//! Completion for diagnostic attributes.

use ide_db::SymbolKind;
use syntax::ast;

use crate::{CompletionItem, Completions, context::CompletionContext};

use super::AttrCompletion;

pub(super) fn complete_on_unimplemented(
    acc: &mut Completions,
    ctx: &CompletionContext<'_, '_>,
    existing_keys: &[ast::Expr],
) {
    for attr in ATTRIBUTE_ARGS {
        let already_annotated = existing_keys
            .iter()
            .filter_map(|expr| match expr {
                ast::Expr::PathExpr(path) => path.path()?.as_single_name_ref(),
                ast::Expr::BinExpr(bin)
                    if bin.op_kind() == Some(ast::BinaryOp::Assignment { op: None }) =>
                {
                    match bin.lhs()? {
                        ast::Expr::PathExpr(path) => path.path()?.as_single_name_ref(),
                        _ => None,
                    }
                }
                _ => None,
            })
            .any(|it| {
                let text = it.text();
                attr.key() == text && text != "note"
            });
        if already_annotated {
            continue;
        }

        let mut item = CompletionItem::new(
            SymbolKind::BuiltinAttr,
            ctx.source_range(),
            attr.label,
            ctx.edition,
        );
        if let Some(lookup) = attr.lookup {
            item.lookup_by(lookup);
        }
        if let Some((snippet, cap)) = attr.snippet.zip(ctx.config.snippet_cap) {
            item.insert_snippet(cap, snippet);
        }
        item.add_to(acc, ctx.db);
    }
}

const ATTRIBUTE_ARGS: &[AttrCompletion] = &[
    super::attr(r#"label = "…""#, Some("label"), Some(r#"label = "${0:label}""#)),
    super::attr(r#"message = "…""#, Some("message"), Some(r#"message = "${0:message}""#)),
    super::attr(r#"note = "…""#, Some("note"), Some(r#"note = "${0:note}""#)),
];