#include "Platform/Win32/EditorWindowScreenshotController.h"

#include "Support/ExecutablePath.h"

#include <chrono>
#include <cstdio>
#include <sstream>
#include <system_error>

namespace XCEngine::UI::Editor::App {

namespace {

std::filesystem::path ResolveBuildCaptureRoot(const std::filesystem::path& requestedCaptureRoot) {
    std::filesystem::path captureRoot = App::GetExecutableDirectory() / "captures";
    const std::filesystem::path scenarioPath = requestedCaptureRoot.parent_path().filename();
    if (!scenarioPath.empty() && scenarioPath != "captures") {
        captureRoot /= scenarioPath;
    }

    return captureRoot.lexically_normal();
}

} // namespace

void EditorWindowScreenshotController::Initialize(const std::filesystem::path& captureRoot) {
    m_captureRoot = ResolveBuildCaptureRoot(captureRoot);
    m_historyRoot = (m_captureRoot / "history").lexically_normal();
    m_latestCapturePath = (m_captureRoot / "latest.png").lexically_normal();
    m_activeHistoryCapturePath.clear();
    m_captureCount = 0;
    m_capturePending = false;
    m_pendingReason.clear();
    m_lastCaptureSummary = "Output: " + m_captureRoot.string();
    m_lastCaptureError.clear();
}

void EditorWindowScreenshotController::Shutdown() {
    m_activeHistoryCapturePath.clear();
    m_capturePending = false;
    m_pendingReason.clear();
}

void EditorWindowScreenshotController::RequestCapture(std::string reason) {
    m_pendingReason = reason.empty() ? "capture" : std::move(reason);
    m_capturePending = true;
}

bool EditorWindowScreenshotController::TryBeginCapture(std::filesystem::path& outHistoryPath) {
    outHistoryPath.clear();
    if (!m_capturePending) {
        return false;
    }

    std::error_code errorCode = {};
    std::filesystem::create_directories(m_captureRoot, errorCode);
    if (errorCode) {
        m_lastCaptureError = "Failed to create screenshot directory: " + m_captureRoot.string();
        m_lastCaptureSummary = "AutoShot failed";
        ResetPendingRequest();
        return false;
    }

    std::filesystem::create_directories(m_historyRoot, errorCode);
    if (errorCode) {
        m_lastCaptureError = "Failed to create screenshot directory: " + m_historyRoot.string();
        m_lastCaptureSummary = "AutoShot failed";
        ResetPendingRequest();
        return false;
    }

    m_activeHistoryCapturePath = BuildHistoryCapturePath(m_pendingReason);
    outHistoryPath = m_activeHistoryCapturePath;
    return true;
}

void EditorWindowScreenshotController::CompleteCaptureSuccess(
    const std::filesystem::path& historyPath) {
    const std::filesystem::path resolvedHistoryPath =
        historyPath.empty() ? m_activeHistoryCapturePath : historyPath;
    if (resolvedHistoryPath.empty()) {
        CompleteCaptureFailure("Capture completed without a valid history path.");
        return;
    }

    std::error_code errorCode = {};
    const std::uintmax_t historyFileSize =
        std::filesystem::file_size(resolvedHistoryPath, errorCode);
    if (errorCode || historyFileSize == 0u) {
        CompleteCaptureFailure("Capture completed without a valid PNG payload.");
        return;
    }

    errorCode.clear();
    std::filesystem::copy_file(
        resolvedHistoryPath,
        m_latestCapturePath,
        std::filesystem::copy_options::overwrite_existing,
        errorCode);
    if (errorCode) {
        m_lastCaptureError = "Failed to update latest screenshot: " + m_latestCapturePath.string();
        m_lastCaptureSummary = "AutoShot failed";
        ResetPendingRequest();
        return;
    }

    ++m_captureCount;
    m_lastCaptureError.clear();
    m_lastCaptureSummary =
        "Shot: latest.png | " + resolvedHistoryPath.filename().string();
    ResetPendingRequest();
}

void EditorWindowScreenshotController::CompleteCaptureFailure(std::string error) {
    if (!m_activeHistoryCapturePath.empty()) {
        std::error_code deleteError = {};
        std::filesystem::remove(m_activeHistoryCapturePath, deleteError);
    }

    m_lastCaptureError = error.empty()
        ? "Screenshot capture failed."
        : std::move(error);
    m_lastCaptureSummary = "AutoShot failed";
    ResetPendingRequest();
}

bool EditorWindowScreenshotController::HasPendingCapture() const {
    return m_capturePending;
}

const std::filesystem::path& EditorWindowScreenshotController::GetLatestCapturePath() const {
    return m_latestCapturePath;
}

const std::string& EditorWindowScreenshotController::GetLastCaptureSummary() const {
    return m_lastCaptureSummary;
}

const std::string& EditorWindowScreenshotController::GetLastCaptureError() const {
    return m_lastCaptureError;
}

void EditorWindowScreenshotController::ResetPendingRequest() {
    m_capturePending = false;
    m_pendingReason.clear();
    m_activeHistoryCapturePath.clear();
}

std::filesystem::path EditorWindowScreenshotController::BuildHistoryCapturePath(
    std::string_view reason) const {
    std::ostringstream filename;
    filename << BuildTimestampString()
             << '_'
             << (m_captureCount + 1u)
             << '_'
             << SanitizeReason(reason)
             << ".png";
    return (m_historyRoot / filename.str()).lexically_normal();
}

std::string EditorWindowScreenshotController::BuildTimestampString() {
    const auto now = std::chrono::system_clock::now();
    const std::time_t currentTime = std::chrono::system_clock::to_time_t(now);
    std::tm localTime = {};
    localtime_s(&localTime, &currentTime);

    char buffer[32] = {};
    std::snprintf(
        buffer,
        sizeof(buffer),
        "%04d%02d%02d_%02d%02d%02d",
        localTime.tm_year + 1900,
        localTime.tm_mon + 1,
        localTime.tm_mday,
        localTime.tm_hour,
        localTime.tm_min,
        localTime.tm_sec);
    return buffer;
}

std::string EditorWindowScreenshotController::SanitizeReason(std::string_view reason) {
    std::string sanitized = {};
    sanitized.reserve(reason.size());

    bool lastWasSeparator = false;
    for (const unsigned char value : reason) {
        if (std::isalnum(value)) {
            sanitized.push_back(static_cast<char>(std::tolower(value)));
            lastWasSeparator = false;
            continue;
        }

        if (!lastWasSeparator) {
            sanitized.push_back('_');
            lastWasSeparator = true;
        }
    }

    while (!sanitized.empty() && sanitized.front() == '_') {
        sanitized.erase(sanitized.begin());
    }
    while (!sanitized.empty() && sanitized.back() == '_') {
        sanitized.pop_back();
    }

    return sanitized.empty() ? "capture" : sanitized;
}

} // namespace XCEngine::UI::Editor::App