#[cfg(test)]
mod tests {
    use super::*;
    use base64::engine::general_purpose::STANDARD as BASE64_STANDARD;
    use serde_json::json;

    #[test]
    fn request_body_normalizes_size_prompt_and_candidate_count() {
        let body = build_vector_engine_image_request_body(
            "  风雨夜里的街道  ",
            Some("  低清，水印  "),
            " 1:1 ",
            10,
            &["data:image/png;base64,AAAA".to_string()],
        );

        assert_eq!(body["model"], GPT_IMAGE_2_MODEL);
        assert_eq!(body["size"], "1024x1024");
        assert_eq!(body["n"], 4);
        assert_eq!(body["prompt"], "风雨夜里的街道\n避免：低清，水印");
        assert!(body.get("image").is_none());
    }

    #[test]
    fn provider_urls_normalize_root_and_v1_base_urls() {
        let root_settings = VectorEngineImageSettings {
            base_url: "https://vector.example".to_string(),
            api_key: "test-key".to_string(),
            request_timeout_ms: 1_000,
        };
        let v1_settings = VectorEngineImageSettings {
            base_url: "https://vector.example/v1".to_string(),
            api_key: "test-key".to_string(),
            request_timeout_ms: 1_000,
        };

        assert_eq!(
            vector_engine_images_generation_url(&root_settings),
            "https://vector.example/v1/images/generations"
        );
        assert_eq!(
            vector_engine_images_generation_url(&v1_settings),
            "https://vector.example/v1/images/generations"
        );
        assert_eq!(
            vector_engine_images_edit_url(&root_settings),
            "https://vector.example/v1/images/edits"
        );
        assert_eq!(
            vector_engine_images_edit_url(&v1_settings),
            "https://vector.example/v1/images/edits"
        );
    }

    #[test]
    fn data_url_and_base64_image_decoding_preserves_image_metadata() {
        let data_url = format!(
            "data:image/png;base64,{}",
            BASE64_STANDARD.encode(b"\x89PNG\r\n\x1A\nrest")
        );

        let reference = parse_reference_image_data_url(&data_url, 2)
            .expect("data url should parse")
            .expect("image data url should be accepted");
        assert_eq!(reference.file_name, "reference-2.png");
        assert_eq!(reference.mime_type, "image/png");
        assert_eq!(reference.bytes, b"\x89PNG\r\n\x1A\nrest");

        let image = decode_generated_image_base64(BASE64_STANDARD.encode(b"\x89PNG\r\n\x1A\nrest").as_str())
            .expect("base64 image should decode");
        assert_eq!(image.extension, "png");
        assert_eq!(image.mime_type, "image/png");
        assert_eq!(image.bytes, b"\x89PNG\r\n\x1A\nrest");
    }

    #[test]
    fn error_status_hints_and_audit_fields_are_structured() {
        let audit = PlatformImageFailureAudit {
            provider: VECTOR_ENGINE_PROVIDER,
            endpoint: "https://vector.example/v1/images/generations".to_string(),
            operation: "图片生成失败".to_string(),
            failure_stage: "upstream_status",
            status_code: Some(504),
            status_class: Some("5xx"),
            timeout: true,
            retryable: true,
            error_message: "上游超时".to_string(),
            error_source: Some("read timeout".to_string()),
            raw_excerpt: Some("{\"error\":\"timeout\"}".to_string()),
            latency_ms: Some(987),
            prompt_chars: Some(64),
            reference_image_count: Some(2),
            image_model: Some(VECTOR_ENGINE_GPT_IMAGE_2_MODEL),
        };

        let request_error = PlatformImageError::Request {
            provider: VECTOR_ENGINE_PROVIDER,
            message: "请求发送失败".to_string(),
            endpoint: Some("https://vector.example/v1/images/generations".to_string()),
            timeout: true,
            connect: false,
            request: true,
            body: false,
            status_code: None,
            source: None,
            audit: None,
        };
        let invalid_config = PlatformImageError::InvalidConfig {
            provider: VECTOR_ENGINE_PROVIDER,
            message: "缺少配置".to_string(),
        };
        let invalid_request = PlatformImageError::InvalidRequest {
            provider: VECTOR_ENGINE_PROVIDER,
            message: "请求不合法".to_string(),
        };
        let upstream_timeout = PlatformImageError::Upstream {
            provider: VECTOR_ENGINE_PROVIDER,
            message: "upstream timeout".to_string(),
            upstream_status: 502,
            raw_excerpt: "deadline has elapsed".to_string(),
            audit: Some(audit.clone()),
        };

        assert_eq!(invalid_config.status_hint(), PlatformImageStatusHint::ServiceUnavailable);
        assert_eq!(invalid_request.status_hint(), PlatformImageStatusHint::BadRequest);
        assert_eq!(request_error.status_hint(), PlatformImageStatusHint::GatewayTimeout);
        assert_eq!(upstream_timeout.status_hint(), PlatformImageStatusHint::GatewayTimeout);
        assert_eq!(
            PlatformImageError::MissingImage {
                provider: VECTOR_ENGINE_PROVIDER,
                message: "缺图".to_string(),
                audit: Some(audit.clone()),
            }
            .status_hint(),
            PlatformImageStatusHint::BadGateway
        );

        let audit_ref = upstream_timeout.audit().expect("audit should be preserved");
        assert_eq!(audit_ref.provider, VECTOR_ENGINE_PROVIDER);
        assert_eq!(audit_ref.endpoint, "https://vector.example/v1/images/generations");
        assert_eq!(audit_ref.status_code, Some(504));
        assert_eq!(audit_ref.status_class, Some("5xx"));
        assert!(audit_ref.timeout);
        assert!(audit_ref.retryable);
        assert_eq!(audit_ref.reference_image_count, Some(2));
        assert_eq!(audit_ref.image_model, Some(VECTOR_ENGINE_GPT_IMAGE_2_MODEL));
        assert!(invalid_config.audit().is_none());
        assert!(invalid_request.audit().is_none());
    }

    #[test]
    fn extract_image_urls_and_b64_values_are_deduped() {
        let payload = json!({
            "data": [
                {"image": "https://example.com/a.png"},
                {"url": "https://example.com/a.png"},
                {"image_url": "ftp://example.com/b.png"},
                {"url": "https://example.com/b.png"}
            ],
            "nested": {
                "b64_json": ["YWJj", "ZGVm"]
            }
        });

        assert_eq!(
            extract_image_urls(&payload),
            vec![
                "https://example.com/a.png".to_string(),
                "https://example.com/b.png".to_string()
            ]
        );
        assert_eq!(
            extract_b64_images(&payload),
            vec!["YWJj".to_string(), "ZGVm".to_string()]
        );
    }
}