// Copyright 2017 The Wuffs Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package builtin lists Wuffs' built-in concepts such as status codes.
package builtin

import (
	t "github.com/google/wuffs/lang/token"
)

var FourCCs = [...][2]string{
	{"ICCP", "International Color Consortium Profile"},
	{"XMP ", "Extensible Metadata Platform"},
}

var Statuses = [...]string{
	// Warnings.
	`"@end of data"`,

	// Suspensions.
	`"$short read"`,
	`"$short write"`,

	// Errors.
	`"#bad argument (length too short)"`,
	`"#bad argument"`,
	`"#bad call sequence"`,
	`"#bad receiver"`,
	`"#bad restart"`,
	`"#bad sizeof receiver"`,
	`"#bad workbuf length"`,
	`"#bad wuffs version"`,
	`"#cannot return a suspension"`,
	`"#disabled by previous error"`,
	`"#initialize falsely claimed already zeroed"`,
	`"#initialize not called"`,
	`"#interleaved coroutine calls"`,
	`"#not enough data"`,
	`"#too much data"`,
}

// TODO: a collection of forbidden variable names like and, or, not, as, ref,
// deref, false, true, in, out, this, u8, u16, etc?

var Types = []string{
	// TODO: i8, i16, i32, i64.
	"u8",
	"u16",
	"u32",
	"u64",

	"empty_struct",
	"bool",
	"utility",

	"range_ii_u32",
	"range_ie_u32",
	"range_ii_u64",
	"range_ie_u64",
	"rect_ie_u32",
	"rect_ii_u32",

	"io_reader",
	"io_writer",
	"status",

	"frame_config",
	"image_config",
	"pixel_buffer",
	"pixel_config",
	"pixel_swizzler",

	"decode_frame_options",
}

var Funcs = []string{
	"u8.high_bits(n u32[..8]) u8",
	"u8.low_bits(n u32[..8]) u8",
	"u8.max(x u8) u8",
	"u8.min(x u8) u8",

	"u16.high_bits(n u32[..16]) u16",
	"u16.low_bits(n u32[..16]) u16",
	"u16.max(x u16) u16",
	"u16.min(x u16) u16",

	"u32.high_bits(n u32[..32]) u32",
	"u32.low_bits(n u32[..32]) u32",
	"u32.max(x u32) u32",
	"u32.min(x u32) u32",

	"u64.high_bits(n u32[..64]) u64",
	"u64.low_bits(n u32[..64]) u64",
	"u64.max(x u64) u64",
	"u64.min(x u64) u64",

	// ---- utility

	"utility.make_range_ii_u32(min_incl u32, max_incl u32) range_ii_u32",
	"utility.make_range_ie_u32(min_incl u32, max_excl u32) range_ie_u32",
	"utility.make_range_ii_u64(min_incl u64, max_incl u64) range_ii_u64",
	"utility.make_range_ie_u64(min_incl u64, max_excl u64) range_ie_u64",
	"utility.make_rect_ii_u32(min_incl_x u32, min_incl_y u32, max_incl_x u32, max_incl_y u32) rect_ii_u32",
	"utility.make_rect_ie_u32(min_incl_x u32, min_incl_y u32, max_excl_x u32, max_excl_y u32) rect_ie_u32",
	"utility.null_io_reader() io_reader",
	"utility.null_io_writer() io_writer",
	"utility.null_slice_u8() slice u8",

	// ---- ranges

	"range_ie_u32.reset!()",
	"range_ie_u32.get_min_incl() u32",
	"range_ie_u32.get_max_excl() u32",
	"range_ie_u32.intersect(r range_ie_u32) range_ie_u32",
	"range_ie_u32.unite(r range_ie_u32) range_ie_u32",

	"range_ii_u32.reset!()",
	"range_ii_u32.get_min_incl() u32",
	"range_ii_u32.get_max_incl() u32",
	"range_ii_u32.intersect(r range_ii_u32) range_ii_u32",
	"range_ii_u32.unite(r range_ii_u32) range_ii_u32",

	"range_ie_u64.reset!()",
	"range_ie_u64.get_min_incl() u64",
	"range_ie_u64.get_max_excl() u64",
	"range_ie_u64.intersect(r range_ie_u64) range_ie_u64",
	"range_ie_u64.unite(r range_ie_u64) range_ie_u64",

	"range_ii_u64.reset!()",
	"range_ii_u64.get_min_incl() u64",
	"range_ii_u64.get_max_incl() u64",
	"range_ii_u64.intersect(r range_ii_u64) range_ii_u64",
	"range_ii_u64.unite(r range_ii_u64) range_ii_u64",

	// ---- io_reader

	"io_reader.can_undo_byte() bool",
	"io_reader.undo_byte!()",

	"io_reader.read_u8?() u8",

	"io_reader.read_u16be?() u16",
	"io_reader.read_u16le?() u16",

	"io_reader.read_u8_as_u32?() u32[..0xFF]",
	"io_reader.read_u16be_as_u32?() u32[..0xFFFF]",
	"io_reader.read_u16le_as_u32?() u32[..0xFFFF]",
	"io_reader.read_u24be_as_u32?() u32[..0xFFFFFF]",
	"io_reader.read_u24le_as_u32?() u32[..0xFFFFFF]",
	"io_reader.read_u32be?() u32",
	"io_reader.read_u32le?() u32",

	"io_reader.read_u8_as_u64?() u64[..0xFF]",
	"io_reader.read_u16be_as_u64?() u64[..0xFFFF]",
	"io_reader.read_u16le_as_u64?() u64[..0xFFFF]",
	"io_reader.read_u24be_as_u64?() u64[..0xFFFFFF]",
	"io_reader.read_u24le_as_u64?() u64[..0xFFFFFF]",
	"io_reader.read_u32be_as_u64?() u64[..0xFFFFFFFF]",
	"io_reader.read_u32le_as_u64?() u64[..0xFFFFFFFF]",
	"io_reader.read_u40be_as_u64?() u64[..0xFFFFFFFFFF]",
	"io_reader.read_u40le_as_u64?() u64[..0xFFFFFFFFFF]",
	"io_reader.read_u48be_as_u64?() u64[..0xFFFFFFFFFFFF]",
	"io_reader.read_u48le_as_u64?() u64[..0xFFFFFFFFFFFF]",
	"io_reader.read_u56be_as_u64?() u64[..0xFFFFFFFFFFFFFF]",
	"io_reader.read_u56le_as_u64?() u64[..0xFFFFFFFFFFFFFF]",
	"io_reader.read_u64be?() u64",
	"io_reader.read_u64le?() u64",

	// TODO: these should have an explicit pre-condition "available() >= N".
	// For now, that's implicitly checked (i.e. hard coded).
	//
	// The io_reader has peek_etc methods and skip_fast, not read_etc_fast,
	// because we sometimes advance the pointer by less than what's read. See
	// https://fgiesen.wordpress.com/2018/02/20/reading-bits-in-far-too-many-ways-part-2/

	"io_reader.peek_u8() u8",

	"io_reader.peek_u16be() u16",
	"io_reader.peek_u16le() u16",

	"io_reader.peek_u8_as_u32() u32[..0xFF]",
	"io_reader.peek_u16be_as_u32() u32[..0xFFFF]",
	"io_reader.peek_u16le_as_u32() u32[..0xFFFF]",
	"io_reader.peek_u24be_as_u32() u32[..0xFFFFFF]",
	"io_reader.peek_u24le_as_u32() u32[..0xFFFFFF]",
	"io_reader.peek_u32be() u32",
	"io_reader.peek_u32le() u32",

	"io_reader.peek_u8_as_u64() u64[..0xFF]",
	"io_reader.peek_u16be_as_u64() u64[..0xFFFF]",
	"io_reader.peek_u16le_as_u64() u64[..0xFFFF]",
	"io_reader.peek_u24be_as_u64() u64[..0xFFFFFF]",
	"io_reader.peek_u24le_as_u64() u64[..0xFFFFFF]",
	"io_reader.peek_u32be_as_u64() u64[..0xFFFFFFFF]",
	"io_reader.peek_u32le_as_u64() u64[..0xFFFFFFFF]",
	"io_reader.peek_u40be_as_u64() u64[..0xFFFFFFFFFF]",
	"io_reader.peek_u40le_as_u64() u64[..0xFFFFFFFFFF]",
	"io_reader.peek_u48be_as_u64() u64[..0xFFFFFFFFFFFF]",
	"io_reader.peek_u48le_as_u64() u64[..0xFFFFFFFFFFFF]",
	"io_reader.peek_u56be_as_u64() u64[..0xFFFFFFFFFFFFFF]",
	"io_reader.peek_u56le_as_u64() u64[..0xFFFFFFFFFFFFFF]",
	"io_reader.peek_u64be() u64",
	"io_reader.peek_u64le() u64",

	"io_reader.available() u64",
	"io_reader.position() u64",
	"io_reader.set!(s slice u8, closed bool)", // TODO: remove, as it's no longer used?
	"io_reader.set_limit!(l u64)",             // TODO: remove, as it's no longer used?
	"io_reader.set_mark!()",
	"io_reader.since_mark() slice u8",
	"io_reader.take!(n u64) slice u8",

	"io_reader.skip?(n u32)",

	// TODO: this should have explicit pre-conditions "actual <= worst_case"
	// and "worst_case <= available()". As an implementation restriction, we
	// also require that worst_case has a constant value. For now, that's all
	// implicitly checked (i.e. hard coded).
	"io_reader.skip_fast!(actual u32, worst_case u32)",

	// ---- io_writer

	"io_writer.write_u8?(x u8)",
	"io_writer.write_u16be?(x u16)",
	"io_writer.write_u16le?(x u16)",
	"io_writer.write_u24be?(x u32[..0xFFFFFF])",
	"io_writer.write_u24le?(x u32[..0xFFFFFF])",
	"io_writer.write_u32be?(x u32)",
	"io_writer.write_u32le?(x u32)",
	"io_writer.write_u40be?(x u64[..0xFFFFFFFFFF])",
	"io_writer.write_u40le?(x u64[..0xFFFFFFFFFF])",
	"io_writer.write_u48be?(x u64[..0xFFFFFFFFFFFF])",
	"io_writer.write_u48le?(x u64[..0xFFFFFFFFFFFF])",
	"io_writer.write_u56be?(x u64[..0xFFFFFFFFFFFFFF])",
	"io_writer.write_u56le?(x u64[..0xFFFFFFFFFFFFFF])",
	"io_writer.write_u64be?(x u64)",
	"io_writer.write_u64le?(x u64)",

	// TODO: these should have an explicit pre-condition "available() >= N".
	// For now, that's implicitly checked (i.e. hard coded).
	//
	// The io_writer has write_fast_etc methods, not poke_etc and skip_fast,
	// because skip_fast could leave uninitialized bytes in the io_buffer.
	"io_writer.write_fast_u8!(x u8)",
	"io_writer.write_fast_u16be!(x u16)",
	"io_writer.write_fast_u16le!(x u16)",
	"io_writer.write_fast_u24be!(x u32[..0xFFFFFF])",
	"io_writer.write_fast_u24le!(x u32[..0xFFFFFF])",
	"io_writer.write_fast_u32be!(x u32)",
	"io_writer.write_fast_u32le!(x u32)",
	"io_writer.write_fast_u40be!(x u64[..0xFFFFFFFFFF])",
	"io_writer.write_fast_u40le!(x u64[..0xFFFFFFFFFF])",
	"io_writer.write_fast_u48be!(x u64[..0xFFFFFFFFFFFF])",
	"io_writer.write_fast_u48le!(x u64[..0xFFFFFFFFFFFF])",
	"io_writer.write_fast_u56be!(x u64[..0xFFFFFFFFFFFFFF])",
	"io_writer.write_fast_u56le!(x u64[..0xFFFFFFFFFFFFFF])",
	"io_writer.write_fast_u64be!(x u64)",
	"io_writer.write_fast_u64le!(x u64)",

	"io_writer.available() u64",
	"io_writer.position() u64",
	"io_writer.set!(s slice u8)",  // TODO: remove, as it's no longer used?
	"io_writer.set_limit!(l u64)", // TODO: remove, as it's no longer used?
	"io_writer.set_mark!()",
	"io_writer.since_mark() slice u8",

	"io_writer.copy_from_slice!(s slice u8) u64",
	"io_writer.copy_n_from_history!(n u32, distance u32) u32",
	"io_writer.copy_n_from_reader!(n u32, r io_reader) u32",
	"io_writer.copy_n_from_slice!(n u32, s slice u8) u32",

	// TODO: this should have explicit pre-conditions:
	//  - n <= this.available()
	//  - distance > 0
	//  - distance <= this.since_mark().length()
	// For now, that's all implicitly checked (i.e. hard coded).
	"io_writer.copy_n_from_history_fast!(n u32, distance u32) u32",

	// ---- status

	// TODO: should we add is_complete?
	"status.is_error() bool",
	"status.is_ok() bool",
	"status.is_suspension() bool",
	"status.is_warning() bool",

	// ---- frame_config
	// Duration's upper bound is the maximum possible i64 value.

	"frame_config.blend() u8",
	"frame_config.disposal() u8",
	"frame_config.duration() u64[..0x7FFFFFFFFFFFFFFF]",
	"frame_config.index() u64",
	"frame_config.io_position() u64",

	"frame_config.update!(bounds rect_ie_u32, duration u64[..0x7FFFFFFFFFFFFFFF], " +
		"index u64, io_position u64, blend u8, disposal u8)",

	// ---- image_config

	"image_config.set!(pixfmt u32, pixsub u32, width u32, height u32, " +
		"first_frame_io_position u64, first_frame_is_opaque bool)",

	// ---- pixel_buffer

	"pixel_buffer.palette() slice u8",
	"pixel_buffer.pixel_format() u32",
	"pixel_buffer.plane(p u32[..3]) table u8",

	// ---- pixel_swizzler

	"pixel_swizzler.prepare!(dst_pixfmt u32, dst_palette slice u8, src_pixfmt u32, src_palette slice u8)",
	"pixel_swizzler.swizzle_packed!(dst slice u8, dst_palette slice u8, src slice u8) u64",
}

// The "T1" and "T2" types here are placeholders for generic "slice T" or
// "table T" types. After tokenizing (but before parsing) these XxxFunc strings
// (e.g. in the lang/check package), replace "T1" and "T2" with "†" or "‡"
// daggers, to avoid collision with a user-defined "T1" or "T2" type.

const (
	GenericOldName1 = t.IDT1
	GenericOldName2 = t.IDT2
	GenericNewName1 = t.IDDagger1
	GenericNewName2 = t.IDDagger2
)

var SliceFuncs = []string{
	"T1.copy_from_slice!(s T1) u64",
	"T1.length() u64",
	"T1.prefix(up_to u64) T1",
	"T1.suffix(up_to u64) T1",
}

var TableFuncs = []string{
	"T2.height() u64",
	"T2.stride() u64",
	"T2.width() u64",

	"T2.row(y u32) T1",
}