package openapi

import (
	"encoding/json"
	"git.yuntuo.hk/k2safe/go-omni/response"
	"sort"
	"strings"
)

// EnvelopeWith describes the same configurable envelope used at runtime. data
// describes the business value; it is never embedded under a fixed field name.
// A nil data schema describes an error response and selects ErrorBody if set.
func EnvelopeWith(data *Schema, cfg response.Config) (*Schema, error) {
	f, err := response.New(cfg)
	if err != nil {
		return nil, err
	}
	c := f.Config()
	body := c.Body
	if data == nil && c.ErrorBody != nil {
		body = c.ErrorBody
	}
	if body != nil {
		return templateSchema(body, data, c), nil
	}
	s := &Schema{Type: "object", Properties: map[string]*Schema{}}
	if c.CodeField != "-" {
		s.Properties[c.CodeField] = codeSchema(c.CodeType)
		s.Required = append(s.Required, c.CodeField)
	}
	if c.MessageField != "-" {
		s.Properties[c.MessageField] = &Schema{Type: "string"}
		s.Required = append(s.Required, c.MessageField)
	}
	if c.RequestIDField != "-" {
		s.Properties[c.RequestIDField] = &Schema{Type: "string"}
	}
	if c.DataField != "-" && (data != nil || c.DataMode == "always") {
		if data == nil {
			data = &Schema{Type: "object", Nullable: true, Enum: []any{nil}}
		}
		s.Properties[c.DataField] = data
		s.Required = append(s.Required, c.DataField)
	}
	return s, nil
}

func templateSchema(value any, data *Schema, cfg response.Config) *Schema {
	switch response.Slot(value) {
	case "code":
		return codeSchema(cfg.CodeType)
	case "message", "requestId":
		return &Schema{Type: "string"}
	case "ok":
		return &Schema{Type: "boolean"}
	case "status":
		return &Schema{Type: "integer"}
	case "data":
		if data != nil {
			return data
		}
		return &Schema{Type: "object", Nullable: true, Enum: []any{nil}}
	}
	switch v := value.(type) {
	case map[string]any:
		s := &Schema{Type: "object", Properties: map[string]*Schema{}}
		keys := make([]string, 0, len(v))
		for key := range v {
			keys = append(keys, key)
		}
		sort.Strings(keys)
		for _, key := range keys {
			item := v[key]
			if response.Slot(item) == "data" && data == nil && cfg.DataMode != "always" {
				continue
			}
			s.Properties[key] = templateSchema(item, data, cfg)
			if response.Slot(item) != "requestId" {
				s.Required = append(s.Required, key)
			}
		}
		return s
	case []any:
		items := &Schema{}
		for _, item := range v {
			items.AnyOf = append(items.AnyOf, templateSchema(item, data, cfg))
		}
		size := len(v)
		return &Schema{Type: "array", Items: items, MinItems: &size, MaxItems: &size}
	case string:
		if strings.HasPrefix(v, "$${") {
			v = v[1:]
		}
		return &Schema{Type: "string", Enum: []any{v}}
	case bool:
		return &Schema{Type: "boolean", Enum: []any{v}}
	case nil:
		return &Schema{Type: "object", Nullable: true, Enum: []any{nil}}
	default:
		typeName := "number"
		encoded, _ := json.Marshal(v)
		if _, err := json.Number(string(encoded)).Int64(); err == nil {
			typeName = "integer"
		}
		return &Schema{Type: typeName, Enum: []any{v}}
	}
}

func codeSchema(kind string) *Schema {
	if kind == "int32" || kind == "int64" {
		return &Schema{Type: "integer", Format: kind}
	}
	return &Schema{Type: kind}
}