//
//  ROMCatalogue.hpp
//  Clock Signal
//
//  Created by Thomas Harte on 01/06/2021.
//  Copyright © 2021 Thomas Harte. All rights reserved.
//

#pragma once

#include <algorithm>
#include <cstdint>
#include <functional>
#include <map>
#include <optional>
#include <set>
#include <string>
#include <vector>

namespace ROM {

enum Name {
	None,

	// Acorn Electron.
	AcornBASICII,
	AcornElectronMOS100,
	PRESADFSSlot1,
	PRESADFSSlot2,
	AcornADFS,
	PRESAdvancedPlus6,
	Acorn1770DFS,

	// Acorn Archimedes.
	AcornArthur030,
	AcornRISCOS200,
	AcornRISCOS311,
	AcornRISCOS319,

	// Amiga.
	AmigaKickstart10,
	AmigaKickstart11,
	AmigaKickstart12,
	AmigaA500Kickstart13,
	AmigaA3000Kickstart13,
	AmigaKickstart20,
	AmigaA500PlusKickstart204,
	AmigaA600Kickstart205,
	AmigaA500Kickstart31,

	AmigaDiagROM121,

	// Amstrad CPC.
	AMSDOS,
	CPC464Firmware,		CPC464BASIC,
	CPC664Firmware,		CPC664BASIC,
	CPC6128Firmware,	CPC6128BASIC,

	// Apple II.
	AppleIIOriginal,
	AppleIIPlus,
	AppleIICharacter,
	AppleIIe,
	AppleIIeCharacter,
	AppleIIEnhancedE,
	AppleIIEnhancedECharacter,
	AppleIISCSICard,

	// Apple IIgs.
	AppleIIgsROM00,
	AppleIIgsROM01,
	AppleIIgsROM03,
	AppleIIgsMicrocontrollerROM03,
	AppleIIgsCharacter,

	// Atari ST.
	AtariSTTOS100,
	AtariSTTOS104,

	// ColecoVision.
	ColecoVisionBIOS,

	// Commodore 1540/1541.
	Commodore1540,
	Commodore1541,

	// Disk II.
	DiskIIStateMachine16Sector,
	DiskIIBoot16Sector,
	DiskIIStateMachine13Sector,
	DiskIIBoot13Sector,

	// Enterprise.
	EnterpriseEXOS10,
	EnterpriseEXOS20,
	EnterpriseEXOS21,
	EnterpriseEXOS23,

	EnterpriseBASIC10,
	EnterpriseBASIC10Part1,
	EnterpriseBASIC10Part2,
	EnterpriseBASIC11,
	EnterpriseBASIC11Suffixed,
	EnterpriseBASIC21,

	EnterpriseEPDOS,
	EnterpriseEXDOS,

	// Macintosh.
	Macintosh128k,
	Macintosh512k,
	MacintoshPlus,

	// Master System.
	MasterSystemJapaneseBIOS,
	MasterSystemWesternBIOS,

	// MSX.
	MSXGenericBIOS,
	MSXJapaneseBIOS,
	MSXAmericanBIOS,
	MSXEuropeanBIOS,
	MSXDOS,

	MSX2GenericBIOS,
	MSX2Extension,
	MSXMusic,

	// Oric.
	OricColourROM,
	OricBASIC10,
	OricBASIC11,
	OricPravetzBASIC,
	OricByteDrive500,
	OricJasmin,
	OricMicrodisc,
	Oric8DOSBoot,

	// PCCompatible.
	PCCompatibleGLaBIOS,
	PCCompatibleGLaTICK,
	PCCompatiblePhoenix80286BIOS,

	PCCompatibleMDAFont,
	PCCompatibleCGAFont,
	PCCompatibleEGABIOS,
	PCCompatibleVGABIOS,

	// Plus 4.
	Plus4KernelPALv3,
	Plus4KernelPALv4,
	Plus4KernelPALv5,
	Plus4BASIC,

	// Sinclair QL.
	SinclairQLJS,

	// Vic-20.
	Vic20BASIC,
	Vic20EnglishCharacters,
	Vic20EnglishPALKernel,
	Vic20EnglishNTSCKernel,
	Vic20DanishCharacters,
	Vic20DanishKernel,
	Vic20JapaneseCharacters,
	Vic20JapaneseKernel,
	Vic20SwedishCharacters,
	Vic20SwedishKernel,

	// ZX80/81.
	ZX80,
	ZX81,

	// ZX Spectrum.
	Spectrum48k,
	Spectrum128k,
	SpecrumPlus2,
	SpectrumPlus3,

};

using Map = std::map<ROM::Name, std::vector<uint8_t>>;

struct Description {
	/// The ROM's enum name.
	Name name = Name::None;
	/// The machine with which this ROM is associated, in a form that is safe for using as
	/// part of a file name.
	std::string machine_name;
	/// A descriptive name for this ROM, suitable for use in a bullet-point list, a bracket
	/// clause, etc, e.g. "the Electron MOS 1.0".
	std::string descriptive_name;
	/// All idiomatic file name for this ROM, e.g. "os10.rom".
	std::vector<std::string> file_names;
	/// The expected size of this ROM in bytes, e.g. 32768.
	size_t size = 0;
	/// CRC32s for all known acceptable copies of this ROM; intended to allow a host platform
	/// to test user-provided ROMs of unknown provenance. **Not** intended to be used
	/// to exclude ROMs where the user's intent is otherwise clear.
	std::set<uint32_t> crc32s;

	/// Constructs the @c Description that correlates to @c name.
	Description(Name name);

	/// Constructs the @c Description that correlates to @c crc32, if any.
	static std::optional<Description> from_crc(uint32_t crc32);

	enum DescriptionFlag {
		Size = 1 << 0,
		CRC = 1 << 1,
		Filename = 1 << 2,
	};

	/// Provides a single-line of text describing this ROM, including the usual base text
	/// plus all the fields provided as @c flags .
	std::string description(int flags) const;

private:
	template <typename FileNameT, typename CRC32T> Description(
		Name name, std::string machine_name, std::string descriptive_name, FileNameT file_names, size_t size, CRC32T crc32s = uint32_t(0)
	) : name{name}, machine_name{machine_name}, descriptive_name{descriptive_name}, file_names{file_names}, size{size}, crc32s{crc32s} {
		// Slightly lazy: deal with the case where the constructor wasn't provided with any
		// CRCs by spotting that the set has exactly one member, which has value 0. The alternative
		// would be to provide a partial specialisation that never put anything into the set.
		if(this->crc32s.size() == 1 && !*this->crc32s.begin()) {
			this->crc32s.clear();
		}
	}
};

/// @returns a vector of all possible instances of ROM::Description — i.e. descriptions of every ROM
/// currently known to the ROM catalogue.
std::vector<Description> all_descriptions();

struct Request {
	Request(Name name, bool optional = false);
	Request() = default;

	/// Forms the request that would be satisfied by @c this plus the right-hand side.
	Request operator &&(const Request &);

	/// Forms the request that would be satisfied by either @c this or the right-hand side.
	Request operator ||(const Request &);

	/// Inspects the ROMMap to ensure that it satisfies this @c Request.
	/// @c returns @c true if the request is satisfied; @c false otherwise.
	///
	/// All ROMs in the map will be resized to their idiomatic sizes.
	bool validate(Map &) const;

	/// Returns a flattened array of all @c ROM::Descriptions that relate to anything
	/// anywhere in this ROM request.
	std::vector<Description> all_descriptions() const;

	/// @returns @c true if this request is empty, i.e. would be satisfied with no ROMs; @c false otherwise.
	bool empty();

	/// @returns what remains of this ROM request given that everything in @c map has been found.
	Request subtract(const ROM::Map &map) const;

	enum class ListType {
		Any, All, Single
	};
	void visit(
		const std::function<void(ListType, size_t size)> &enter_list,
		const std::function<void(void)> &exit_list,
		const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
	) const;

	enum class LineItem {
		NewList, Description
	};
	void visit(
		const std::function<void(LineItem, ListType, int level, const ROM::Description *, bool is_optional, size_t remaining)> &add_item
	) const;

	/// @returns a full bullet-pointed list of the requirements of this request, including
	/// appropriate conjuntives. This text is intended to be glued to the end of an opening
	/// portion of a sentence, e.g. "Please supply" + request.description(0, L'*').
	std::wstring description(int description_flags, wchar_t bullet_point);

private:
	struct Node {
		enum class Type {
			Any, All, One
		};
		Type type = Type::One;
		Name name = Name::None;
		/// @c true if this ROM is optional for machine startup. Generally indicates something
		/// that would make emulation more accurate, but not sufficiently so to make it
		/// a necessity.
		bool is_optional = false;
		std::vector<Node> children;

		bool empty() const {
			return type == Type::One && name == Name::None;
		}

		void add_descriptions(std::vector<Description> &) const;
		bool validate(Map &) const;
		void visit(
			const std::function<void(ListType, size_t)> &enter_list,
			const std::function<void(void)> &exit_list,
			const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
		) const;
		bool subtract(const ROM::Map &map);
		void sort() {
			// Don't do a full sort, but move anything optional to the back.
			// This makes them print more nicely; it's a human-facing tweak only.
			ssize_t index = ssize_t(children.size() - 1);
			bool has_seen_non_optional = false;
			while(index >= 0) {
				has_seen_non_optional |= !children[size_t(index)].is_optional;
				if(children[size_t(index)].is_optional && has_seen_non_optional) {
					std::rotate(children.begin() + index, children.begin() + index + 1, children.end());
				}
				--index;
			}
		}
	};
	Node node;

	Request append(Node::Type type, const Request &rhs);
};

}