whetstone_DSL/editor/src/LSPCompletionMerger.h

#pragma once
#include <algorithm>
#include <map>
#include <string>
#include <vector>

namespace whetstone {

struct CompletionItem {
    std::string label;
    int         kind   = 1;    // 1=Text 2=Method 3=Function 6=Variable etc.
    std::string detail;
    std::string source;        // language server that produced this item
};

class LSPCompletionMerger {
public:
    // Add items from a named source. Replaces any previous items from that source.
    void addItems(const std::string& source,
                  const std::vector<CompletionItem>& items) {
        bySource_[source] = items;
    }

    // Return all items merged from all sources, deduplicated by label.
    // When two sources offer the same label, the first encountered wins (sorted source order).
    std::vector<CompletionItem> getItems() const {
        std::vector<CompletionItem> result;
        std::map<std::string, bool> seen;
        for (const auto& [src, items] : bySource_) {
            for (const auto& item : items) {
                if (!seen.count(item.label)) {
                    seen[item.label] = true;
                    result.push_back(item);
                }
            }
        }
        std::sort(result.begin(), result.end(),
                  [](const CompletionItem& a, const CompletionItem& b){
                      return a.label < b.label;
                  });
        return result;
    }

    // Remove all items from one source.
    void clearSource(const std::string& source) {
        bySource_.erase(source);
    }

    // Remove all items.
    void clearAll() {
        bySource_.clear();
    }

    // Count unique labels across all sources.
    int uniqueCount() const {
        return static_cast<int>(getItems().size());
    }

    int sourceCount() const {
        return static_cast<int>(bySource_.size());
    }

private:
    // source → items
    std::map<std::string, std::vector<CompletionItem>> bySource_;
};

} // namespace whetstone