use rustc_errors::{fluent, ErrorGuaranteed, Handler, IntoDiagnostic};
use rustc_macros::Diagnostic;
use rustc_middle::ty::{self, PolyTraitRef, Ty};
use rustc_span::{Span, Symbol};

#[derive(Diagnostic)]
#[diag(trait_selection_dump_vtable_entries)]
pub struct DumpVTableEntries<'a> {
    #[primary_span]
    pub span: Span,
    pub trait_ref: PolyTraitRef<'a>,
    pub entries: String,
}

#[derive(Diagnostic)]
#[diag(trait_selection_unable_to_construct_constant_value)]
pub struct UnableToConstructConstantValue<'a> {
    #[primary_span]
    pub span: Span,
    pub unevaluated: ty::UnevaluatedConst<'a>,
}

#[derive(Diagnostic)]
#[diag(trait_selection_empty_on_clause_in_rustc_on_unimplemented, code = "E0232")]
pub struct EmptyOnClauseInOnUnimplemented {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(trait_selection_invalid_on_clause_in_rustc_on_unimplemented, code = "E0232")]
pub struct InvalidOnClauseInOnUnimplemented {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(trait_selection_no_value_in_rustc_on_unimplemented, code = "E0232")]
#[note]
pub struct NoValueInOnUnimplemented {
    #[primary_span]
    #[label]
    pub span: Span,
}

pub struct NegativePositiveConflict<'tcx> {
    pub impl_span: Span,
    pub trait_desc: ty::TraitRef<'tcx>,
    pub self_ty: Option<Ty<'tcx>>,
    pub negative_impl_span: Result<Span, Symbol>,
    pub positive_impl_span: Result<Span, Symbol>,
}

impl IntoDiagnostic<'_> for NegativePositiveConflict<'_> {
    #[track_caller]
    fn into_diagnostic(
        self,
        handler: &Handler,
    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
        let mut diag = handler.struct_err(fluent::trait_selection_negative_positive_conflict);
        diag.set_arg("trait_desc", self.trait_desc.print_only_trait_path().to_string());
        diag.set_arg(
            "self_desc",
            self.self_ty.map_or_else(|| "none".to_string(), |ty| ty.to_string()),
        );
        diag.set_span(self.impl_span);
        diag.code(rustc_errors::error_code!(E0751));
        match self.negative_impl_span {
            Ok(span) => {
                diag.span_label(span, fluent::negative_implementation_here);
            }
            Err(cname) => {
                diag.note(fluent::negative_implementation_in_crate);
                diag.set_arg("negative_impl_cname", cname.to_string());
            }
        }
        match self.positive_impl_span {
            Ok(span) => {
                diag.span_label(span, fluent::positive_implementation_here);
            }
            Err(cname) => {
                diag.note(fluent::positive_implementation_in_crate);
                diag.set_arg("positive_impl_cname", cname.to_string());
            }
        }
        diag
    }
}