package object

import (
	"github.com/inkyblackness/hacked/ss1"
	"github.com/inkyblackness/hacked/ss1/serial"
)

const (
	errInvalidClass    ss1.StringError = "invalid class"
	errInvalidSubclass ss1.StringError = "invalid subclass"
	errInvalidType     ss1.StringError = "invalid type"
)

// PropertiesTable is a collection of class-specific properties.
type PropertiesTable []ClassProperties

// ClassProperties is a collection of subclass-specific properties.
type ClassProperties []SubclassProperties

// SubclassProperties is a collection of type-specific properties.
type SubclassProperties []Properties

// Properties contains the object-specific properties.
type Properties struct {
	Common   CommonProperties
	Generic  []byte
	Specific []byte
}

// Clone returns a fresh instance with a copy of the data.
func (prop Properties) Clone() Properties {
	cloneBytes := func(in []byte) []byte {
		out := make([]byte, len(in))
		copy(out, in)
		return out
	}
	return Properties{
		Common:   prop.Common,
		Generic:  cloneBytes(prop.Generic),
		Specific: cloneBytes(prop.Specific),
	}
}

// NewPropertiesTable returns a new instance based on given descriptors.
func NewPropertiesTable(desc Descriptors) PropertiesTable {
	classCount := len(desc)
	table := make([]ClassProperties, classCount)
	for class := 0; class < classCount; class++ {
		classDesc := desc[class]
		subclassCount := len(classDesc.Subclasses)
		subclassProperties := make([]SubclassProperties, subclassCount)
		table[class] = subclassProperties
		for subclass := 0; subclass < subclassCount; subclass++ {
			subclassDesc := classDesc.Subclasses[subclass]
			typeProperties := make([]Properties, subclassDesc.TypeCount)
			subclassProperties[subclass] = typeProperties
			for objType := 0; objType < subclassDesc.TypeCount; objType++ {
				prop := &typeProperties[objType]
				prop.Generic = make([]byte, classDesc.GenericDataSize)
				prop.Specific = make([]byte, subclassDesc.SpecificDataSize)
			}
		}
	}
	return table
}

// ForObject returns the object-specific properties by given triple.
func (table PropertiesTable) ForObject(triple Triple) (*Properties, error) {
	if int(triple.Class) >= len(table) {
		return nil, errInvalidClass
	}
	classEntry := table[triple.Class]
	if int(triple.Subclass) >= len(classEntry) {
		return nil, errInvalidSubclass
	}
	subclassEntry := classEntry[triple.Subclass]
	if int(triple.Type) >= len(subclassEntry) {
		return nil, errInvalidType
	}
	return &subclassEntry[triple.Type], nil
}

// Code serializes the table with given coder.
func (table PropertiesTable) Code(coder serial.Coder) {
	version := propertiesFileVersion
	coder.Code(&version)
	for _, subclasses := range table {
		for _, types := range subclasses {
			for _, prop := range types {
				coder.Code(prop.Generic)
			}
		}
		for _, types := range subclasses {
			for _, prop := range types {
				coder.Code(prop.Specific)
			}
		}
	}
	for _, subclasses := range table {
		for _, types := range subclasses {
			for objType := 0; objType < len(types); objType++ {
				coder.Code(&types[objType].Common)
			}
		}
	}
}

// TriplesInClass returns all triples that are available in the given class.
func (table PropertiesTable) TriplesInClass(class Class) []Triple {
	var triples []Triple
	if int(class) < len(table) {
		subclasses := table[class]
		for subclass, types := range subclasses {
			for objType := range types {
				triples = append(triples, TripleFrom(int(class), subclass, objType))
			}
		}
	}
	return triples
}

// TripleIndex returns the linear index of the given index.
func (table PropertiesTable) TripleIndex(triple Triple) int {
	if int(triple.Class) >= len(table) {
		return -1
	}
	counter := 0
	for class := Class(0); class < triple.Class; class++ {
		subclasses := table[class]
		for _, types := range subclasses {
			counter += len(types)
		}
	}
	subclasses := table[triple.Class]
	if int(triple.Subclass) >= len(subclasses) {
		return -1
	}
	for subclass := Subclass(0); subclass < triple.Subclass; subclass++ {
		counter += len(subclasses[subclass])
	}
	types := subclasses[triple.Subclass]
	if int(triple.Type) >= len(types) {
		return -1
	}
	return counter + int(triple.Type)
}

// Iterate walks through all types sequentially and gives the properties to the given consumer.
// The iteration stops when the consumer returns false or the table has been exhausted.
func (table PropertiesTable) Iterate(consumer func(Triple, *Properties) bool) {
	for class, subclasses := range table {
		for subclass, types := range subclasses {
			for objType := 0; objType < len(types); objType++ {
				if !consumer(TripleFrom(class, subclass, objType), &types[objType]) {
					return
				}
			}
		}
	}
}