#pragma once
#include "platform.h"
#include <algorithm>

namespace ks
{
struct ChatSwitchHook
{
    bool pressed[256]{};
    static bool candidate(UINT key, UINT mods)
    {
        bool shift = key == VK_SHIFT || key == VK_LSHIFT || key == VK_RSHIFT;
        bool alt = key == VK_MENU || key == VK_LMENU || key == VK_RMENU;
        return (key == VK_SPACE && (mods == MOD_WIN || mods == (MOD_WIN | MOD_SHIFT))) ||
            (shift && mods == MOD_ALT) || (alt && mods == MOD_SHIFT);
    }
    // 1 forward, 2 backward, -1 consumed repeat/release, 0 ordinary input.
    int update(UINT key, bool down, UINT mods, bool enabled)
    {
        if (key >= 256) return 0;
        if (pressed[key]) { if (!down) pressed[key] = false; return -1; }
        if (!down || !enabled) return 0;
        if (!candidate(key, mods)) return 0;
        pressed[key] = true;
        return key == VK_SPACE && (mods & MOD_SHIFT) ? 2 : 1;
    }
};
inline std::wstring chatTitle(HWND window)
{
    wchar_t title[1024]{};
    if (!window) return {};
    int length = GetWindowTextW(window, title, std::size(title));
    if (!length || length >= (int)std::size(title) - 1) return {};
    return title;
}
inline std::wstring chatKey(std::wstring process, std::wstring title)
{
    process = lower(process);
    if (process.ends_with(L".exe")) process.resize(process.size() - 4);
    while (!title.empty() && (title.front() == 0x200e || title.front() == 0x200f)) title.erase(0, 1);
    if (process == L"telegram")
    {
        // Telegram's unread badge is not part of the contact name.
        auto badge = title.rfind(L" \u2013 (");
        if (badge != title.npos && title.back() == L')')
        {
            auto digits = title.substr(badge + 4, title.size() - badge - 5);
            if (!digits.empty() && digits.find_first_not_of(L"0123456789") == digits.npos)
                title.resize(badge);
        }
        if (title.empty() || title == L"Telegram" || title.starts_with(L"Telegram (")) return {};
    }
    else if (process == L"ms-teams")
    {
        // Only the observed chat title format; meetings/search are not chats.
        const std::wstring prefix = L"Chat | ", suffix = L" | Microsoft Teams";
        if (!title.starts_with(prefix) || !title.ends_with(suffix) ||
            title.size() <= prefix.size() + suffix.size()) return {};
        title = title.substr(prefix.size(), title.size() - prefix.size() - suffix.size());
        if (title.empty()) return {};
    }
    else return {};
    return process + L"\n" + title;
}
inline std::wstring windowChatKey(HWND window)
{
    return window ? chatKey(processName(window), chatTitle(window)) : L"";
}
inline std::vector<std::wstring> chatCycle(const Settings &settings, const std::wstring &key,
                                         const std::vector<Layout> &layouts)
{
    auto found = settings.chatCycles.find(key);
    if (key.empty() || found == settings.chatCycles.end()) return settings.cycle;
    std::vector<std::wstring> result;
    for (const auto &id : found->second)
        if (std::any_of(layouts.begin(), layouts.end(), [&](const Layout &l) { return l.id == id; }))
            result.push_back(id);
    return result.empty() ? settings.cycle : result;
}
inline HKL nextChatLayout(const std::vector<std::wstring> &cycle, const std::vector<Layout> &layouts,
                          HKL current, bool reverse)
{
    std::vector<HKL> handles;
    for (const auto &id : cycle)
        for (const auto &layout : layouts)
            if (layout.id == id) handles.push_back(layout.handle);
    if (handles.empty()) return nullptr;
    auto found = std::find(handles.begin(), handles.end(), current);
    if (found == handles.end()) return handles.front();
    auto next = (size_t(found - handles.begin()) + (reverse ? handles.size() - 1 : 1)) % handles.size();
    return handles[next];
}
}