// Copyright (c) 2011, Thomas Goyne <plorkyeran@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
// Aegisub Project http://www.aegisub.org/

/// @file hotkey_data_view_model.cpp
/// @see hotkey_data_view_model.h
/// @ingroup hotkey configuration_ui
///

#include "hotkey_data_view_model.h"

#include <libaegisub/exception.h>
#include <libaegisub/hotkey.h>
#include <libaegisub/make_unique.h>

#include "command/command.h"
#include "compat.h"
#include "include/aegisub/hotkey.h"
#include "preferences.h"

#include <wx/dataview.h>

#include <algorithm>
#include <list>
#include <set>

using namespace agi::hotkey;

/// @class HotkeyModelItem
/// @brief A base class for things exposed by HotkeyDataViewModel
class HotkeyModelItem {
protected:
	~HotkeyModelItem() = default;
public:
	virtual unsigned int GetChildren(wxDataViewItemArray &children) const=0;
	virtual wxDataViewItem GetParent() const=0;
	virtual void GetValue(wxVariant &variant, unsigned int col) const=0;
	virtual bool IsContainer() const=0;
	virtual bool SetValue(wxVariant const& variant, unsigned int col)=0;
};

class HotkeyModelRoot;
class HotkeyModelCategory;

/// @class HotkeyModelCombo
/// @brief A single hotkey exposed in the data view
///
/// All actual mutation of hotkeys happens through this class
class HotkeyModelCombo final : public HotkeyModelItem {
	HotkeyModelCategory *parent; ///< The containing category
	Combo combo;                 ///< The actual hotkey
	wxString cmd_name;
	wxString cmd_str;
public:
	HotkeyModelCombo(HotkeyModelCategory *parent, Combo const& combo)
	: parent(parent)
	, combo(combo)
	, cmd_name(to_wx(combo.CmdName()))
	, cmd_str(to_wx(combo.Str()))
	{
	}

	bool IsVisible(wxString const& filter) const {
		return cmd_name.Lower().Contains(filter) || cmd_str.Contains(filter);
	}

	void Apply(Hotkey::HotkeyMap *hk_map) {
		if (combo.CmdName().size() || combo.Str().size())
			hk_map->insert(make_pair(combo.CmdName(), combo));
	}

	unsigned int GetChildren(wxDataViewItemArray &) const override { return 0; }
	wxDataViewItem GetParent() const override { return wxDataViewItem(parent); }
	bool IsContainer() const override { return false; }

	void GetValue(wxVariant &variant, unsigned int col) const override {
		if (col == 0)
			variant = to_wx(combo.Str());
		else if (col == 1) {
			wxIcon icon;
			try {
				auto icon_bmp = cmd::get(combo.CmdName())->Icon(16);
				if (icon_bmp.IsOk())
					icon.CopyFromBitmap(icon_bmp);
			}
			catch (agi::Exception const&) {
				// Just use no icon; error is reported in the description column
			}
			variant << wxDataViewIconText(to_wx(combo.CmdName()), icon);
		}
		else if (col == 2) {
			try {
				variant = cmd::get(combo.CmdName())->StrHelp();
			}
			catch (agi::Exception const& e) {
				variant = to_wx(e.GetMessage());
			}
		}
		else
			throw agi::InternalError("HotkeyDataViewModel asked for an invalid column number");
	}

	bool SetValue(wxVariant const& variant, unsigned int col) override {
		if (col == 0) {
			wxArrayString toks = wxSplit(variant.GetString(), '-');
			std::vector<std::string> keys;
			keys.reserve(toks.size());
			transform(toks.begin(), toks.end(), back_inserter(keys), (std::string(*)(wxString const&))&from_wx);
			combo = Combo(combo.Context(), combo.CmdName(), keys);
			cmd_str = to_wx(combo.Str());
			return true;
		}
		else if (col == 1) {
			wxDataViewIconText text;
			text << variant;
			combo = Combo(combo.Context(), from_wx(text.GetText()), combo.Get());
			cmd_name = text.GetText();
			return true;
		}
		return false;
	}
};

/// A hotkey context exposed in the data view
class HotkeyModelCategory final : public HotkeyModelItem {
	std::list<HotkeyModelCombo> children;
	wxDataViewModel *model;
	wxString name;
	wxDataViewItemArray visible_items;
public:
	HotkeyModelCategory(wxDataViewModel *model, wxString const& name)
	: model(model)
	, name(wxGetTranslation(name))
	{
	}

	wxDataViewItem AddChild(Combo const& combo) {
		children.emplace_back(this, combo);
		visible_items.push_back(wxDataViewItem(&children.back()));
		model->ItemAdded(wxDataViewItem(this), wxDataViewItem(&children.back()));
		return wxDataViewItem(&children.back());
	}

	void Delete(wxDataViewItem const& item) {
		for (auto it = children.begin(); it != children.end(); ++it) {
			if (&*it == item.GetID()) {
				model->ItemDeleted(wxDataViewItem(this), wxDataViewItem((void*)&*it));
				children.erase(it);
				return;
			}
		}
	}

	void Apply(Hotkey::HotkeyMap *hk_map) {
		for (auto& combo : children)
			combo.Apply(hk_map);
	}

	void SetFilter(wxString const& new_filter) {
		std::set<HotkeyModelCombo*> old_visible;
		for (auto item : visible_items)
			old_visible.insert(static_cast<HotkeyModelCombo*>(item.GetID()));

		visible_items.clear();

		wxDataViewItemArray added;
		wxDataViewItemArray removed;

		for (auto& combo : children) {
			bool was_visible = old_visible.count(&combo) > 0;
			bool is_visible = combo.IsVisible(new_filter);

			if (is_visible)
				visible_items.push_back(wxDataViewItem(&combo));
			if (was_visible && !is_visible)
				removed.push_back(wxDataViewItem(&combo));
			if (is_visible && !was_visible)
				added.push_back(wxDataViewItem(&combo));
		}

		if (!added.empty())
			model->ItemsAdded(wxDataViewItem(this), added);
		if (!removed.empty())
			model->ItemsDeleted(wxDataViewItem(this), removed);
	}

	wxDataViewItem GetParent() const override { return wxDataViewItem(nullptr); }
	bool IsContainer() const override { return true; }
	bool SetValue(wxVariant const&, unsigned int) override { return false; }
	void GetValue(wxVariant &variant, unsigned int col) const override {
		if (col == 1)
			variant << wxDataViewIconText(name);
		else
			variant = name;
	}

	unsigned int GetChildren(wxDataViewItemArray &out) const override {
		out = visible_items;
		return out.size();
	}
};

/// The root containing the hotkey contexts
class HotkeyModelRoot final : public HotkeyModelItem {
	std::list<HotkeyModelCategory> categories;
public:
	HotkeyModelRoot(wxDataViewModel *model) {
		Hotkey::HotkeyMap const& hk_map = hotkey::inst->GetHotkeyMap();
		std::map<std::string, HotkeyModelCategory*> cat_map;

		for (auto const& category : hk_map) {
			std::string cat_name = category.second.Context();
			HotkeyModelCategory *cat;
			auto cat_it = cat_map.find(cat_name);
			if (cat_it != cat_map.end())
				cat = cat_it->second;
			else {
				categories.emplace_back(model, to_wx(cat_name));
				cat = cat_map[cat_name] = &categories.back();
			}

			cat->AddChild(category.second);
		}
	}

	void Apply(Hotkey::HotkeyMap *hk_map) {
		for (auto& category : categories)
			category.Apply(hk_map);
	}

	void SetFilter(wxString const& filter) {
		for (auto& category : categories)
			category.SetFilter(filter);
	}

	wxDataViewItem GetParent() const override { return wxDataViewItem(nullptr); }
	bool IsContainer() const override { return true; }
	bool SetValue(wxVariant const&, unsigned int) override { return false; }
	void GetValue(wxVariant &, unsigned int) const override { }

	unsigned int GetChildren(wxDataViewItemArray &out) const override {
		out.reserve(categories.size());
		for (auto const& category : categories)
			out.push_back(wxDataViewItem((void*)&category));
		return out.size();
	}
};

HotkeyDataViewModel::HotkeyDataViewModel(Preferences *parent)
: root(agi::make_unique<HotkeyModelRoot>(this))
, parent(parent)
{
}

const HotkeyModelItem * HotkeyDataViewModel::get(wxDataViewItem const& item) const {
	if (item.IsOk())
		return static_cast<HotkeyModelItem*>(item.GetID());
	return root.get();
}

HotkeyModelItem * HotkeyDataViewModel::get(wxDataViewItem const& item) {
	if (item.IsOk())
		return static_cast<HotkeyModelItem*>(item.GetID());
	return root.get();
}

unsigned int HotkeyDataViewModel::GetChildren(wxDataViewItem const& item, wxDataViewItemArray &children) const {
	return get(item)->GetChildren(children);
}

wxDataViewItem HotkeyDataViewModel::GetParent(wxDataViewItem const& item) const {
	return get(item)->GetParent();
}

void HotkeyDataViewModel::GetValue(wxVariant &variant, wxDataViewItem const& item, unsigned int col) const {
	get(item)->GetValue(variant, col);
}

bool HotkeyDataViewModel::IsContainer(wxDataViewItem const& item) const {
	return get(item)->IsContainer();
}

bool HotkeyDataViewModel::SetValue(wxVariant const& variant, wxDataViewItem const& item, unsigned int col) {
	if (!has_pending_changes) {
		has_pending_changes = true;
		parent->AddPendingChange(std::bind(&HotkeyDataViewModel::Apply, this));
	}
	return get(item)->SetValue(variant, col);
}

wxDataViewItem HotkeyDataViewModel::New(wxDataViewItem item) {
	if (!item.IsOk()) return wxDataViewItem();

	if (!IsContainer(item))
		item = GetParent(item);

	HotkeyModelCategory *ctx = static_cast<HotkeyModelCategory*>(item.GetID());
	wxVariant name;
	ctx->GetValue(name, 0);
	return ctx->AddChild(Combo(from_wx(name.GetString()), "", std::vector<std::string>()));
}

void HotkeyDataViewModel::Delete(wxDataViewItem const& item) {
	if (!item.IsOk() || IsContainer(item)) return;

	static_cast<HotkeyModelCategory*>(GetParent(item).GetID())->Delete(item);

	if (!has_pending_changes) {
		has_pending_changes = true;
		parent->AddPendingChange(std::bind(&HotkeyDataViewModel::Apply, this));
	}
}

void HotkeyDataViewModel::Apply() {
	Hotkey::HotkeyMap hk_map;
	root->Apply(&hk_map);
	hotkey::inst->SetHotkeyMap(hk_map);
	has_pending_changes = false;
}

void HotkeyDataViewModel::SetFilter(wxString const& filter) {
	root->SetFilter(filter.Lower());
}