//! `hir_def` crate contains everything between macro expansion and type
//! inference.
//!
//! It defines various items (structs, enums, traits) which comprises Rust code,
//! as well as an algorithm for resolving paths to such entities.
//!
//! Note that `hir_def` is a work in progress, so not all of the above is
//! actually true.

pub mod db;

pub mod attr;
pub mod path;
pub mod type_ref;
pub mod builtin_type;
pub mod diagnostics;
pub mod per_ns;

pub mod dyn_map;
pub mod keys;

pub mod adt;
pub mod data;
pub mod generics;
pub mod lang_item;
pub mod docs;

pub mod expr;
pub mod body;
pub mod resolver;

mod trace;
pub mod nameres;

pub mod src;
pub mod child_by_source;

#[cfg(test)]
mod test_db;
#[cfg(test)]
mod marks;

use std::hash::Hash;

use hir_expand::{ast_id_map::FileAstId, AstId, HirFileId, InFile, MacroDefId};
use ra_arena::{impl_arena_id, RawId};
use ra_db::{impl_intern_key, salsa, CrateId};
use ra_syntax::ast;

use crate::builtin_type::BuiltinType;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct LocalImportId(RawId);
impl_arena_id!(LocalImportId);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ModuleId {
    pub krate: CrateId,
    pub local_id: LocalModuleId,
}

/// An ID of a module, **local** to a specific crate
// FIXME: rename to `LocalModuleId`.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct LocalModuleId(RawId);
impl_arena_id!(LocalModuleId);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct FunctionId(salsa::InternId);
impl_intern_key!(FunctionId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct FunctionLoc {
    pub container: AssocContainerId,
    pub ast_id: AstId<ast::FnDef>,
}

impl Intern for FunctionLoc {
    type ID = FunctionId;
    fn intern(self, db: &impl db::DefDatabase) -> FunctionId {
        db.intern_function(self)
    }
}

impl Lookup for FunctionId {
    type Data = FunctionLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> FunctionLoc {
        db.lookup_intern_function(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StructId(salsa::InternId);
impl_intern_key!(StructId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct StructLoc {
    pub container: ContainerId,
    pub ast_id: AstId<ast::StructDef>,
}

impl Intern for StructLoc {
    type ID = StructId;
    fn intern(self, db: &impl db::DefDatabase) -> StructId {
        db.intern_struct(self)
    }
}

impl Lookup for StructId {
    type Data = StructLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> StructLoc {
        db.lookup_intern_struct(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct UnionId(salsa::InternId);
impl_intern_key!(UnionId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct UnionLoc {
    pub container: ContainerId,
    pub ast_id: AstId<ast::UnionDef>,
}

impl Intern for UnionLoc {
    type ID = UnionId;
    fn intern(self, db: &impl db::DefDatabase) -> UnionId {
        db.intern_union(self)
    }
}

impl Lookup for UnionId {
    type Data = UnionLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> UnionLoc {
        db.lookup_intern_union(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct EnumId(salsa::InternId);
impl_intern_key!(EnumId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct EnumLoc {
    pub container: ContainerId,
    pub ast_id: AstId<ast::EnumDef>,
}

impl Intern for EnumLoc {
    type ID = EnumId;
    fn intern(self, db: &impl db::DefDatabase) -> EnumId {
        db.intern_enum(self)
    }
}

impl Lookup for EnumId {
    type Data = EnumLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> EnumLoc {
        db.lookup_intern_enum(*self)
    }
}

// FIXME: rename to `VariantId`, only enums can ave variants
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct EnumVariantId {
    pub parent: EnumId,
    pub local_id: LocalEnumVariantId,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct LocalEnumVariantId(RawId);
impl_arena_id!(LocalEnumVariantId);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StructFieldId {
    pub parent: VariantId,
    pub local_id: LocalStructFieldId,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct LocalStructFieldId(RawId);
impl_arena_id!(LocalStructFieldId);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ConstId(salsa::InternId);
impl_intern_key!(ConstId);
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct ConstLoc {
    pub container: AssocContainerId,
    pub ast_id: AstId<ast::ConstDef>,
}

impl Intern for ConstLoc {
    type ID = ConstId;
    fn intern(self, db: &impl db::DefDatabase) -> ConstId {
        db.intern_const(self)
    }
}

impl Lookup for ConstId {
    type Data = ConstLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> ConstLoc {
        db.lookup_intern_const(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StaticId(salsa::InternId);
impl_intern_key!(StaticId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct StaticLoc {
    pub container: ContainerId,
    pub ast_id: AstId<ast::StaticDef>,
}

impl Intern for StaticLoc {
    type ID = StaticId;
    fn intern(self, db: &impl db::DefDatabase) -> StaticId {
        db.intern_static(self)
    }
}

impl Lookup for StaticId {
    type Data = StaticLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> StaticLoc {
        db.lookup_intern_static(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TraitId(salsa::InternId);
impl_intern_key!(TraitId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct TraitLoc {
    pub container: ContainerId,
    pub ast_id: AstId<ast::TraitDef>,
}

impl Intern for TraitLoc {
    type ID = TraitId;
    fn intern(self, db: &impl db::DefDatabase) -> TraitId {
        db.intern_trait(self)
    }
}

impl Lookup for TraitId {
    type Data = TraitLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> TraitLoc {
        db.lookup_intern_trait(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeAliasId(salsa::InternId);
impl_intern_key!(TypeAliasId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct TypeAliasLoc {
    pub container: AssocContainerId,
    pub ast_id: AstId<ast::TypeAliasDef>,
}

impl Intern for TypeAliasLoc {
    type ID = TypeAliasId;
    fn intern(self, db: &impl db::DefDatabase) -> TypeAliasId {
        db.intern_type_alias(self)
    }
}

impl Lookup for TypeAliasId {
    type Data = TypeAliasLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> TypeAliasLoc {
        db.lookup_intern_type_alias(*self)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ImplId(salsa::InternId);
impl_intern_key!(ImplId);

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct ImplLoc {
    pub container: ModuleId,
    pub ast_id: AstId<ast::ImplBlock>,
}

impl Intern for ImplLoc {
    type ID = ImplId;
    fn intern(self, db: &impl db::DefDatabase) -> ImplId {
        db.intern_impl(self)
    }
}

impl Lookup for ImplId {
    type Data = ImplLoc;
    fn lookup(&self, db: &impl db::DefDatabase) -> ImplLoc {
        db.lookup_intern_impl(*self)
    }
}

macro_rules! impl_froms {
    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
        $(
            impl From<$v> for $e {
                fn from(it: $v) -> $e {
                    $e::$v(it)
                }
            }
            $($(
                impl From<$sv> for $e {
                    fn from(it: $sv) -> $e {
                        $e::$v($v::$sv(it))
                    }
                }
            )*)?
        )*
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeParamId {
    pub parent: GenericDefId,
    pub local_id: LocalTypeParamId,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct LocalTypeParamId(RawId);
impl_arena_id!(LocalTypeParamId);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ContainerId {
    ModuleId(ModuleId),
    DefWithBodyId(DefWithBodyId),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum AssocContainerId {
    ContainerId(ContainerId),
    ImplId(ImplId),
    TraitId(TraitId),
}
impl_froms!(AssocContainerId: ContainerId);

/// A Data Type
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum AdtId {
    StructId(StructId),
    UnionId(UnionId),
    EnumId(EnumId),
}
impl_froms!(AdtId: StructId, UnionId, EnumId);

/// The defs which can be visible in the module.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ModuleDefId {
    ModuleId(ModuleId),
    FunctionId(FunctionId),
    AdtId(AdtId),
    // Can't be directly declared, but can be imported.
    EnumVariantId(EnumVariantId),
    ConstId(ConstId),
    StaticId(StaticId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    BuiltinType(BuiltinType),
}
impl_froms!(
    ModuleDefId: ModuleId,
    FunctionId,
    AdtId(StructId, EnumId, UnionId),
    EnumVariantId,
    ConstId,
    StaticId,
    TraitId,
    TypeAliasId,
    BuiltinType
);

/// The defs which have a body.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum DefWithBodyId {
    FunctionId(FunctionId),
    StaticId(StaticId),
    ConstId(ConstId),
}

impl_froms!(DefWithBodyId: FunctionId, ConstId, StaticId);

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum AssocItemId {
    FunctionId(FunctionId),
    ConstId(ConstId),
    TypeAliasId(TypeAliasId),
}
// FIXME: not every function, ... is actually an assoc item. maybe we should make
// sure that you can only turn actual assoc items into AssocItemIds. This would
// require not implementing From, and instead having some checked way of
// casting them, and somehow making the constructors private, which would be annoying.
impl_froms!(AssocItemId: FunctionId, ConstId, TypeAliasId);

#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
pub enum GenericDefId {
    FunctionId(FunctionId),
    AdtId(AdtId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    ImplId(ImplId),
    // enum variants cannot have generics themselves, but their parent enums
    // can, and this makes some code easier to write
    EnumVariantId(EnumVariantId),
    // consts can have type parameters from their parents (i.e. associated consts of traits)
    ConstId(ConstId),
}
impl_froms!(
    GenericDefId: FunctionId,
    AdtId(StructId, EnumId, UnionId),
    TraitId,
    TypeAliasId,
    ImplId,
    EnumVariantId,
    ConstId
);

impl From<AssocItemId> for GenericDefId {
    fn from(item: AssocItemId) -> Self {
        match item {
            AssocItemId::FunctionId(f) => f.into(),
            AssocItemId::ConstId(c) => c.into(),
            AssocItemId::TypeAliasId(t) => t.into(),
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum AttrDefId {
    ModuleId(ModuleId),
    StructFieldId(StructFieldId),
    AdtId(AdtId),
    FunctionId(FunctionId),
    EnumVariantId(EnumVariantId),
    StaticId(StaticId),
    ConstId(ConstId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    MacroDefId(MacroDefId),
    ImplId(ImplId),
}

impl_froms!(
    AttrDefId: ModuleId,
    StructFieldId,
    AdtId(StructId, EnumId, UnionId),
    EnumVariantId,
    StaticId,
    ConstId,
    FunctionId,
    TraitId,
    TypeAliasId,
    MacroDefId,
    ImplId
);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum VariantId {
    EnumVariantId(EnumVariantId),
    StructId(StructId),
    UnionId(UnionId),
}
impl_froms!(VariantId: EnumVariantId, StructId);

trait Intern {
    type ID;
    fn intern(self, db: &impl db::DefDatabase) -> Self::ID;
}

pub trait Lookup {
    type Data;
    fn lookup(&self, db: &impl db::DefDatabase) -> Self::Data;
}

pub trait HasModule {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId;
}

impl HasModule for ContainerId {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        match *self {
            ContainerId::ModuleId(it) => it,
            ContainerId::DefWithBodyId(it) => it.module(db),
        }
    }
}

impl HasModule for AssocContainerId {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        match *self {
            AssocContainerId::ContainerId(it) => it.module(db),
            AssocContainerId::ImplId(it) => it.lookup(db).container,
            AssocContainerId::TraitId(it) => it.lookup(db).container.module(db),
        }
    }
}

impl HasModule for FunctionLoc {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        self.container.module(db)
    }
}

impl HasModule for TypeAliasLoc {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        self.container.module(db)
    }
}

impl HasModule for ConstLoc {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        self.container.module(db)
    }
}

impl HasModule for AdtId {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        match self {
            AdtId::StructId(it) => it.lookup(db).container,
            AdtId::UnionId(it) => it.lookup(db).container,
            AdtId::EnumId(it) => it.lookup(db).container,
        }
        .module(db)
    }
}

impl HasModule for DefWithBodyId {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        match self {
            DefWithBodyId::FunctionId(it) => it.lookup(db).module(db),
            DefWithBodyId::StaticId(it) => it.lookup(db).module(db),
            DefWithBodyId::ConstId(it) => it.lookup(db).module(db),
        }
    }
}

impl HasModule for GenericDefId {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        match self {
            GenericDefId::FunctionId(it) => it.lookup(db).module(db),
            GenericDefId::AdtId(it) => it.module(db),
            GenericDefId::TraitId(it) => it.lookup(db).container.module(db),
            GenericDefId::TypeAliasId(it) => it.lookup(db).module(db),
            GenericDefId::ImplId(it) => it.lookup(db).container,
            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
            GenericDefId::ConstId(it) => it.lookup(db).module(db),
        }
    }
}

impl HasModule for StaticLoc {
    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
        self.container.module(db)
    }
}