package server

import (
	"encoding/json"
	"net/http"

	"github.com/gin-gonic/gin"
	"gorm.io/datatypes"
)

// marshalJSON converts a map to datatypes.JSON for storage. Returns nil on
// nil input so empty detail columns stay NULL-ish rather than "null".
func marshalJSON(m map[string]any) datatypes.JSON {
	if m == nil {
		return nil
	}
	b, err := json.Marshal(m)
	if err != nil {
		return datatypes.JSON([]byte("{}"))
	}
	return b
}

// bind parses the JSON request body into out and writes a 400 on failure.
// Returns false (and aborts) when the body is invalid so callers can early-return.
func bind(c *gin.Context, out any) bool {
	if err := c.ShouldBindJSON(out); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return false
	}
	return true
}

// jsonRaw marshals v to datatypes.JSON for storage in a JSON column.
func jsonRaw(v any) datatypes.JSON {
	b, err := json.Marshal(v)
	if err != nil {
		return datatypes.JSON([]byte("null"))
	}
	return b
}

// jsonUnmarshal decodes a datatypes.JSON value into out.
func jsonUnmarshal(raw datatypes.JSON, out any) error {
	if len(raw) == 0 {
		return nil
	}
	return json.Unmarshal(raw, out)
}