// Package d2compression is used for decompressing WAV files.
package d2compression

// MpqHuffman.go based on the original CS file
//
// Authors:
//		Foole (fooleau@gmail.com)
//      Tim Sarbin (tim.sarbin@gmail.com) (go translation)
//
// (C) 2006 Foole (fooleau@gmail.com)
// Based on code from StormLib by Ladislav Zezula and ShadowFlare
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

import (
	"log"

	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2datautils"
)

// linkedNode is a node which is both hierachcical (parent/child) and doubly linked (next/prev)
type linkedNode struct {
	decompressedValue int
	weight            int
	parent            *linkedNode
	child0            *linkedNode
	prev              *linkedNode
	next              *linkedNode
}

// createLinkedNode creates a linked node
func createLinkedNode(decompVal, weight int) *linkedNode {
	result := &linkedNode{
		decompressedValue: decompVal,
		weight:            weight,
	}

	return result
}

func (v *linkedNode) getChild1() *linkedNode {
	return v.child0.prev
}

func (v *linkedNode) insert(other *linkedNode) *linkedNode {
	// 'next' should have a lower weight we should return the lower weight
	if other.weight <= v.weight {
		// insert before
		if v.next != nil {
			v.next.prev = other
			other.next = v.next
		}

		v.next = other

		other.prev = v

		return other
	}

	if v.prev == nil {
		// insert after
		other.prev = nil
		v.prev = other
		other.next = v
	} else {
		v.prev.insert(other)
	}

	return v
}

//nolint:funlen // Makes no sense to split
func getPrimes() [][]byte {
	return [][]byte{
		{ //nolint:dupl we're not interested in duplicates here
			// Compression type 0
			0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
		},
		{ //nolint:dupl we're not interested in duplicates here
			// Compression type 1
			0x54, 0x16, 0x16, 0x0D, 0x0C, 0x08, 0x06, 0x05, 0x06, 0x05, 0x06, 0x03, 0x04, 0x04, 0x03, 0x05,
			0x0E, 0x0B, 0x14, 0x13, 0x13, 0x09, 0x0B, 0x06, 0x05, 0x04, 0x03, 0x02, 0x03, 0x02, 0x02, 0x02,
			0x0D, 0x07, 0x09, 0x06, 0x06, 0x04, 0x03, 0x02, 0x04, 0x03, 0x03, 0x03, 0x03, 0x03, 0x02, 0x02,
			0x09, 0x06, 0x04, 0x04, 0x04, 0x04, 0x03, 0x02, 0x03, 0x02, 0x02, 0x02, 0x02, 0x03, 0x02, 0x04,
			0x08, 0x03, 0x04, 0x07, 0x09, 0x05, 0x03, 0x03, 0x03, 0x03, 0x02, 0x02, 0x02, 0x03, 0x02, 0x02,
			0x03, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x02, 0x01, 0x02, 0x02,
			0x06, 0x0A, 0x08, 0x08, 0x06, 0x07, 0x04, 0x03, 0x04, 0x04, 0x02, 0x02, 0x04, 0x02, 0x03, 0x03,
			0x04, 0x03, 0x07, 0x07, 0x09, 0x06, 0x04, 0x03, 0x03, 0x02, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02,
			0x0A, 0x02, 0x02, 0x03, 0x02, 0x02, 0x01, 0x01, 0x02, 0x02, 0x02, 0x06, 0x03, 0x05, 0x02, 0x03,
			0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x03, 0x01, 0x01, 0x01,
			0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x04, 0x04, 0x04, 0x07, 0x09, 0x08, 0x0C, 0x02,
			0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x03,
			0x04, 0x01, 0x02, 0x04, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01,
			0x04, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x01, 0x01, 0x02, 0x02, 0x02, 0x06, 0x4B,
		}, {
			// Compression type 2 //nolint:dupl
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x27, 0x00, 0x00, 0x23, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0xFF, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x01, 0x01, 0x06, 0x0E, 0x10, 0x04,
			0x06, 0x08, 0x05, 0x04, 0x04, 0x03, 0x03, 0x02, 0x02, 0x03, 0x03, 0x01, 0x01, 0x02, 0x01, 0x01,
			0x01, 0x04, 0x02, 0x04, 0x02, 0x02, 0x02, 0x01, 0x01, 0x04, 0x01, 0x01, 0x02, 0x03, 0x03, 0x02,
			0x03, 0x01, 0x03, 0x06, 0x04, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x02, 0x01, 0x01,
			0x01, 0x29, 0x07, 0x16, 0x12, 0x40, 0x0A, 0x0A, 0x11, 0x25, 0x01, 0x03, 0x17, 0x10, 0x26, 0x2A,
			0x10, 0x01, 0x23, 0x23, 0x2F, 0x10, 0x06, 0x07, 0x02, 0x09, 0x01, 0x01, 0x01, 0x01, 0x01,
		}, { //nolint:dupl we're not interested in duplicates here
			// Compression type 3 //nolint:dupl
			0xFF, 0x0B, 0x07, 0x05, 0x0B, 0x02, 0x02, 0x02, 0x06, 0x02, 0x02, 0x01, 0x04, 0x02, 0x01, 0x03,
			0x09, 0x01, 0x01, 0x01, 0x03, 0x04, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01,
			0x05, 0x01, 0x01, 0x01, 0x0D, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x02, 0x01, 0x01, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x01,
			0x0A, 0x04, 0x02, 0x01, 0x06, 0x03, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x01,
			0x05, 0x02, 0x03, 0x04, 0x03, 0x03, 0x03, 0x02, 0x01, 0x01, 0x01, 0x02, 0x01, 0x02, 0x03, 0x03,
			0x01, 0x03, 0x01, 0x01, 0x02, 0x05, 0x01, 0x01, 0x04, 0x03, 0x05, 0x01, 0x03, 0x01, 0x03, 0x03,
			0x02, 0x01, 0x04, 0x03, 0x0A, 0x06, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x02, 0x02, 0x01, 0x0A, 0x02, 0x05, 0x01, 0x01, 0x02, 0x07, 0x02, 0x17, 0x01, 0x05, 0x01, 0x01,
			0x0E, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x06, 0x02, 0x01, 0x04, 0x05, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01,
			0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
			0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x07, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x01,
			0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x11,
		}, { // Compression type 4 //nolint:dupl
			0xFF, 0xFB, 0x98, 0x9A, 0x84, 0x85, 0x63, 0x64, 0x3E, 0x3E, 0x22, 0x22, 0x13, 0x13, 0x18, 0x17,
		}, { // Compression type 5 //nolint:dupl
			0xFF, 0xF1, 0x9D, 0x9E, 0x9A, 0x9B, 0x9A, 0x97, 0x93, 0x93, 0x8C, 0x8E, 0x86, 0x88, 0x80, 0x82,
			0x7C, 0x7C, 0x72, 0x73, 0x69, 0x6B, 0x5F, 0x60, 0x55, 0x56, 0x4A, 0x4B, 0x40, 0x41, 0x37, 0x37,
			0x2F, 0x2F, 0x27, 0x27, 0x21, 0x21, 0x1B, 0x1C, 0x17, 0x17, 0x13, 0x13, 0x10, 0x10, 0x0D, 0x0D,
			0x0B, 0x0B, 0x09, 0x09, 0x08, 0x08, 0x07, 0x07, 0x06, 0x05, 0x05, 0x04, 0x04, 0x04, 0x19, 0x18,
		}, { //nolint:dupl we're not interested in duplicates here
			// Compression type 6
			0xC3, 0xCB, 0xF5, 0x41, 0xFF, 0x7B, 0xF7, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0xBF, 0xCC, 0xF2, 0x40, 0xFD, 0x7C, 0xF7, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x7A, 0x46,
		}, { //nolint:dupl we're not interested in duplicates here
			// Compression type 7
			0xC3, 0xD9, 0xEF, 0x3D, 0xF9, 0x7C, 0xE9, 0x1E, 0xFD, 0xAB, 0xF1, 0x2C, 0xFC, 0x5B, 0xFE, 0x17,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0xBD, 0xD9, 0xEC, 0x3D, 0xF5, 0x7D, 0xE8, 0x1D, 0xFB, 0xAE, 0xF0, 0x2C, 0xFB, 0x5C, 0xFF, 0x18,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x70, 0x6C,
		}, { // Compression type 8
			0xBA, 0xC5, 0xDA, 0x33, 0xE3, 0x6D, 0xD8, 0x18, 0xE5, 0x94, 0xDA, 0x23, 0xDF, 0x4A, 0xD1, 0x10,
			0xEE, 0xAF, 0xE4, 0x2C, 0xEA, 0x5A, 0xDE, 0x15, 0xF4, 0x87, 0xE9, 0x21, 0xF6, 0x43, 0xFC, 0x12,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0xB0, 0xC7, 0xD8, 0x33, 0xE3, 0x6B, 0xD6, 0x18, 0xE7, 0x95, 0xD8, 0x23, 0xDB, 0x49, 0xD0, 0x11,
			0xE9, 0xB2, 0xE2, 0x2B, 0xE8, 0x5C, 0xDD, 0x15, 0xF1, 0x87, 0xE7, 0x20, 0xF7, 0x44, 0xFF, 0x13,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x5F, 0x9E,
		},
	}
}

func decode(input *d2datautils.BitStream, head *linkedNode) *linkedNode {
	node := head

	for node.child0 != nil {
		bit := input.ReadBits(1)
		if bit == -1 {
			log.Fatal("unexpected end of file")
		}

		if bit == 0 {
			node = node.child0
			continue
		}

		node = node.getChild1()
	}

	return node
}

const (
	decompVal1 = 256
	decompVal2 = 257
)

func buildList(primeData []byte) *linkedNode {
	root := createLinkedNode(decompVal1, 1)
	root = root.insert(createLinkedNode(decompVal2, 1))

	for i := 0; i < len(primeData); i++ {
		if primeData[i] != 0 {
			root = root.insert(createLinkedNode(i, int(primeData[i])))
		}
	}

	return root
}

func insertNode(tail *linkedNode, decomp int) *linkedNode {
	parent := tail
	result := tail.prev // This will be the new tail after the tree is updated

	temp := createLinkedNode(parent.decompressedValue, parent.weight)
	temp.parent = parent

	newnode := createLinkedNode(decomp, 0)
	newnode.parent = parent

	parent.child0 = newnode

	tail.next = temp
	temp.prev = tail
	newnode.prev = temp
	temp.next = newnode

	adjustTree(newnode)

	// ISSUE #680: For compression type 0, adjustTree should be
	// called once for every value written and only once here
	adjustTree(newnode)

	return result
}

// This increases the weight of the new node and its antecendants
// and adjusts the tree if needed
func adjustTree(newNode *linkedNode) {
	current := newNode

	for current != nil {
		current.weight++

		var insertpoint *linkedNode

		var prev *linkedNode

		// Go backwards thru the list looking for the insertion point
		insertpoint = current

		for {
			prev = insertpoint.prev
			if prev == nil {
				break
			}

			if prev.weight >= current.weight {
				break
			}

			insertpoint = prev
		}

		// No insertion point found
		if insertpoint == current {
			current = current.parent
			continue
		}

		// The following code basically swaps insertpoint with current

		// remove insert point
		if insertpoint.prev != nil {
			insertpoint.prev.next = insertpoint.next
		}

		insertpoint.next.prev = insertpoint.prev

		// insert insertpoint after current
		insertpoint.next = current.next
		insertpoint.prev = current

		if current.next != nil {
			current.next.prev = insertpoint
		}

		current.next = insertpoint

		// remove current
		current.prev.next = current.next
		current.next.prev = current.prev

		// insert current after prev
		if prev == nil {
			log.Fatal("previous frame not defined!")
		}

		temp := prev.next
		current.next = temp
		current.prev = prev
		temp.prev = current
		prev.next = current

		// Set up parent/child links
		currentparent := current.parent
		insertparent := insertpoint.parent

		if currentparent.child0 == current {
			currentparent.child0 = insertpoint
		}

		if currentparent != insertparent && insertparent.child0 == insertpoint {
			insertparent.child0 = current
		}

		current.parent = insertparent
		insertpoint.parent = currentparent

		current = current.parent
	}
}

func buildTree(tail *linkedNode) *linkedNode {
	current := tail

	for current != nil {
		child0 := current
		child1 := current.prev

		if child1 == nil {
			break
		}

		parent := createLinkedNode(0, child0.weight+child1.weight)
		parent.child0 = child0
		child0.parent = parent
		child1.parent = parent

		current.insert(parent)
		current = current.prev.prev
	}

	return current
}

// HuffmanDecompress decompresses huffman-compressed data
//nolint:gomnd // binary decode magic
func HuffmanDecompress(data []byte) []byte {
	comptype := data[0]
	primes := getPrimes()

	if comptype == 0 {
		log.Panic("compression type 0 is not currently supported")
	}

	tail := buildList(primes[comptype])
	head := buildTree(tail)

	outputstream := d2datautils.CreateStreamWriter()
	bitstream := d2datautils.CreateBitStream(data[1:])

	var decoded int

Loop:
	for {
		node := decode(bitstream, head)
		decoded = node.decompressedValue
		switch decoded {
		case 256:
			break Loop
		case 257:
			newvalue := bitstream.ReadBits(8)

			outputstream.PushByte(byte(newvalue))
			tail = insertNode(tail, newvalue)
		default:
			outputstream.PushByte(byte(decoded))
		}
	}

	return outputstream.GetBytes()
}