feat: manually mirror opencoze's code from bytedance

Change-Id: I09a73aadda978ad9511264a756b2ce51f5761adf

backend/infra/impl/document/parser/builtin/parse_json.go

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2025 coze-dev Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package builtin
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/cloudwego/eino/components/document/parser"
+	"github.com/cloudwego/eino/schema"
+
+	contract "github.com/coze-dev/coze-studio/backend/infra/contract/document/parser"
+)
+
+func parseJSON(config *contract.Config) parseFn {
+	return func(ctx context.Context, reader io.Reader, opts ...parser.Option) (docs []*schema.Document, err error) {
+		b, err := io.ReadAll(reader)
+		if err != nil {
+			return nil, err
+		}
+
+		var rawSlices []map[string]string
+		if err = json.Unmarshal(b, &rawSlices); err != nil {
+			return nil, err
+		}
+
+		if len(rawSlices) == 0 {
+			return nil, fmt.Errorf("[parseJSON] json data is empty")
+		}
+
+		var header []string
+		if config.ParsingStrategy.IsAppend {
+			for _, col := range config.ParsingStrategy.Columns {
+				header = append(header, col.Name)
+			}
+		} else {
+			for k := range rawSlices[0] {
+				// init 取首个 json item 中 key 的随机顺序
+				header = append(header, k)
+			}
+		}
+
+		iter := &jsonIterator{
+			header: header,
+			rows:   rawSlices,
+			i:      0,
+		}
+
+		return parseByRowIterator(iter, config, opts...)
+	}
+}
+
+type jsonIterator struct {
+	header []string
+	rows   []map[string]string
+	i      int
+}
+
+func (j *jsonIterator) NextRow() (row []string, end bool, err error) {
+	if j.i == 0 {
+		j.i++
+		return j.header, false, nil
+	}
+
+	if j.i == len(j.rows)+1 {
+		return nil, true, nil
+	}
+
+	raw := j.rows[j.i-1]
+	j.i++
+	for _, h := range j.header {
+		val, found := raw[h]
+		if !found {
+			row = append(row, "")
+		} else {
+			row = append(row, val)
+		}
+	}
+
+	return row, false, nil
+}