package format

import (
	"fmt"
	"reflect"
	"sort"
	"strconv"
	"strings"

	"github.com/nicholas-fedor/shoutrrr/pkg/types"
	"github.com/nicholas-fedor/shoutrrr/pkg/util"
)

// NodeTokenType is used to represent the type of value that a node has for syntax highlighting.
type NodeTokenType int

const (
	// UnknownToken represents all unknown/unspecified tokens.
	UnknownToken NodeTokenType = iota
	// NumberToken represents all numbers.
	NumberToken
	// StringToken represents strings and keys.
	StringToken
	// EnumToken represents enum values.
	EnumToken
	// TrueToken represent boolean true.
	TrueToken
	// FalseToken represent boolean false.
	FalseToken
	// PropToken represent a serializable struct prop.
	PropToken
	// ErrorToken represent a value that was not serializable or otherwise invalid.
	ErrorToken
	// ContainerToken is used for Array/Slice and Map tokens.
	ContainerToken
)

// Constants for number bases.
const (
	BaseDecimalLen = 10
	BaseHexLen     = 16
)

// Node is the generic config tree item.
type Node interface {
	Field() *FieldInfo
	TokenType() NodeTokenType
	Update(tv reflect.Value)
}

// ValueNode is a Node without any child items.
type ValueNode struct {
	*FieldInfo
	Value     string
	tokenType NodeTokenType
}

// Field returns the inner FieldInfo.
func (n *ValueNode) Field() *FieldInfo {
	return n.FieldInfo
}

// TokenType returns a NodeTokenType that matches the value.
func (n *ValueNode) TokenType() NodeTokenType {
	return n.tokenType
}

// Update updates the value string from the provided value.
func (n *ValueNode) Update(tv reflect.Value) {
	value, token := getValueNodeValue(tv, n.FieldInfo)
	n.Value = value
	n.tokenType = token
}

// ContainerNode is a Node with child items.
type ContainerNode struct {
	*FieldInfo
	Items        []Node
	MaxKeyLength int
}

// Field returns the inner FieldInfo.
func (n *ContainerNode) Field() *FieldInfo {
	return n.FieldInfo
}

// TokenType always returns ContainerToken for ContainerNode.
func (n *ContainerNode) TokenType() NodeTokenType {
	return ContainerToken
}

// Update updates the items to match the provided value.
func (n *ContainerNode) Update(tv reflect.Value) {
	switch n.Type.Kind() {
	case reflect.Array, reflect.Slice:
		n.updateArrayNode(tv)
	case reflect.Map:
		n.updateMapNode(tv)
	case reflect.Invalid,
		reflect.Bool,
		reflect.Int,
		reflect.Int8,
		reflect.Int16,
		reflect.Int32,
		reflect.Int64,
		reflect.Uint,
		reflect.Uint8,
		reflect.Uint16,
		reflect.Uint32,
		reflect.Uint64,
		reflect.Uintptr,
		reflect.Float32,
		reflect.Float64,
		reflect.Complex64,
		reflect.Complex128,
		reflect.Chan,
		reflect.Func,
		reflect.Interface,
		reflect.Pointer,
		reflect.String,
		reflect.Struct,
		reflect.UnsafePointer:
		// No-op for unsupported kinds
	default:
		// No-op for any remaining kinds
	}
}

func (n *ContainerNode) updateArrayNode(arrayValue reflect.Value) {
	itemCount := arrayValue.Len()
	n.Items = make([]Node, 0, itemCount)

	elemType := arrayValue.Type().Elem()

	for i := range itemCount {
		key := strconv.Itoa(i)
		val := arrayValue.Index(i)
		n.Items = append(n.Items, getValueNode(val, &FieldInfo{
			Name: key,
			Type: elemType,
		}))
	}
}

func getArrayNode(arrayValue reflect.Value, fieldInfo *FieldInfo) *ContainerNode {
	node := &ContainerNode{
		FieldInfo:    fieldInfo,
		MaxKeyLength: 0,
	}
	node.updateArrayNode(arrayValue)

	return node
}

func sortNodeItems(nodeItems []Node) {
	sort.Slice(nodeItems, func(i, j int) bool {
		return nodeItems[i].Field().Name < nodeItems[j].Field().Name
	})
}

func (n *ContainerNode) updateMapNode(mapValue reflect.Value) {
	base := n.Base
	if base == 0 {
		base = BaseDecimalLen
	}

	elemType := mapValue.Type().Elem()
	mapKeys := mapValue.MapKeys()
	nodeItems := make([]Node, len(mapKeys))
	maxKeyLength := 0

	for i, keyVal := range mapKeys {
		// The keys will always be strings
		key := keyVal.String()
		val := mapValue.MapIndex(keyVal)
		nodeItems[i] = getValueNode(val, &FieldInfo{
			Name: key,
			Type: elemType,
			Base: base,
		})
		maxKeyLength = util.Max(len(key), maxKeyLength)
	}

	sortNodeItems(nodeItems)

	n.Items = nodeItems
	n.MaxKeyLength = maxKeyLength
}

func getMapNode(mapValue reflect.Value, fieldInfo *FieldInfo) *ContainerNode {
	if mapValue.Kind() == reflect.Ptr {
		mapValue = mapValue.Elem()
	}

	node := &ContainerNode{
		FieldInfo: fieldInfo,
	}
	node.updateMapNode(mapValue)

	return node
}

func getNode(fieldVal reflect.Value, fieldInfo *FieldInfo) Node {
	switch fieldInfo.Type.Kind() {
	case reflect.Array, reflect.Slice:
		return getArrayNode(fieldVal, fieldInfo)
	case reflect.Map:
		return getMapNode(fieldVal, fieldInfo)
	case reflect.Invalid,
		reflect.Bool,
		reflect.Int,
		reflect.Int8,
		reflect.Int16,
		reflect.Int32,
		reflect.Int64,
		reflect.Uint,
		reflect.Uint8,
		reflect.Uint16,
		reflect.Uint32,
		reflect.Uint64,
		reflect.Uintptr,
		reflect.Float32,
		reflect.Float64,
		reflect.Complex64,
		reflect.Complex128,
		reflect.Chan,
		reflect.Func,
		reflect.Interface,
		reflect.Pointer,
		reflect.String,
		reflect.Struct,
		reflect.UnsafePointer:
		return getValueNode(fieldVal, fieldInfo)
	default:
		return getValueNode(fieldVal, fieldInfo)
	}
}

func getRootNode(value any) *ContainerNode {
	structValue := reflect.ValueOf(value)
	if structValue.Kind() == reflect.Ptr {
		structValue = structValue.Elem()
	}

	structType := structValue.Type()

	enums := map[string]types.EnumFormatter{}
	if enummer, isEnummer := value.(types.Enummer); isEnummer {
		enums = enummer.Enums()
	}

	infoFields := getStructFieldInfo(structType, enums)
	nodeItems := make([]Node, 0, len(infoFields))
	maxKeyLength := 0

	for _, fieldInfo := range infoFields {
		fieldValue := structValue.FieldByName(fieldInfo.Name)
		if !fieldValue.IsValid() {
			fieldValue = reflect.Zero(fieldInfo.Type)
		}

		nodeItems = append(nodeItems, getNode(fieldValue, &fieldInfo))
		maxKeyLength = util.Max(len(fieldInfo.Name), maxKeyLength)
	}

	sortNodeItems(nodeItems)

	return &ContainerNode{
		FieldInfo:    &FieldInfo{Type: structType},
		Items:        nodeItems,
		MaxKeyLength: maxKeyLength,
	}
}

func getValueNode(fieldVal reflect.Value, fieldInfo *FieldInfo) *ValueNode {
	value, tokenType := getValueNodeValue(fieldVal, fieldInfo)

	return &ValueNode{
		FieldInfo: fieldInfo,
		Value:     value,
		tokenType: tokenType,
	}
}

func getValueNodeValue(fieldValue reflect.Value, fieldInfo *FieldInfo) (string, NodeTokenType) {
	kind := fieldValue.Kind()

	base := fieldInfo.Base
	if base == 0 {
		base = BaseDecimalLen
	}

	if fieldInfo.IsEnum() {
		return fieldInfo.EnumFormatter.Print(int(fieldValue.Int())), EnumToken
	}

	switch kind {
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		val := strconv.FormatUint(fieldValue.Uint(), base)
		if base == BaseHexLen {
			val = "0x" + val
		}

		return val, NumberToken
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return strconv.FormatInt(fieldValue.Int(), base), NumberToken
	case reflect.String:
		return fieldValue.String(), StringToken
	case reflect.Bool:
		val := fieldValue.Bool()
		if val {
			return PrintBool(val), TrueToken
		}

		return PrintBool(val), FalseToken
	case reflect.Array, reflect.Slice, reflect.Map:
		return getContainerValueString(fieldValue, fieldInfo), UnknownToken
	case reflect.Ptr, reflect.Struct:
		if val, err := GetConfigPropString(fieldValue); err == nil {
			return val, PropToken
		}

		return "<ERR>", ErrorToken
	case reflect.Invalid,
		reflect.Uintptr,
		reflect.Float32,
		reflect.Float64,
		reflect.Complex64,
		reflect.Complex128,
		reflect.Chan,
		reflect.Func,
		reflect.Interface,
		reflect.UnsafePointer:
		return fmt.Sprintf("<?%s>", kind.String()), UnknownToken
	default:
		return fmt.Sprintf("<?%s>", kind.String()), UnknownToken
	}
}

func getContainerValueString(fieldValue reflect.Value, fieldInfo *FieldInfo) string {
	itemSeparator := fieldInfo.ItemSeparator
	sliceLength := fieldValue.Len()

	var mapKeys []reflect.Value
	if fieldInfo.Type.Kind() == reflect.Map {
		mapKeys = fieldValue.MapKeys()
		sort.Slice(mapKeys, func(a, b int) bool {
			return mapKeys[a].String() < mapKeys[b].String()
		})
	}

	stringBuilder := strings.Builder{}

	var itemFieldInfo *FieldInfo

	for i := range sliceLength {
		var itemValue reflect.Value

		if i > 0 {
			stringBuilder.WriteRune(itemSeparator)
		}

		if mapKeys != nil {
			mapKey := mapKeys[i]
			stringBuilder.WriteString(mapKey.String())
			stringBuilder.WriteRune(':')

			itemValue = fieldValue.MapIndex(mapKey)
		} else {
			itemValue = fieldValue.Index(i)
		}

		if i == 0 {
			itemFieldInfo = &FieldInfo{
				Type: itemValue.Type(),
				// Inherit the base from the container
				Base: fieldInfo.Base,
			}

			if itemFieldInfo.Base == 0 {
				itemFieldInfo.Base = BaseDecimalLen
			}
		}

		strVal, _ := getValueNodeValue(itemValue, itemFieldInfo)
		stringBuilder.WriteString(strVal)
	}

	return stringBuilder.String()
}