package yaml_checker

import (
	"github.com/pkg/errors"
	"gopkg.in/yaml.v3"
	"os"
)

const (
	schemaNodeTypeObject = "object"
	schemaNodeTypeField  = "field"
)

type SchemaDoc struct {
	rootSchemas []SchemaNode
}

type SchemaDocYaml struct {
	RootSchemas []SchemaYaml `yaml:"schema"`
}

type SchemaYaml struct {
	Type     string `yaml:"type"`
	Name     string `yaml:"name"`
	Describe string `yaml:"describe"`
	Required bool   `yaml:"required"`
	AsArray  bool   `yaml:"as_array"`

	// object
	Fields []SchemaYaml `yaml:"fields"`

	// field
	FieldType string `yaml:"field_type"`
}

func NewSchemaDoc(schemaFilePath string) (*SchemaDoc, error) {
	if isStringEmpty(schemaFilePath) || !pathExists(schemaFilePath) {
		return nil, errors.New("schema文件不存在")
	}

	validatorFileBytes, err := os.ReadFile(schemaFilePath)
	if err != nil {
		return nil, errors.New("读取schema文件错误: " + err.Error())
	}

	schemaDocYaml := new(SchemaDocYaml)
	err = yaml.Unmarshal(validatorFileBytes, schemaDocYaml)
	if err != nil {
		return nil, errors.New("schema文件unmarshal错误: " + err.Error())
	}

	if schemaDocYaml.RootSchemas == nil || len(schemaDocYaml.RootSchemas) == 0 {
		return nil, errors.New("schema文件结构错误: 没有根节点")
	}

	doc := new(SchemaDoc)
	for _, rootSchema := range schemaDocYaml.RootSchemas {
		rootSchemaNode, err := newSchemaNode(&rootSchema)
		if err != nil {
			return nil, err
		}

		doc.rootSchemas = append(doc.rootSchemas, rootSchemaNode)
	}

	return doc, nil
}

func newSchemaNode(schemaNodeYaml *SchemaYaml) (SchemaNode, error) {
	switch schemaNodeYaml.Type {
	case schemaNodeTypeObject:
		return newObjectSchemaNode(schemaNodeYaml)
	case schemaNodeTypeField:
		return newFieldSchemaNode(schemaNodeYaml)
	default:
		return nil, errors.New("不支持的schema节点类型")
	}
}

func newObjectSchemaNode(schemaNodeYaml *SchemaYaml) (*ObjectSchemaNode, error) {
	if schemaNodeYaml.Type != schemaNodeTypeObject {
		return nil, errors.New("schema节点类型错误: 期望类型" + schemaNodeTypeObject + " 实际类型" + schemaNodeYaml.Type)
	}

	if isStringEmpty(schemaNodeYaml.Name) {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有name属性")
	}

	if isStringEmpty(schemaNodeYaml.Describe) {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有describe属性")
	}

	if schemaNodeYaml.Fields == nil || len(schemaNodeYaml.Fields) == 0 {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有fields属性")
	}

	fieldSchemaNodes := make([]SchemaNode, 0)
	for _, field := range schemaNodeYaml.Fields {
		fieldSchemaNode, err := newSchemaNode(&field)
		if err != nil {
			return nil, err
		}

		fieldSchemaNodes = append(fieldSchemaNodes, fieldSchemaNode)
	}

	return &ObjectSchemaNode{
		BaseNamingSchemaNode: BaseNamingSchemaNode{
			Type:     schemaNodeYaml.Type,
			Name:     schemaNodeYaml.Name,
			Describe: schemaNodeYaml.Describe,
			Required: schemaNodeYaml.Required,
		},
		AsArray: schemaNodeYaml.AsArray,
		Fields:  fieldSchemaNodes,
	}, nil
}

func newFieldSchemaNode(schemaNodeYaml *SchemaYaml) (*FieldSchemaNode, error) {
	if schemaNodeYaml.Type != schemaNodeTypeField {
		return nil, errors.New("schema节点类型错误: 期望类型" + schemaNodeTypeField + " 实际类型" + schemaNodeYaml.Type)
	}

	if isStringEmpty(schemaNodeYaml.Name) {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有name属性")
	}

	if isStringEmpty(schemaNodeYaml.Describe) {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有describe属性")
	}

	if isStringEmpty(schemaNodeYaml.FieldType) {
		return nil, errors.New(schemaNodeTypeObject + "schema类型必须有field_type属性")
	}

	return &FieldSchemaNode{
		BaseNamingSchemaNode: BaseNamingSchemaNode{
			Type:     schemaNodeYaml.Type,
			Name:     schemaNodeYaml.Name,
			Describe: schemaNodeYaml.Describe,
			Required: schemaNodeYaml.Required,
		},
		AsArray:   schemaNodeYaml.AsArray,
		FieldType: schemaNodeYaml.FieldType,
	}, nil
}

func (schemaDoc *SchemaDoc) ValidateFile(filePath string) error {
	if !pathExists(filePath) {
		return errors.New("文件不存在: " + filePath)
	}

	fileBytes, err := os.ReadFile(filePath)
	if err != nil {
		return errors.New("读取文件错误: " + err.Error())
	}

	yamlMap := make(map[string]any)
	err = yaml.Unmarshal(fileBytes, yamlMap)
	if err != nil {
		return errors.New("unmarshal文件错误: " + err.Error())
	}

	return schemaDoc.validate(yamlMap)
}

func (schemaDoc *SchemaDoc) ValidateMap(yamlMap map[string]any) error {
	if yamlMap == nil || len(yamlMap) == 0 {
		return errors.New("没有yaml的map")
	}

	return schemaDoc.validate(yamlMap)
}

func (schemaDoc *SchemaDoc) validate(yamlMap map[string]any) error {
	for _, rootSchemaNode := range schemaDoc.rootSchemas {
		err := rootSchemaNode.Validate(yamlMap)
		if err != nil {
			return err
		}
	}

	return nil
}