#![feature(str_as_str)]
#![feature(box_patterns)]
extern crate proc_macro;

pub(crate) use std::collections::BTreeMap;
pub(crate) use std::cmp::Ordering;
pub(crate) use std::sync::Arc;
pub(crate) use proc_macro::TokenStream;
pub(crate) use proc_macro2::{
    TokenStream as TokenStream2, Ident, Span, Punct, Group, Delimiter, Spacing::*
};
pub(crate) use syn::{
    parse_macro_input, ImplItem, ImplItemFn, LitStr, Type, TypePath,
    ItemImpl, ReturnType, Signature, FnArg, Pat, PatType, PatIdent,
    parse::{Parse, ParseStream, Result},
};
pub(crate) use quote::{quote, TokenStreamExt, ToTokens};
pub(crate) use heck::{AsKebabCase, AsUpperCamelCase};

mod proc_view;
mod proc_expose;
mod proc_command;

#[cfg(test)] use syn::parse_quote as pq;

#[proc_macro_attribute]
pub fn expose (meta: TokenStream, item: TokenStream) -> TokenStream {
    use self::proc_expose::{ExposeDef, ExposeMeta, ExposeImpl};
    write(ExposeDef(
        parse_macro_input!(meta as ExposeMeta),
        parse_macro_input!(item as ExposeImpl),
    ))
}

#[proc_macro_attribute]
pub fn command (meta: TokenStream, item: TokenStream) -> TokenStream {
    use self::proc_command::{CommandDef, CommandMeta, CommandImpl};
    write(CommandDef(
        parse_macro_input!(meta as CommandMeta),
        parse_macro_input!(item as CommandImpl),
    ))
}

#[proc_macro_attribute]
pub fn view (meta: TokenStream, item: TokenStream) -> TokenStream {
    use self::proc_view::{ViewDef, ViewMeta, ViewImpl};
    write(ViewDef(
        parse_macro_input!(meta as ViewMeta),
        parse_macro_input!(item as ViewImpl),
    ))
}

pub(crate) fn write <T: ToTokens> (t: T) -> TokenStream {
    let mut out = TokenStream2::new();
    t.to_tokens(&mut out);
    out.into()
}

pub(crate) fn write_quote (quote: TokenStream2) -> TokenStream2 {
    let mut out = TokenStream2::new();
    for token in quote {
        out.append(token);
    }
    out
}

pub(crate) fn write_quote_to (out: &mut TokenStream2, quote: TokenStream2) {
    for token in quote {
        out.append(token);
    }
}

#[cfg(test)] #[test] fn test_proc_view () {
    let x: crate::proc_view::ViewMeta = pq! { SomeOutput };
    let output: Ident = pq! { SomeOutput };
    assert_eq!(x.output, output);

    // TODO
    let _x: crate::proc_view::ViewImpl = pq! {
        impl Foo {
            /// docstring1
            #[tengri::view(":view1")] #[bar] fn a_view () {}

            #[baz]
            /// docstring2
            #[baz] fn is_not_view () {}
        }
    };
    let _expected_target: Ident = pq! { Foo };
    //assert_eq!(x.target, expected_target);
    //assert_eq!(x.items.len(), 2);
    //assert_eq!(x.items[0].item, pq! {
        ///// docstring1
        //#[bar] fn a_view () {}
    //});
    //assert_eq!(x.items[1].item, pq! {
        //#[baz]
        ///// docstring2
        //#[baz] fn is_not_view () {}
    //});
    //assert_eq!(x.syms, vec![
        //ViewArm( { symbol: pq! { ":view1" }, name: pq! { a_view }, },
    //]);
    // FIXME
    //let parsed: ViewDefinition = pq! {
        //#[tengri_proc::view(SomeOutput)]
        //impl SomeView {
            //#[tengri::view(":view-1")]
            //fn view_1 (&self) -> impl Render<SomeOutput> + use<'_> {
                //"view-1"
            //}
        //}
    //};
    //let written = quote! { #parsed };
    //assert_eq!(format!("{written}"), format!("{}", quote! {
        //impl SomeView {
            //fn view_1 (&self) -> impl Render<SomeOutput> + use<'_> {
                //"view-1"
            //}
        //}
        ///// Generated by [tengri_proc].
        //impl ::tengri::output::Content<SomeOutput> for SomeView {
            //fn content (&self) -> impl Render<SomeOutput> {
                //self.size.of(::tengri::output::View(self, self.config.view))
            //}
        //}
        ///// Generated by [tengri_proc].
        //impl<'a> ::tengri::dsl::ViewContext<'a, SomeOutput> for SomeView {
            //fn get_content_sym (&'a self, value: &Value<'a>) -> Option<RenderBox<'a, SomeOutput>> {
                //match value {
                    //::tengri::dsl::Value::Sym(":view-1") => self.view_1().boxed(),
                    //_ => panic!("expected Sym(content), got: {value:?}")
                //}
            //}
        //}
    //}));
}

//#[cfg(test)] #[test] fn test_expose_definition () {
    // TODO
    //let parsed: ExposeImpl = pq! {
        ////#[tengri_proc::expose]
        //impl Something {
            //fn something () -> bool {}
        //}
    //};
    //// FIXME:
    ////assert_eq!(
        ////format!("{}", quote! { #parsed }),
        ////format!("{}", quote! {
            ////impl Something {
                ////fn something () {}
            ////}
            ////impl ::tengri::Context<bool> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<bool> {
                    ////Some(match dsl {
                        ////::tengri::Value::Sym(":true")  => true,
                        ////::tengri::Value::Sym(":false") => false,
                        ////::tengri::Value::Sym(":bool1") => true || false,
                        ////_ => return None
                    ////})
                ////}
            ////}
        ////})
    ////);

    //let parsed: ExposeImpl = pq! {
        ////#[tengri_proc::expose]
        //impl Something {
            //#[tengri::expose(bool)] {
                //":bool1" => true || false,
            //}
            //#[tengri::expose(u16)] {
                //":u161" => 0 + 1,
            //}
            //#[tengri::expose(usize)] {
                //":usize1" => 1 + 2,
            //}
            //#[tengri::expose(Arc<str>)] {
                //":arcstr1" => "foo".into(),
            //}
            //#[tengri::expose(Option<Arc<str>>)] {
                //":optarcstr1" => Some("bar".into()),
                //":optarcstr2" => Some("baz".into()),
            //}
            //fn something () {}
        //}
    //};
    //// FIXME:
    ////assert_eq!(
        ////format!("{}", quote! { #parsed }),
        ////format!("{}", quote! {
            ////impl Something {
                ////fn something () {}
            ////}
            ////impl ::tengri::Context<Arc<str>> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<Arc<str>> {
                    ////Some(match dsl {
                        ////::tengri::Value::Sym(":arcstr1") => "foo".into(),
                        ////_ => return None
                    ////})
                ////}
            ////}
            ////impl ::tengri::Context<Option<Arc<str>>> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<Option<Arc<str>>> {
                    ////Some(match dsl {
                        ////::tengri::Value::Sym(":optarcstr1") => Some("bar".into()),
                        ////::tengri::Value::Sym(":optarcstr2") => Some("baz".into()),
                        ////_ => return None
                    ////})
                ////}
            ////}
            ////impl ::tengri::Context<bool> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<bool> {
                    ////Some(match dsl {
                        ////::tengri::Value::Sym(":true")  => true,
                        ////::tengri::Value::Sym(":false") => false,
                        ////::tengri::Value::Sym(":bool1") => true || false,
                        ////_ => return None
                    ////})
                ////}
            ////}
            ////impl ::tengri::Context<u16> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<u16> {
                    ////Some(match dsl {
                        ////::tengri::Value::Num(n) => *n as u16,
                        ////::tengri::Value::Sym(":u161") => 0 + 1,
                        ////_ => return None
                    ////})
                ////}
            ////}
            ////impl ::tengri::Context<usize> for Something {
                ////fn get (&self, dsl: &::tengri::Value) -> Option<usize> {
                    ////Some(match dsl {
                        ////::tengri::Value::Num(n) => *n as usize,
                        ////::tengri::Value::Sym(":usize1") => 1 + 2,
                        ////_ => return None
                    ////})
                ////}
            ////}
        ////})
    ////)
//}