/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2017 Furrtek
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

/* TODO:
 * - Paging menu items
 */

#include <algorithm>
#include "ui_fileman.hpp"
#include "string_format.hpp"
#include "portapack.hpp"
#include "event_m0.hpp"

using namespace portapack;
namespace fs = std::filesystem;

namespace {
using namespace ui;

bool is_hidden_file(const fs::path& path) {
	return !path.empty() && path.native()[0] == u'.';
}

// Gets a truncated name from a path for display.
std::string truncate(const fs::path& path, size_t max_length) {
	auto name = path.string();
	return name.length() <= max_length ? name : name.substr(0, max_length);
}

// Gets a human readable file size string.
std::string get_pretty_size(uint32_t file_size) {
	static const std::string suffix[5] = { "B", "kB", "MB", "GB", "??" };
	size_t suffix_index = 0;
	
	while (file_size >= 1024) {
		file_size /= 1024;
		suffix_index++;
	}

	if (suffix_index > 4)
		suffix_index = 4;
	
	return to_string_dec_uint(file_size) + suffix[suffix_index];
}

// Case insensitive path equality on underlying "native" string.
bool iequal(
	const fs::path& lhs,
	const fs::path& rhs
) {
	const auto& lhs_str = lhs.native();
	const auto& rhs_str = rhs.native();

	// NB: Not correct for Unicode/locales.
	if (lhs_str.length() == rhs_str.length()) {
		for (size_t i = 0; i < lhs_str.length(); ++i)
			if (towupper(lhs_str[i]) != towupper(rhs_str[i]))
				return false;

		return true;
	}

	return false;
}

// Inserts the entry into the entry list sorted directories first then by file name.
void insert_sorted(std::vector<fileman_entry>& entries, fileman_entry&& entry) {
	auto it = std::lower_bound(std::begin(entries), std::end(entries), entry,
		[](const fileman_entry& lhs, const fileman_entry& rhs) {
			if (lhs.is_directory && !rhs.is_directory)
				return true;
			else if (!lhs.is_directory && rhs.is_directory)
				return false;
			else
				return lhs.path < rhs.path;
		});

	entries.insert(it, std::move(entry));
}

// Returns the partner file path or an empty path if no partner is found.
fs::path get_partner_file(fs::path path) {
	if (fs::is_directory(path))
		return { };

	const fs::path txt_path{ u".TXT" };
	const fs::path c16_path{ u".C16" };
	auto ext = path.extension();

	if (iequal(ext, txt_path))
		ext = c16_path;
	else if (iequal(ext, c16_path))
		ext = txt_path;
	else
		return { };

	path.replace_extension(ext);
	return fs::file_exists(path) && !fs::is_directory(path) ? path : fs::path{ };
}

// Modal prompt to update the partner file if it exists.
// Runs continuation on_partner_action to update the partner file.
// Returns true is a partner is found, otherwise false.
// Path must be the full path to the file.
bool partner_file_prompt(
	NavigationView& nav,
	const fs::path& path,
	std::string action_name,
	std::function<void(const fs::path&, bool)> on_partner_action
) {
	auto partner = get_partner_file(path);

	if (partner.empty())
		return false;

	nav.push_under_current<ModalMessageView>(
		"Partner File",
		partner.filename().string() + "\n" + action_name + " this file too?",
		YESNO,
		[&nav, partner, on_partner_action](bool choice) {
			if (on_partner_action)
				on_partner_action(partner, choice);
		}
	);

	return true;
}

fs::path get_unique_filename(const fs::path& path, const fs::path& file) {
	auto stem = file.stem();
	auto ext = file.extension();
	auto serial = 1;
	fs::path new_path = file;

	while (fs::file_exists(path / new_path)) {
		new_path = stem;
		new_path += fs::path{ u"_" };
		new_path += to_string_dec_int(serial++);
		new_path += ext;
	}

	return new_path;
}

}

namespace ui {

/* FileManBaseView ***********************************************************/

void FileManBaseView::load_directory_contents(const fs::path& dir_path) {
	current_path = dir_path;
	entry_list.clear();
	auto filtering = !extension_filter.empty();

	text_current.set(dir_path.empty() ? "(sd root)" : truncate(dir_path, 24));
	
	for (const auto& entry : fs::directory_iterator(dir_path, u"*")) {
		// Hide files starting with '.' (hidden / tmp).
		if (is_hidden_file(entry.path()))
			continue;

		if (fs::is_regular_file(entry.status())) {
			if (!filtering || iequal(entry.path().extension(), extension_filter))
				insert_sorted(entry_list, { entry.path(), (uint32_t)entry.size(), false });
		} else if (fs::is_directory(entry.status())) {
			insert_sorted(entry_list, { entry.path(), 0, true });
		}
	}

	// Add "parent" directory if not at the root.
	if (!dir_path.empty())
		entry_list.insert(entry_list.begin(), { parent_dir_path, 0, true });
}

fs::path FileManBaseView::get_selected_full_path() const {
	if (get_selected_entry().path == parent_dir_path)
		return current_path.parent_path();

	return current_path / get_selected_entry().path;
}

const fileman_entry& FileManBaseView::get_selected_entry() const {
	// TODO: return reference to an "empty" entry on OOB?
	return entry_list[menu_view.highlighted_index()];
}

FileManBaseView::FileManBaseView(
	NavigationView& nav,
	std::string filter
) : nav_{ nav },
	extension_filter{ filter }
{
	add_children({
		&labels,
		&text_current,
		&text_info,
		&button_exit
	});

	button_exit.on_select = [this, &nav](Button&) {
		nav.pop();
	};

	if (!sdcIsCardInserted(&SDCD1)) {
		empty_ = EmptyReason::NoSDC;
		text_current.set("NO SD CARD!");
		return;
	}
	
	load_directory_contents(current_path);

	if (!entry_list.size()) {
		empty_ = EmptyReason::NoFiles;
		text_current.set("EMPTY SD CARD!");
	} else {
		menu_view.on_left = [this]() {
			pop_dir();
		};
	}
}

void FileManBaseView::focus() {
	if (empty_ != EmptyReason::NotEmpty) {
		button_exit.focus();
	} else {
		menu_view.focus();
	}
}

void FileManBaseView::push_dir(const fs::path& path) {
	if (path == parent_dir_path) {
		pop_dir();
	} else {
		current_path /= path;
		saved_index_stack.push_back(menu_view.highlighted_index());
		menu_view.set_highlighted(0);
		reload_current();
	}
}

void FileManBaseView::pop_dir() {
	if (saved_index_stack.empty())
		return;

	current_path = current_path.parent_path();
	reload_current();
	menu_view.set_highlighted(saved_index_stack.back());
	saved_index_stack.pop_back();
}

void FileManBaseView::refresh_list() {
	if (on_refresh_widgets)
		on_refresh_widgets(false);

	auto prev_highlight = menu_view.highlighted_index();
	menu_view.clear();
	
	for (const auto& entry : entry_list) {
		auto entry_name = truncate(entry.path, 20);
	
		if (entry.is_directory) {
			menu_view.add_item({
				entry_name,
				ui::Color::yellow(),
				&bitmap_icon_dir,
				[this](KeyEvent key) {
					if (on_select_entry)
						on_select_entry(key);
				}
			});
	
		} else {
			const auto& assoc = get_assoc(entry.path.extension());
			auto size_str = get_pretty_size(entry.size);
			
			menu_view.add_item({
				entry_name + std::string(21 - entry_name.length(), ' ') + size_str,
				assoc.color,
				assoc.icon,
				[this](KeyEvent key) {
					if (on_select_entry)
						on_select_entry(key);
				}
			});
		}

		// HACK: Should page menu items instead of limiting the number. 
		if (menu_view.item_count() >= max_items_shown)
			break;
	}

	text_info.set(menu_view.item_count() >= max_items_shown ? "Too many files!" : "");
	menu_view.set_highlighted(prev_highlight);
}

void FileManBaseView::reload_current() {
	load_directory_contents(current_path);
	refresh_list();
}

const FileManBaseView::file_assoc_t& FileManBaseView::get_assoc(
	const fs::path& ext) const
{
	size_t index = 0;

	for (; index < file_types.size() - 1; ++index)
		if (iequal(ext, file_types[index].extension))
			return file_types[index];

	// Default to last entry in the list.
	return file_types[index];
}

/* FileLoadView **************************************************************/

FileLoadView::FileLoadView(
	NavigationView& nav,
	std::string filter
) : FileManBaseView(nav, filter)
{
	on_refresh_widgets = [this](bool v) {
		refresh_widgets(v);
	};
	
	add_children({
		&menu_view
	});
	
	// Resize menu view to fill screen
	menu_view.set_parent_rect({ 0, 3 * 8, 240, 29 * 8 });
	
	refresh_list();
	
	on_select_entry = [this](KeyEvent) {
		if (get_selected_entry().is_directory) {
			push_dir(get_selected_entry().path);
		} else {
			nav_.pop();
			if (on_changed)
				on_changed(get_selected_full_path());
		}
	};
}

void FileLoadView::refresh_widgets(const bool) {
	set_dirty();
}

/* FileSaveView **************************************************************/
/*
FileSaveView::FileSaveView(
	NavigationView& nav,
	const fs::path& path,
	const fs::path& file
) : nav_{ nav },
	path_{ path },
	file_{ file }
{
	add_children({
		&labels,
		&text_path,
		&button_edit_path,
		&text_name,
		&button_edit_name,
		&button_save,
		&button_cancel,
	});
	
	button_edit_path.on_select = [this](Button&) {
		buffer_ = path_.string();
		text_prompt(nav_, buffer_, max_filename_length,
			[this](std::string&) {
				path_ = buffer_;
				refresh_widgets();
			});
	};

	button_edit_name.on_select = [this](Button&) {
		buffer_ = file_.string();
		text_prompt(nav_, buffer_, max_filename_length,
			[this](std::string&) {
				file_ = buffer_;
				refresh_widgets();
			});
	};

	button_save.on_select = [this](Button&) {
		if (on_save)
			on_save(path_ / file_);
		else
			nav_.pop();
	};

	button_cancel.on_select = [this](Button&) {
		nav_.pop();
	};

	refresh_widgets();
}

void FileSaveView::refresh_widgets() {
	text_path.set(truncate(path_, 30));
	text_name.set(truncate(file_, 30));
	set_dirty();
}
*/
/* FileManagerView ***********************************************************/

void FileManagerView::on_rename() {
	auto& entry = get_selected_entry();
	name_buffer = entry.path.filename().string();
	uint32_t cursor_pos = (uint32_t)name_buffer.length();

	if (auto pos = name_buffer.find_last_of(".");
		pos != name_buffer.npos && !entry.is_directory)
		cursor_pos = pos;

	text_prompt(nav_, name_buffer, cursor_pos, max_filename_length,
		[this](std::string& renamed) {
			auto renamed_path = fs::path{ renamed };
			rename_file(get_selected_full_path(), current_path / renamed_path);

			auto has_partner = partner_file_prompt(nav_, get_selected_full_path(), "Rename",
				[this, renamed_path](const fs::path& partner, bool should_rename) mutable {
					if (should_rename) {
						auto new_name = renamed_path.replace_extension(partner.extension());
						rename_file(current_path / partner, current_path / new_name);
					}
					reload_current();
				}
			);

			if (!has_partner)
				reload_current();
		});
}

void FileManagerView::on_delete() {
	auto name = get_selected_entry().path.filename().string();
	nav_.push<ModalMessageView>("Delete", "Delete " + name + "\nAre you sure?", YESNO,
		[this](bool choice) {
			if (choice) {
				delete_file(get_selected_full_path());

				auto has_partner = partner_file_prompt(
					nav_, get_selected_full_path(), "Delete",
					[this](const fs::path& partner, bool should_delete) {
						if (should_delete)
							delete_file(current_path / partner);
						reload_current();
					}
				);

				if (!has_partner)
					reload_current();
			}
		}
	);
}

void FileManagerView::on_new_dir() {
	name_buffer = "";
	text_prompt(nav_, name_buffer, max_filename_length, [this](std::string& dir_name) {
		make_new_directory(current_path / dir_name);
		reload_current();
	});
}

void FileManagerView::on_new_file() {
	name_buffer = "";
	text_prompt(nav_, name_buffer, max_filename_length, [this](std::string& file_name) {
		make_new_file(current_path / file_name);
		reload_current();
	});
}

void FileManagerView::on_paste() {
	// TODO: handle partner file. Need to fix nav stack first.
	auto new_name = get_unique_filename(current_path, clipboard_path.filename());
	fs::filesystem_error result;

	if (clipboard_mode == ClipboardMode::Cut)
		result = rename_file(clipboard_path, current_path / new_name);

	else if (clipboard_mode == ClipboardMode::Copy)
		result = copy_file(clipboard_path, current_path / new_name);

	if (result.code() != FR_OK)
		nav_.display_modal("Paste Failed", result.what());
	
	clipboard_path = fs::path{ };
	clipboard_mode = ClipboardMode::None;
	menu_view.focus();
	reload_current();
}

bool FileManagerView::selected_is_valid() const {
	return !entry_list.empty() &&
		get_selected_entry().path != parent_dir_path;
}

void FileManagerView::refresh_widgets(const bool v) {
	button_rename.hidden(v);
	button_delete.hidden(v);
	button_cut.hidden(v);
	button_copy.hidden(v);
	button_paste.hidden(v);
	button_new_dir.hidden(v);
	button_new_file.hidden(v);

	set_dirty();
}

FileManagerView::FileManagerView(
	NavigationView& nav
) : FileManBaseView(nav, "")
{
	// Don't bother with the UI in the case of no SDC.
	if (empty_ == EmptyReason::NoSDC)
		return;

	on_refresh_widgets = [this](bool v) {
		refresh_widgets(v);
	};
	
	add_children({
		&menu_view,
		&labels,
		&text_date,
		&button_rename,
		&button_delete,
		&button_cut,
		&button_copy,
		&button_paste,
		&button_new_dir,
		&button_new_file
	});
	
	menu_view.on_highlight = [this]() {
	if (selected_is_valid())
		text_date.set(to_string_FAT_timestamp(file_created_date(get_selected_full_path())));
	else
	text_date.set("");
	};
	
	refresh_list();

	on_select_entry = [this](KeyEvent key) {
		if (key == KeyEvent::Select && get_selected_entry().is_directory) {
			push_dir(get_selected_entry().path);
		} else {
			button_rename.focus();
		}
	};
	
	button_rename.on_select = [this]() {
		if (selected_is_valid())
			on_rename();
	};

	button_delete.on_select = [this]() {
		if (selected_is_valid())
			on_delete();
	};

	button_cut.on_select = [this]() {
		if (selected_is_valid() && !get_selected_entry().is_directory) {
			clipboard_path = get_selected_full_path();
			clipboard_mode = ClipboardMode::Cut;
		} else
			nav_.display_modal("Cut", "Can't cut that.");
	};

	button_copy.on_select = [this]() {
		if (selected_is_valid() && !get_selected_entry().is_directory) {
			clipboard_path = get_selected_full_path();
			clipboard_mode = ClipboardMode::Copy;
		} else
			nav_.display_modal("Copy", "Can't copy that.");
	};

	button_paste.on_select = [this]() {
		if (clipboard_mode != ClipboardMode::None)
			on_paste();
		else
			nav_.display_modal("Paste", "Cut or copy a file first.");
	};

	button_new_dir.on_select = [this]() {
		on_new_dir();
	};

	button_new_file.on_select = [this]() {
		on_new_file();
	};
}

}