package yqlib

import (
	"fmt"
	"strings"

	yaml "github.com/goccy/go-yaml"
	"github.com/goccy/go-yaml/ast"
	goccyToken "github.com/goccy/go-yaml/token"
)

func (o *CandidateNode) goccyDecodeIntoChild(childNode ast.Node, cm yaml.CommentMap, anchorMap map[string]*CandidateNode) (*CandidateNode, error) {
	newChild := o.CreateChild()

	err := newChild.UnmarshalGoccyYAML(childNode, cm, anchorMap)
	return newChild, err
}

func (o *CandidateNode) UnmarshalGoccyYAML(node ast.Node, cm yaml.CommentMap, anchorMap map[string]*CandidateNode) error {
	if node.GetComment() != nil {
		commentMapComments := cm[node.GetPath()]
		for _, comment := range node.GetComment().Comments {
			for _, commentMapComment := range commentMapComments {
				commentMapValue := strings.Join(commentMapComment.Texts, "\n")
				if commentMapValue == comment.Token.Value {
					switch commentMapComment.Position {
					case yaml.CommentHeadPosition:
						o.HeadComment = comment.String()
					case yaml.CommentLinePosition:
						o.LineComment = comment.String()
					case yaml.CommentFootPosition:
						o.FootComment = comment.String()
					}
				}
			}

		}
	}

	o.Value = node.String()
	o.Line = node.GetToken().Position.Line
	o.Column = node.GetToken().Position.Column

	switch node.Type() {
	case ast.IntegerType:
		o.Kind = ScalarNode
		o.Tag = "!!int"
	case ast.FloatType:
		o.Kind = ScalarNode
		o.Tag = "!!float"
	case ast.BoolType:
		o.Kind = ScalarNode
		o.Tag = "!!bool"
	case ast.NullType:
		o.Kind = ScalarNode
		o.Tag = "!!null"
		o.Value = node.GetToken().Value
	case ast.StringType:
		o.Kind = ScalarNode
		o.Tag = "!!str"
		switch node.GetToken().Type {
		case goccyToken.SingleQuoteType:
			o.Style = SingleQuotedStyle
		case goccyToken.DoubleQuoteType:
			o.Style = DoubleQuotedStyle
		}
		o.Value = node.(*ast.StringNode).Value
	case ast.LiteralType:
		o.Kind = ScalarNode
		o.Tag = "!!str"
		o.Style = LiteralStyle
		astLiteral := node.(*ast.LiteralNode)
		if astLiteral.Start.Type == goccyToken.FoldedType {
			o.Style = FoldedStyle
		}
		// Preserving the original multiline string value is important for fidelity.
		// goccy/go-yaml provides this in astLiteral.Value.Value for literal and folded styles.
		o.Value = astLiteral.Value.Value
	case ast.TagType:
		// Recursively unmarshal the tagged value, then apply the tag to the CandidateNode.
		if err := o.UnmarshalGoccyYAML(node.(*ast.TagNode).Value, cm, anchorMap); err != nil {
			return err
		}
		o.Tag = node.(*ast.TagNode).Start.Value // Tag value includes the '!' or '!!' prefix.
	case ast.MappingType:
		o.Kind = MappingNode
		o.Tag = "!!map"

		mappingNode := node.(*ast.MappingNode)
		if mappingNode.IsFlowStyle {
			o.Style = FlowStyle
		}
		for _, mappingValueNode := range mappingNode.Values {
			err := o.goccyProcessMappingValueNode(mappingValueNode, cm, anchorMap)
			if err != nil {
				return err
			}
		}
		if mappingNode.FootComment != nil {
			o.FootComment = mappingNode.FootComment.String()
		}
	case ast.MappingValueType:
		o.Kind = MappingNode
		o.Tag = "!!map"
		mappingValueNode := node.(*ast.MappingValueNode)
		err := o.goccyProcessMappingValueNode(mappingValueNode, cm, anchorMap)
		if err != nil {
			return err
		}
	case ast.SequenceType:
		o.Kind = SequenceNode
		o.Tag = "!!seq"
		sequenceNode := node.(*ast.SequenceNode)
		if sequenceNode.IsFlowStyle {
			o.Style = FlowStyle
		}
		astSeq := sequenceNode.Values
		o.Content = make([]*CandidateNode, len(astSeq))
		for i := 0; i < len(astSeq); i++ {
			keyNode := o.CreateChild()
			keyNode.IsMapKey = true
			keyNode.Tag = "!!int"
			keyNode.Kind = ScalarNode
			keyNode.Value = fmt.Sprintf("%v", i)

			valueNode, err := o.goccyDecodeIntoChild(astSeq[i], cm, anchorMap)
			if err != nil {
				return err
			}

			valueNode.Key = keyNode
			o.Content[i] = valueNode
		}
	case ast.AnchorType:
		anchorNode := node.(*ast.AnchorNode)
		err := o.UnmarshalGoccyYAML(anchorNode.Value, cm, anchorMap)
		if err != nil {
			return err
		}
		o.Anchor = anchorNode.Name.String()
		anchorMap[o.Anchor] = o

	case ast.AliasType:
		aliasNode := node.(*ast.AliasNode)
		o.Kind = AliasNode
		o.Value = aliasNode.Value.String()
		o.Alias = anchorMap[o.Value]

	case ast.MergeKeyType:
		o.Kind = ScalarNode
		o.Tag = "!!merge"
		o.Value = "<<"

	default:
		log.Debugf("UnmarshalYAML -  no idea of the type!!\n%v: %v", node.Type(), node.String())
	}
	log.Debugf("KIND: %v", o.Kind)
	return nil
}

func (o *CandidateNode) goccyProcessMappingValueNode(mappingEntry *ast.MappingValueNode, cm yaml.CommentMap, anchorMap map[string]*CandidateNode) error {
	log.Debug("UnmarshalYAML MAP KEY entry %v", mappingEntry.Key)

	// AddKeyValueFirst because it clones the nodes, and we want to have the real refs when Unmarshalling
	// particularly for the anchorMap
	keyNode, valueNode := o.AddKeyValueChild(&CandidateNode{}, &CandidateNode{})

	if err := keyNode.UnmarshalGoccyYAML(mappingEntry.Key, cm, anchorMap); err != nil {
		return err
	}

	log.Debug("UnmarshalYAML MAP VALUE entry %v", mappingEntry.Value)
	if err := valueNode.UnmarshalGoccyYAML(mappingEntry.Value, cm, anchorMap); err != nil {
		return err
	}

	if mappingEntry.FootComment != nil {
		valueNode.FootComment = mappingEntry.FootComment.String()
	}

	return nil
}

func (o *CandidateNode) MarshalGoccyYAML() (interface{}, error) {
	log.Debug("MarshalGoccyYAML to goccy: %v", o.Tag)

	switch o.Kind {
	case AliasNode:
		log.Debug("MarshalGoccyYAML - alias to goccy: %v", o.Tag)
		// For goccy, we'll return the referenced value directly
		// The goccy encoder will handle alias creation
		if o.Alias != nil {
			return o.Alias.MarshalGoccyYAML()
		}
		return o.Value, nil

	case ScalarNode:
		// Handle different scalar types based on tag for correct marshalling.
		switch o.Tag {
		case "!!int":
			val, err := parseInt(o.Value)
			if err == nil {
				return val, nil
			}

			return nil, fmt.Errorf("cannot marshal node %s as int: %w", NodeToString(o), err)
		case "!!float":
			val, err := parseFloat(o.Value)
			if err == nil {
				return val, nil
			}

			return nil, fmt.Errorf("cannot marshal node %s as float: %w", NodeToString(o), err)
		case "!!bool":
			val, err := parseBool(o.Value)
			if err == nil {
				return val, nil
			}

			return nil, fmt.Errorf("cannot marshal node %s as bool: %w", NodeToString(o), err)
		case "!!null":
			// goccy/go-yaml expects a nil interface{} for null values.
			return nil, nil
		default:
			// For standard strings (!!str) or unknown/custom tags, marshal as a string.
			// The goccy encoder will handle quoting and style if it's a plain string.
			// For custom tags, goccy prepends the tag if the value is a string.
			return o.Value, nil
		}

	case MappingNode:
		log.Debug("MarshalGoccyYAML - mapping: %v", NodeToString(o))
		// Ensure even number of children for key-value pairs
		if len(o.Content)%2 != 0 {
			return nil, fmt.Errorf("mapping node at %s has an odd number of children (%d), malformed key-value pairs", NodeToString(o), len(o.Content))
		}
		result := make(map[string]interface{})

		for i := 0; i < len(o.Content); i += 2 {
			// No need to check i+1 >= len(o.Content) here due to the check above

			keyNode := o.Content[i]
			valueNode := o.Content[i+1]

			key := keyNode.Value
			if key == "" {
				key = NodeToString(keyNode)
			}

			value, err := valueNode.MarshalGoccyYAML()
			if err != nil {
				return nil, err
			}

			result[key] = value
		}
		return result, nil

	case SequenceNode:
		log.Debug("MarshalGoccyYAML - sequence: %v", NodeToString(o))
		result := make([]interface{}, len(o.Content))

		for i, childNode := range o.Content {
			value, err := childNode.MarshalGoccyYAML()
			if err != nil {
				return nil, err
			}
			result[i] = value
		}
		return result, nil
	}

	// Default case
	return o.Value, nil
}