[$field_meta:meta] )*
                        $field:ident: $( $qualifier:lifetime )? ($( $type:tt )+)
                    ),+

                    $(,)?
                })?
            ),+

            $(,)?
        }
    ) => {
        $crate::query_def_internal_enum! {
            #[derive($crate::serde::Serialize, $crate::serde::Deserialize)]
            $( #[$meta] )*
            $vis $data(
                #[derive($crate::serde::Serialize, $crate::serde::Deserialize)]
                #[serde(default)]
                $( $( #[$def_meta] )+ )?
            ) {
                $(
                    $( #[$variant_meta] )*
                    $variant(
                        #[derive($crate::serde::Serialize, $crate::serde::Deserialize)]
                        $( $( #[$variant_def_meta] )+ )?
                    ) $({
                        $(
                            #[serde(skip_serializing_if = "Option::is_none")]
                            $( #[$field_meta] )*
                            $field(
                                #[serde(default)]
                            ): $( $qualifier )? ($( $type )+)
                        ),+
                    })?
                ),+
            }
        }
    };
}

/// Defines a dynamic query structure.
///
/// See the crate documentation for details.
#[macro_export]
macro_rules! query_def {
    ($(
        $( #[$meta:meta] )*
        $vis:vis $type:ident $data:ident$((
            $( #[$def_meta:meta] )+
        ))? {
            $($body:tt)+
        }
    )*) => {
        $($crate::query_def_0! {
            $( #[$meta] )*
            $vis $type $data$((
                $( #[$def_meta] )+
            ))? {
                $($body)+
            }
        })*
    };
}