#pragma once
#include "PolyglotStackTraceDecoder.h"
#include <string>
#include <vector>

namespace whetstone {

class LanguageSeamFrameDetector {
public:
    // Returns indices of all frames where isBoundary == true.
    std::vector<int> detectSeams(const std::vector<StackFrame>& frames) const {
        std::vector<int> seams;
        for (int i = 0; i < static_cast<int>(frames.size()); ++i)
            if (frames[i].isBoundary) seams.push_back(i);
        return seams;
    }

    // Index of first seam frame, -1 if none.
    int primarySeam(const std::vector<StackFrame>& frames) const {
        for (int i = 0; i < static_cast<int>(frames.size()); ++i)
            if (frames[i].isBoundary) return i;
        return -1;
    }

    int seamCount(const std::vector<StackFrame>& frames) const {
        return static_cast<int>(detectSeams(frames).size());
    }

    // Unique languages in order of first appearance.
    std::vector<std::string> frameLanguages(const std::vector<StackFrame>& frames) const {
        std::vector<std::string> result;
        for (const auto& f : frames) {
            bool found = false;
            for (const auto& l : result) if (l == f.language) { found = true; break; }
            if (!found) result.push_back(f.language);
        }
        return result;
    }

    // True if any adjacent pair transitions from fromLang to toLang.
    bool crossesBoundary(const std::vector<StackFrame>& frames,
                         const std::string& fromLang,
                         const std::string& toLang) const {
        for (std::size_t i = 0; i + 1 < frames.size(); ++i)
            if (frames[i].language == fromLang && frames[i+1].language == toLang)
                return true;
        return false;
    }
};

} // namespace whetstone