tsproto-structs 0.2.0

use std::str::FromStr;

use heck::*;
use once_cell::sync::Lazy;
use serde::Deserialize;

use crate::book::{BookDeclarations, Property, Struct};
use crate::messages::{Field, Message, MessageDeclarations};
use crate::*;

pub const DATA_STR: &str =
	include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/declarations/BookToMessages.toml"));

pub static DATA: Lazy<BookToMessagesDeclarations<'static>> = Lazy::new(|| {
	let rules: TomlStruct = toml::from_str(DATA_STR).unwrap();
	let book = &book::DATA;
	let messages = &messages::DATA;

	let decls: Vec<_> = rules
		.rule
		.into_iter()
		.map(|r| {
			let msg = messages.get_message(&r.to);
			let msg_fields =
				msg.attributes.iter().map(|a| messages.get_field(a)).collect::<Vec<_>>();
			let book_struct = book
				.structs
				.iter()
				.find(|s| s.name == r.from)
				.unwrap_or_else(|| panic!("Cannot find struct {}", r.from));

			let find_prop =
				|name: &str, book_struct: &'static Struct| -> Option<&'static Property> {
					book_struct.properties.iter().find(|p| p.name == *name)
				};

			// Map RuleProperty to RuleKind
			let to_rule_kind = |p: RuleProperty| {
				p.assert_valid();

				if p.function.is_some() {
					if p.type_s.is_some() {
						RuleKind::ArgumentFunction {
							type_s: p.type_s.unwrap(),
							from: p.from.unwrap(),
							name: p.function.unwrap(),
							to: p
								.tolist
								.unwrap()
								.into_iter()
								.map(|p| find_field(&p, &msg_fields))
								.collect(),
						}
					} else {
						RuleKind::Function {
							from: p.from.as_ref().map(|p| {
								find_prop(p, book_struct).unwrap_or_else(|| {
									panic!("No such (nested) property {} found in struct", p)
								})
							}),
							name: p.function.unwrap(),
							to: p
								.tolist
								.unwrap()
								.into_iter()
								.map(|p| find_field(&p, &msg_fields))
								.collect(),
						}
					}
				} else if let Some(prop) = find_prop(p.from.as_ref().unwrap(), book_struct) {
					RuleKind::Map { from: prop, to: find_field(&p.to.unwrap(), &msg_fields) }
				} else {
					RuleKind::ArgumentMap {
						from: p.from.unwrap(),
						to: find_field(&p.to.unwrap(), &msg_fields),
					}
				}
			};

			let mut ev = Event {
				op: r.operation.parse().expect("Failed to parse operation"),
				ids: r.ids.into_iter().map(to_rule_kind).collect(),
				msg,
				book_struct,
				rules: r.properties.into_iter().map(to_rule_kind).collect(),
			};

			// Add ids, which are required fields in the message.
			// The filter checks that the message is not optional.
			for field in msg_fields.iter().filter(|f| msg.attributes.iter().any(|a| *a == f.map)) {
				if !ev.ids.iter().any(|i| match i {
					RuleKind::Map { to, .. } => to == field,
					RuleKind::ArgumentMap { to, .. } => to == field,
					RuleKind::Function { to, .. } | RuleKind::ArgumentFunction { to, .. } => {
						to.contains(field)
					}
				}) {
					// Try to find matching property
					if let Some(prop) = book
						.get_struct(&ev.book_struct.name)
						.properties
						.iter()
						.find(|p| !p.opt && p.name == field.pretty)
					{
						ev.ids.push(RuleKind::Map { from: prop, to: field })
					}
					// The property may be in the properties
				}
			}

			// Add properties
			for field in msg_fields.iter().filter(|f| !msg.attributes.iter().any(|a| *a == f.map)) {
				if !ev.ids.iter().chain(ev.rules.iter()).any(|i| match i {
					RuleKind::Map { to, .. } => to == field,
					RuleKind::ArgumentMap { to, .. } => to == field,
					RuleKind::Function { to, .. } | RuleKind::ArgumentFunction { to, .. } => {
						to.contains(field)
					}
				}) {
					// We ignore that properties are set as option. In all current cases, it
					// makes no sense to set them to `None`, so we handle them the same way as
					// non-optional properties.
					if let Some(prop) = book
						.get_struct(&ev.book_struct.name)
						.properties
						.iter()
						.find(|p| p.name == field.pretty)
					{
						if !ev.ids.iter().chain(ev.rules.iter()).any(|i| i.from_name() == prop.name)
						{
							ev.rules.push(RuleKind::Map { from: prop, to: field })
						}
					}
				}
			}

			ev
		})
		.collect();

	BookToMessagesDeclarations { book, messages, decls }
});

#[derive(Debug)]
pub struct BookToMessagesDeclarations<'a> {
	pub book: &'a BookDeclarations,
	pub messages: &'a MessageDeclarations,
	pub decls: Vec<Event<'a>>,
}

#[derive(Debug)]
pub struct Event<'a> {
	pub op: RuleOp,
	pub msg: &'a Message,
	pub book_struct: &'a Struct,
	pub ids: Vec<RuleKind<'a>>,
	pub rules: Vec<RuleKind<'a>>,
}

#[derive(Debug)]
pub enum RuleKind<'a> {
	Map { from: &'a Property, to: &'a Field },
	ArgumentMap { from: String, to: &'a Field },
	Function { from: Option<&'a Property>, name: String, to: Vec<&'a Field> },
	ArgumentFunction { from: String, type_s: String, name: String, to: Vec<&'a Field> },
}

#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum RuleOp {
	Add,
	Remove,
	Update,
}

#[derive(Deserialize, Debug)]
#[serde(deny_unknown_fields)]
struct TomlStruct {
	rule: Vec<Rule>,
}

#[derive(Clone, Deserialize, Debug)]
#[serde(deny_unknown_fields)]
pub struct Rule {
	from: String,
	to: String,
	operation: String,
	#[serde(default = "Vec::new")]
	ids: Vec<RuleProperty>,
	#[serde(default = "Vec::new")]
	properties: Vec<RuleProperty>,
}

#[derive(Clone, Deserialize, Debug)]
#[serde(deny_unknown_fields)]
pub struct RuleProperty {
	from: Option<String>,
	to: Option<String>,

	#[serde(rename = "type")]
	type_s: Option<String>,
	function: Option<String>,
	tolist: Option<Vec<String>>,
}

impl RuleProperty {
	fn assert_valid(&self) {
		if let Some(to) = &self.to {
			assert!(self.from.is_some(), "to-property '{}' is invalid. It needs a 'from'", to);
			assert!(
				self.function.is_none(),
				"to-property '{}' is invalid. It must not have a 'function'",
				to
			);
			assert!(
				self.tolist.is_none(),
				"to-property '{}' is invalid. It must not have a 'tolist'",
				to
			);
			assert!(
				self.type_s.is_none(),
				"to-property '{}' is invalid. It must not have a 'type'",
				to
			);
		} else if let Some(fun) = &self.function {
			assert!(
				self.tolist.is_some(),
				"function-property '{}' is invalid. It needs 'tolist'",
				fun
			);
			assert!(
				self.type_s.is_none() || self.from.is_some(),
				"function-property '{}' is invalid. If the type ({:?}) is set, from must be set \
				 too",
				fun,
				self.type_s
			);
		} else {
			panic!(
				"Property is invalid. It needs either a 'to' or 'tolist'+'function'.Info: \
				 tolist={:?} type={:?} from={:?}",
				self.tolist, self.type_s, self.from
			);
		}
	}
}

impl FromStr for RuleOp {
	type Err = fmt::Error;
	fn from_str(s: &str) -> Result<Self> {
		if s == "add" {
			Ok(RuleOp::Add)
		} else if s == "remove" {
			Ok(RuleOp::Remove)
		} else if s == "update" {
			Ok(RuleOp::Update)
		} else {
			eprintln!("Cannot parse operation, needs to be add, remove or update");
			Err(fmt::Error)
		}
	}
}

// the in rust callable name (in PascalCase) from the field
fn find_field<'a>(name: &str, msg_fields: &[&'a Field]) -> &'a Field {
	*msg_fields
		.iter()
		.find(|f| f.pretty == name)
		.unwrap_or_else(|| panic!("Cannot find field '{}'", name))
}

impl<'a> RuleKind<'a> {
	pub fn from_name(&'a self) -> &'a str {
		match self {
			RuleKind::Map { from, .. } => &from.name,
			RuleKind::ArgumentMap { from, .. } => &from,
			RuleKind::Function { from, name, .. } => {
				&from.unwrap_or_else(|| panic!("From not set for function {}", name)).name
			}
			RuleKind::ArgumentFunction { from, .. } => &from,
		}
	}

	pub fn from_name_singular(&'a self) -> &'a str {
		let name = self.from_name();
		if let Some(s) = name.strip_suffix('s') { s } else { name }
	}

	pub fn from(&self) -> &'a Property {
		match self {
			RuleKind::Map { from, .. } => from,
			RuleKind::Function { from, name, .. } => {
				from.unwrap_or_else(|| panic!("From not set for function {}", name))
			}
			RuleKind::ArgumentMap { .. } | RuleKind::ArgumentFunction { .. } => {
				panic!("From is not a property for argument functions")
			}
		}
	}

	pub fn is_function(&self) -> bool {
		matches!(self, RuleKind::Function { .. } | RuleKind::ArgumentFunction { .. })
	}

	pub fn get_type(&self) -> RustType {
		match self {
			RuleKind::Map { .. } | RuleKind::Function { .. } => self.from().get_type().unwrap(),
			RuleKind::ArgumentMap { to, .. } => to.get_type("").unwrap(),
			RuleKind::ArgumentFunction { type_s, .. } => type_s.parse().unwrap(),
		}
	}

	pub fn get_type_no_option(&self) -> RustType {
		match self {
			RuleKind::Map { .. } => {
				let mut rust_type = self.from().clone();
				rust_type.opt = false;
				rust_type.get_type().unwrap()
			}
			_ => self.get_type(),
		}
	}

	pub fn get_argument(&self) -> String {
		format!("{}: {}", self.from_name().to_snake_case(), self.get_type().to_ref(true))
	}

	pub fn get_argument_no_option(&self) -> String {
		format!("{}: {}", self.from_name().to_snake_case(), self.get_type_no_option().to_ref(true))
	}
}

impl<'a> Event<'a> {
	/// The name of the change, could be a keyword.
	pub fn get_small_name(&self) -> String {
		// Strip own struct name and 'Request'
		self.msg.name.replace(&self.book_struct.name, "").replace("Request", "")
	}

	/// The small name, not a keyword
	pub fn get_change_name(&self) -> String {
		let small_change_name = self.get_small_name();
		if small_change_name == "Move" { self.msg.name.clone() } else { small_change_name }
	}
}