structom 0.2.5

use std::{
	collections::HashMap,
	fmt::{self, Display, Formatter},
	hash::{self, Hash},
	ops::{Index, IndexMut},
	slice::SliceIndex,
	sync::LazyLock,
};

use chrono::{DateTime, TimeDelta, Utc};
use num_bigint::BigInt;

use crate::stringify::{StringifyOptions, str_key, stringify};

/// type representing a structom value.
///
/// `Value`s are wrappers that represent any structom value, builtin or user defined.
///
/// they can be created manually or from source or binary, manipulated or converted to native types, and stringified or serialized.
///
/// ## api
/// `Value` can be created through different forms
/// ```
/// // manually
/// Value::from(1) // => Uint(1)
///
/// // from source
/// parse("1", &ParseOptions::default(), &VoidProvider{}); // => Uint(1)
///
/// // from binary
/// decode(&[0, 16, 1], &VoidProvider{}); // => Uint(1)
/// ```
///
/// `Value` has different methods for manipulation its value.
/// ```
/// let value = Value::Uint(1);
///
/// // test type
/// value.is_uint(); // => true
///
/// // get ref to inner value
/// value.as_uint(); // => Some(1)
///
/// // compare inner value
/// value == 1; // => true
///
/// // index for array and map
/// Value::from(vec![1, 2, 3])[1] // => Uint(2)
/// ```
///
/// `Value` can be transformed into other forms.
/// ```
/// let value = Value::Uint(1);
///
/// // convert to native type
///	value.cast<u64>(); // => Ok(1)
///
/// // stringify into object notation
/// stringify(value, &StringifyOptions::default()); // => "1"
///
/// // encode into binary
/// encode(value); // => [0, 16, 1]
/// ```
///
/// ## representation
/// builtin types are represented through their respective variant.
///
/// structs are represented through the `Map` variant containing the struct fields.
///
/// enums are represented by the `UnitVar` case it is unit variant.       
/// else they are represented by a `Map` variant containing the fields, with a special key [`Key::enum_variant_key()`] storing the variant name.
///
/// for metadata wrapped types, they are represented by a `Map` variant containing the metadata with their values, with special keys: [`Key::has_meta_key()`] of value `true` and [`Key::inner_key()`] containing the wrapped value.
#[derive(Debug, Clone)]
pub enum Value {
	/// boolean value, types: `bool`.
	Bool(bool),
	/// signed integer value, types: `i8`, `i16`, `i32`, `i64` `vint`.
	Int(i64),
	/// unsigned integer value, types: `u8`, `u16`, `u32`, `u64` `vuint`.
	Uint(u64),
	/// big integer value, types: `bint`.
	BigInt(BigInt),
	/// floating point value, types: `f32`, `f64`
	Float(f64),
	/// string value, types: `str`.
	Str(String),
	/// instance value, types: `inst`, `instN`.
	Inst(DateTime<Utc>),
	/// duration value, types: `dur`.
	Dur(TimeDelta),
	/// uuid value, types: `uuid`.
	UUID([u8; 16]),
	/// array value, types: `arr`.
	Arr(Vec<Value>),
	/// map value, types: `map`, structs, enums with fields.
	Map(Box<HashMap<Key, Value>>),
	/// unit variant enum, types: `enum`.
	UnitVar(String),
}

/// a type used as [`Value::Map`] key.
///
/// `Key` is a subset of [`Value`] for types that can be used a keys for `Value::Map`.
///
/// it supports all the api supported by its underlaying variants, and can be converted from and into `Value`.
///
/// ## example
/// ```
/// let map = Value::Map(HashMap::new())
/// 	.insert(Key::from("some_key"), Value::Uint(1)); // => {"some_key": 1}
/// ```
#[derive(Debug, Clone, Hash, Eq)]
pub enum Key {
	/// boolean value, types: `bool`.
	Bool(bool),
	/// signed integer value, types: `i8`, `i16`, `i32`, `i64` `vint`.
	Int(i64),
	/// unsigned integer value, types: `u8`, `u16`, `u32`, `u64` `vuint`.
	Uint(u64),
	/// big integer value, types: `bint`.
	BigInt(BigInt),
	/// string value, types: `str`.
	Str(String),
	/// instance value, types: `inst`, `instN`.
	Inst(DateTime<Utc>),
	/// duration value, types: `dur`.
	Dur(TimeDelta),
	/// uuid value, types: `uuid`.
	UUID([u8; 16]),
}

impl Default for Value {
	fn default() -> Self {
		Value::Uint(0)
	}
}
impl Default for Key {
	fn default() -> Self {
		Key::Uint(0)
	}
}

pub static ENUM_VARIANT_KEY: LazyLock<Key> =
	LazyLock::new(|| Key::Str("$enum_variant".to_string()));
pub static HAS_META_KEY: LazyLock<Key> = LazyLock::new(|| Key::Str("$has_meta".to_string()));
pub static INNER_KEY: LazyLock<Key> = LazyLock::new(|| Key::Str("$value".to_string()));
impl Key {
	/// the enum variant key in an enum map
	pub fn enum_variant_key() -> &'static Key {
		&ENUM_VARIANT_KEY
	}
	/// the has metadata key in a metadata wrapped type
	pub fn has_meta_key() -> &'static Key {
		&HAS_META_KEY
	}
	/// the inner value key of a metadata wrapped type
	pub fn inner_key() -> &'static Key {
		&INNER_KEY
	}
}

macro_rules! is_impl {
	($enum:ident, $(($ty:ident, $met:ident)),+) => {
		$(pub fn $met(&self) -> bool {
			match self {
				$enum::$ty(_) => true,
				_ => false,
			}
		})+
	};
}

/// `is_T() -> bool`: whether the inner value is of type `T`.
impl Value {
	is_impl!(Value, (Bool, is_bool), (Uint, is_uint), (Int, is_int), (Str, is_str));
	is_impl!(Value, (BigInt, is_bigint), (Float, is_float), (Inst, is_inst), (Dur, is_dur));
	is_impl!(Value, (UUID, is_uuid), (Arr, is_array), (Map, is_map), (UnitVar, is_unit_variant));

	/// whether the inner value is an enum
	pub fn is_enum(&self) -> bool {
		match self {
			Value::UnitVar(_) => true,
			Value::Map(map) => map.contains_key(&ENUM_VARIANT_KEY),
			_ => false,
		}
	}
	/// whether the inner value is a metadata wrapped type
	pub fn has_meta(&self) -> bool {
		match self {
			Value::Map(map) => map.contains_key(&HAS_META_KEY),
			_ => false,
		}
	}
}

/// `is_T() -> bool`: whether the inner value is of type `T`.
impl Key {
	is_impl!(Key, (Bool, is_bool), (Uint, is_uint), (Int, is_int), (Str, is_str));
	is_impl!(Key, (BigInt, is_bigint), (Inst, is_inst), (Dur, is_dur), (UUID, is_uuid));
}

impl Value {
	/// convert `Value` into [`Key`]
	pub fn into_key(self) -> Option<Key> {
		self.try_into().ok()
	}
	/// get name of the wrapped enum variant, if not enum return `None`.
	pub fn enum_variant(&self) -> Option<&str> {
		match self {
			Value::UnitVar(str) => Some(str),
			Value::Map(map) => map.get(&ENUM_VARIANT_KEY)?.as_str(),
			_ => None,
		}
	}
	/// get the inner value of a metadata wrapped type, else return self.
	pub fn inner(&self) -> &Value {
		match &self {
			Value::Map(map) if map.contains_key(&HAS_META_KEY) => &map[&INNER_KEY],
			_ => self,
		}
	}
	/// get mut ref to the inner value of a metadata wrapped type, else return self.
	pub fn inner_mut(&mut self) -> &mut Value {
		if let Value::Map(map) = self {
			if map.contains_key(&HAS_META_KEY) {
				return map.get_mut(&INNER_KEY).unwrap();
			}
			panic!("actualy this doesnt work since of dark magic, if you can fix it, please do")
		}
		self
	}
	/// unwrap the inner value of a metadata wrapped type, else return self.
	pub fn into_inner(self) -> Value {
		match self {
			Value::Map(mut map) if map.contains_key(&HAS_META_KEY) => {
				map.remove(&INNER_KEY).unwrap()
			}
			_ => self,
		}
	}
}

impl TryFrom<Value> for Key {
	type Error = ();
	fn try_from(value: Value) -> Result<Self, Self::Error> {
		match value {
			Value::Bool(b) => Ok(Key::Bool(b)),
			Value::Int(i) => Ok(Key::Int(i)),
			Value::Uint(i) => Ok(Key::Uint(i)),
			Value::BigInt(i) => Ok(Key::BigInt(i)),
			Value::Str(s) => Ok(Key::Str(s)),
			Value::Inst(i) => Ok(Key::Inst(i)),
			Value::Dur(d) => Ok(Key::Dur(d)),
			Value::UUID(u) => Ok(Key::UUID(u)),
			_ => Err(()),
		}
	}
}
impl From<Key> for Value {
	fn from(key: Key) -> Self {
		match key {
			Key::Bool(b) => Value::Bool(b),
			Key::Int(i) => Value::Int(i),
			Key::Uint(i) => Value::Uint(i),
			Key::BigInt(i) => Value::BigInt(i),
			Key::Str(s) => Value::Str(s),
			Key::Inst(i) => Value::Inst(i),
			Key::Dur(d) => Value::Dur(d),
			Key::UUID(u) => Value::UUID(u),
		}
	}
}

macro_rules! from_impl {
	($enum:ident, $(($ty:ty, $var:ident)),+) => {
		$(impl From<$ty> for $enum {
			fn from(v: $ty) -> Self {
				$enum::$var(v)
			}
		})+
	};
	($enum:ident, $var:ident, $as:ident, [$($ty:ident),+]) => {
		$(impl From<$ty> for $enum {
			fn from(v: $ty) -> Self {
				$enum::$var(v as $as)
			}
		})+
	};
}

from_impl!(Value, (bool, Bool), (i64, Int), (u64, Uint), (f64, Float));
from_impl!(Value, (String, Str), (DateTime<Utc>, Inst), (TimeDelta, Dur));
from_impl!(Value, ([u8; 16], UUID), (BigInt, BigInt));

from_impl!(Value, Uint, u64, [u8, u16, u32, usize]);
from_impl!(Value, Int, i64, [i8, i16, i32, isize]);
from_impl!(Value, Float, f64, [f32]);

from_impl!(Key, (bool, Bool), (i64, Int), (u64, Uint), (String, Str), (BigInt, BigInt));
from_impl!(Key, (DateTime<Utc>, Inst), (TimeDelta, Dur), ([u8; 16], UUID));

from_impl!(Key, Uint, u64, [u8, u16, u32, usize]);
from_impl!(Key, Int, i64, [i8, i16, i32, isize]);

impl From<&str> for Value {
	fn from(s: &str) -> Self {
		Value::Str(s.to_string())
	}
}
impl From<&str> for Key {
	fn from(s: &str) -> Self {
		Key::Str(s.to_string())
	}
}

impl<T: Into<Value>> From<Vec<T>> for Value {
	fn from(v: Vec<T>) -> Self {
		Value::Arr(v.into_iter().map(|v| v.into()).collect())
	}
}
impl<K: Into<Key>, V: Into<Value>> From<HashMap<K, V>> for Value {
	fn from(m: HashMap<K, V>) -> Self {
		Value::Map(Box::new(m.into_iter().map(|(k, v)| (k.into(), v.into())).collect()))
	}
}

impl Value {
	pub fn map_from<K: Into<Key>, V: Into<Value>, I: IntoIterator<Item = (K, V)>>(
		iter: I,
	) -> Value {
		Value::Map(Box::new(iter.into_iter().map(|(k, v)| (k.into(), v.into())).collect()))
	}
}

macro_rules! try_into_impl {
	($enum:ident, $(($ty:ty, $var:ident)),+) => {
		$(impl TryInto<$ty> for $enum {
			type Error = ();
			fn try_into(self) -> Result<$ty, Self::Error> {
				match self {
					$enum::$var(v) => Ok(v as $ty),
					_ => Err(()),
				}
			}
		})+
	};
}
macro_rules! try_into_int_impl {
	($enum:ident, [$($ty:ty),+]) => {
		$(impl TryInto<$ty> for $enum {
			type Error = ();
			fn try_into(self) -> Result<$ty, Self::Error> {
				match self {
					$enum::Int(v) => Ok(v.try_into().map_err(|_| ())?),
					$enum::Uint(v) => Ok(v.try_into().map_err(|_| ())?),
					_ => Err(()),
				}
			}
		})+
	};
}
try_into_impl!(Value, (bool, Bool), (u64, Uint), (i64, Int), (f64, Float), (f32, Float));
try_into_impl!(Value, (String, Str), (DateTime<Utc>, Inst), (TimeDelta, Dur));
try_into_impl!(Value, ([u8; 16], UUID), (BigInt, BigInt));

try_into_int_impl!(Value, [u8, u16, u32, usize, i8, i16, i32, isize]);

try_into_impl!(Key, (bool, Bool), (u64, Uint), (i64, Int), (String, Str), (BigInt, BigInt));
try_into_impl!(Key, (DateTime<Utc>, Inst), (TimeDelta, Dur), ([u8; 16], UUID));
try_into_int_impl!(Key, [u8, u16, u32, usize, i8, i16, i32, isize]);

impl<T> TryInto<Vec<T>> for Value
where
	Value: TryInto<T>,
{
	type Error = ();
	fn try_into(self) -> Result<Vec<T>, Self::Error> {
		match self {
			Value::Arr(v) => {
				let mut vec = Vec::<T>::with_capacity(v.len());
				for item in v {
					vec.push(item.try_into().map_err(|_| ())?);
				}
				Ok(vec)
			}
			_ => Err(()),
		}
	}
}
impl<K, V> TryInto<HashMap<K, V>> for Value
where
	Key: TryInto<K>,
	Value: TryInto<V>,
	K: Eq + hash::Hash,
{
	type Error = ();
	fn try_into(self) -> Result<HashMap<K, V>, Self::Error> {
		match self {
			Value::Map(m) => {
				let mut map = HashMap::<K, V>::with_capacity(m.len());
				for (k, v) in *m {
					map.insert(k.try_into().map_err(|_| ())?, v.try_into().map_err(|_| ())?);
				}
				Ok(map)
			}
			_ => Err(()),
		}
	}
}

impl Value {
	/// cast value into `T`
	pub fn cast<T>(self) -> Option<T>
	where
		Value: TryInto<T>,
	{
		TryInto::try_into(self).ok()
	}
}
impl Key {
	/// cast key into `T`
	pub fn cast<T>(self) -> Option<T>
	where
		Key: TryInto<T>,
	{
		TryInto::try_into(self).ok()
	}
}

macro_rules! as_impl {
	($enum:ident, $(($ty:ty, $met:ident, $var:ident)),+) => {
		$(pub fn $met(&self) -> Option<$ty> {
			match self {
				$enum::$var(v) => Some(*v),
				_ => None,
			}
		})+
	};
}
macro_rules! as_ref_impl {
	($enum:ident, $(($ty:ty, $met:ident, $var:ident)),+) => {
		$(pub fn $met(&self) -> Option<&$ty> {
			match self {
				$enum::$var(v) => Some(v),
				_ => None,
			}
		})+
	};
}
macro_rules! as_mut_impl {
	($enum:ident, $(($ty:ty, $met:ident, $var:ident)),+) => {
		$(pub fn $met(&mut self) -> Option<&mut $ty> {
			match self {
				$enum::$var(v) => Some(v),
				_ => None,
			}
		})+
	};
}

/// `as_T() -> Option<T>`: get copy / reference of the inner value if it is of type `T`, else `None`.
///
/// `as_mut_T() -> Option<T>`: get mutable reference to the inner value if it is of type `T`, else `None`.
impl Value {
	as_impl!(Value, (bool, as_bool, Bool), (i64, as_int, Int), (u64, as_uint, Uint));
	as_impl!(Value, (f64, as_float, Float), ([u8; 16], as_uuid, UUID));
	as_impl!(Value, (TimeDelta, as_dur, Dur), (DateTime<Utc>, as_inst, Inst));
	as_ref_impl!(Value, (str, as_str, Str), ([Value], as_slice, Arr));
	as_ref_impl!(Value, (BigInt, as_bigint, BigInt), (HashMap<Key, Value>, as_map, Map));
	as_mut_impl!(Value, (Vec<Value>, as_vec_mut, Arr), (HashMap<Key, Value>, as_map_mut, Map));
}

/// `as_T() -> Option<T>`: get copy / reference of the inner value if it is of type `T`, else `None`.
impl Key {
	as_impl!(Key, (bool, as_bool, Bool), (i64, as_int, Int), ([u8; 16], as_uuid, UUID));
	as_impl!(Key, (TimeDelta, as_dur, Dur), (DateTime<Utc>, as_inst, Inst), (u64, as_uint, Uint));
	as_ref_impl!(Key, (str, as_str, Str), (BigInt, as_bigint, BigInt));
}

impl PartialEq<Value> for Value {
	fn eq(&self, other: &Value) -> bool {
		match (self, other) {
			(Value::Bool(a), Value::Bool(b)) => *a == *b,
			(Value::Int(a), Value::Int(b)) => *a == *b,
			(Value::Uint(a), Value::Uint(b)) => *a == *b,
			(Value::Int(a), Value::Uint(b)) => *a == *b as _,
			(Value::Uint(a), Value::Int(b)) => *a == *b as _,
			(Value::BigInt(a), Value::BigInt(b)) => a == b,
			(Value::Float(a), Value::Float(b)) => *a == *b,
			(Value::Str(a), Value::Str(b)) => a == b,
			(Value::Inst(a), Value::Inst(b)) => a == b,
			(Value::Dur(a), Value::Dur(b)) => a == b,
			(Value::UUID(a), Value::UUID(b)) => a == b,
			(Value::Arr(a), Value::Arr(b)) => a == b,
			(Value::Map(a), Value::Map(b)) => a == b,
			(Value::UnitVar(a), Value::UnitVar(b)) => a == b,
			_ => false,
		}
	}
}
impl PartialEq<Key> for Key {
	fn eq(&self, other: &Key) -> bool {
		match (self, other) {
			(Key::Bool(a), Key::Bool(b)) => *a == *b,
			(Key::Int(a), Key::Int(b)) => *a == *b,
			(Key::Uint(a), Key::Uint(b)) => *a == *b,
			(Key::Int(a), Key::Uint(b)) => *a == *b as _,
			(Key::Uint(a), Key::Int(b)) => *a == *b as _,
			(Key::BigInt(a), Key::BigInt(b)) => a == b,
			(Key::Str(a), Key::Str(b)) => a == b,
			(Key::Inst(a), Key::Inst(b)) => a == b,
			(Key::Dur(a), Key::Dur(b)) => a == b,
			(Key::UUID(a), Key::UUID(b)) => a == b,
			_ => false,
		}
	}
}

impl PartialEq<Key> for Value {
	fn eq(&self, other: &Key) -> bool {
		match (self, other) {
			(Value::Bool(a), Key::Bool(b)) => a == b,
			(Value::Int(a), Key::Int(b)) => a == b,
			(Value::Uint(a), Key::Uint(b)) => a == b,
			(Value::BigInt(a), Key::BigInt(b)) => a == b,
			(Value::Str(a), Key::Str(b)) => a == b,
			(Value::Inst(a), Key::Inst(b)) => a == b,
			(Value::Dur(a), Key::Dur(b)) => a == b,
			(Value::UUID(a), Key::UUID(b)) => a == b,
			_ => false,
		}
	}
}

macro_rules! eq_impl {
	($enum:ident, $(($ty:ty, $var:ident)),+) => {
		$(impl PartialEq<$ty> for $enum {
			fn eq(&self, other: &$ty) -> bool {
				match self {
					$enum::$var(v) => v == other,
					_ => false,
				}
			}
		})+
	};
}
macro_rules! eq_int_impl {
	($enum:ident, [$($ty:ty),+]) => {
		$(impl PartialEq<$ty> for $enum {
			fn eq(&self, other: &$ty) -> bool {
				match self {
					$enum::Uint(v) => *v as $ty == *other,
					$enum::Int(v) => *v as $ty == *other,
					_ => false,
				}
			}
		}
		impl PartialEq<$ty> for &$enum {
			fn eq(&self, other: &$ty) -> bool {
				match self {
					$enum::Uint(v) => *v as $ty == *other,
					$enum::Int(v) => *v as $ty == *other,
					_ => false,
				}
			}
		})+
	};
}

eq_impl!(Value, (bool, Bool), (DateTime<Utc>, Inst), (TimeDelta, Dur), (f64, Float));
eq_impl!(Value, (&str, Str), (String, Str), ([u8; 16], UUID), (BigInt, BigInt));

eq_int_impl!(Value, [u8, u16, u32, u64, usize]);
eq_int_impl!(Value, [i8, i16, i32, i64, isize]);

eq_impl!(Key, (bool, Bool), (DateTime<Utc>, Inst), (TimeDelta, Dur), (String, Str), (&str, Str));
eq_impl!(Key, (BigInt, BigInt), ([u8; 16], UUID));

eq_int_impl!(Key, [u8, u16, u32, u64, usize]);
eq_int_impl!(Key, [i8, i16, i32, i64, isize]);

impl<T> PartialEq<Vec<T>> for Value
where
	Value: PartialEq<T>,
{
	fn eq(&self, other: &Vec<T>) -> bool {
		match self {
			Value::Arr(a) => a == other,
			_ => false,
		}
	}
}

impl<I: SliceIndex<[Value]>> Index<I> for Value {
	type Output = <I as SliceIndex<[Value]>>::Output;
	fn index(&self, index: I) -> &Self::Output {
		match self {
			Value::Arr(a) => &a[index],
			_ => panic!(),
		}
	}
}
impl<I: SliceIndex<[Value]>> IndexMut<I> for Value {
	fn index_mut(&mut self, index: I) -> &mut Self::Output {
		match self {
			Value::Arr(a) => &mut a[index],
			_ => panic!(),
		}
	}
}
impl Index<&Key> for Value {
	type Output = Value;
	fn index(&self, index: &Key) -> &Self::Output {
		match self {
			Value::Map(m) => m.get(index).unwrap(),
			_ => panic!(),
		}
	}
}
impl IndexMut<&Key> for Value {
	fn index_mut(&mut self, index: &Key) -> &mut Self::Output {
		match self {
			Value::Map(m) => match m.contains_key(index) {
				true => m.get_mut(index).unwrap(),
				false => m.entry(index.clone()).or_insert(Value::default()),
			},
			_ => panic!(),
		}
	}
}
impl Value {
	/// get an item by index if value is an array, else return `None`.
	pub fn index_arr<I: SliceIndex<[Value]>>(
		&self, index: I,
	) -> Option<&<I as SliceIndex<[Value]>>::Output> {
		match self {
			Value::Arr(a) => a.get(index),
			_ => None,
		}
	}
	/// get a mutable reference to an item by index if value is an array, else return `None`.
	pub fn index_arr_mut<I: SliceIndex<[Value]>>(
		&mut self, index: I,
	) -> Option<&mut <I as SliceIndex<[Value]>>::Output> {
		match self {
			Value::Arr(a) => a.get_mut(index),
			_ => None,
		}
	}
	/// get an item by key if value is a map, else return `None`.
	pub fn index_map(&self, key: &Key) -> Option<&Value> {
		match self {
			Value::Map(m) => m.get(key),
			_ => None,
		}
	}
	/// get a mutable reference to an item by key if value is a map, else return `None`.
	pub fn index_map_mut(&mut self, key: &Key) -> Option<&mut Value> {
		match self {
			Value::Map(m) => m.get_mut(key),
			_ => None,
		}
	}
}

impl Display for Value {
	fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
		if f.alternate() {
			stringify(self, &StringifyOptions { ident: "\t", ..Default::default() }).fmt(f)
		} else {
			stringify(self, &StringifyOptions::default()).fmt(f)
		}
	}
}

impl Display for Key {
	fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
		str_key(self).fmt(f)
	}
}