package main

import (
	"bytes"
	"encoding/json"
	"io"
)

// exactFields 验证精确字段集合；原文重复键、大小写别名和尾随JSON均拒绝。
func exactFields(raw json.RawMessage, names ...string) (map[string]json.RawMessage, bool) {
	decoder := json.NewDecoder(bytes.NewReader(raw))
	token, err := decoder.Token()
	if err != nil || token != json.Delim('{') {
		return nil, false
	}
	fields := make(map[string]json.RawMessage, len(names))
	for decoder.More() {
		token, err = decoder.Token()
		if err != nil {
			return nil, false
		}
		key, ok := token.(string)
		if !ok {
			return nil, false
		}
		allowed := false
		for _, name := range names {
			allowed = allowed || name == key
		}
		if !allowed {
			return nil, false
		}
		if _, exists := fields[key]; exists {
			return nil, false
		}
		var value json.RawMessage
		if decoder.Decode(&value) != nil || bytes.Equal(bytes.TrimSpace(value), []byte("null")) {
			return nil, false
		}
		fields[key] = value
	}
	if _, err = decoder.Token(); err != nil {
		return nil, false
	}
	var tail any
	return fields, len(fields) == len(names) && decoder.Decode(&tail) == io.EOF
}
func decodePayload(raw json.RawMessage) (workflowPayload, bool) {
	fields, ok := exactFields(raw, "run_id", "sequence")
	var out workflowPayload
	if !ok || json.Unmarshal(fields["run_id"], &out.RunID) != nil || json.Unmarshal(fields["sequence"], &out.Sequence) != nil {
		return out, false
	}
	return out, true
}
func matchesOutput(raw json.RawMessage, runID string, sequence int) bool {
	fields, ok := exactFields(raw, "left", "right")
	if !ok {
		return false
	}
	left, ok := decodePayload(fields["left"])
	right, ok2 := decodePayload(fields["right"])
	return ok && ok2 && left == (workflowPayload{RunID: runID, Sequence: sequence}) && right == left
}