File size: 16,346 Bytes
9792ea7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
# -*- coding: utf-8 -*-
"""The Google Gemini embedding model.

Handles both text-only and multimodal models under a single class.
``gemini-embedding-001`` accepts ``list[str | TextBlock]``.
``gemini-embedding-2`` additionally accepts
:class:`~agentscope.message.DataBlock` (images, video, audio, PDF).
The model name determines the API call style.

Text payloads may be passed either as bare ``str`` or as
:class:`~agentscope.message.TextBlock` — the latter is unpacked to its
``.text`` field on entry so the rest of the pipeline only deals with
``str`` and ``DataBlock``.
"""
from __future__ import annotations

import asyncio
from dataclasses import dataclass
from datetime import datetime
from typing import Any

from .._cache_base import EmbeddingCacheBase
from .._embedding_response import EmbeddingResponse
from .._embedding_usage import EmbeddingUsage
from .._embedding_base import EmbeddingModelBase
from ..._logging import logger
from ...credential import CredentialBase
from ...message import DataBlock, TextBlock

#: Model name prefixes that use the multimodal API path.
_MULTIMODAL_PREFIXES = ("gemini-embedding-2",)


@dataclass
class _MultimodalLimits:
    """Per-request constraints for Gemini multimodal embedding."""

    max_elements: int = 20
    """Maximum total content elements per API call."""

    max_images: int = 6
    """Maximum image elements per API call."""

    max_videos: int = 1
    """Maximum video elements per API call."""

    max_audios: int = 1
    """Maximum audio elements per API call."""

    max_pdfs: int = 1
    """Maximum PDF documents per API call."""


_MODEL_LIMITS: dict[str, _MultimodalLimits] = {
    "gemini-embedding-2": _MultimodalLimits(
        max_elements=20,
        max_images=6,
        max_videos=1,
        max_audios=1,
        max_pdfs=1,
    ),
}

_DEFAULT_LIMITS = _MultimodalLimits()


class GeminiEmbeddingModel(EmbeddingModelBase[str | TextBlock | DataBlock]):
    """Unified Google Gemini embedding model.

    Routes to the text-only or multimodal Gemini API based on the
    model name.

    - **Text mode** (``gemini-embedding-001``): uses the base class's
      simple batch splitting + concurrent retry.  The Gemini API
      accepts a list of strings and returns individual embeddings.
    - **Multimodal mode** (``gemini-embedding-2``): overrides
      ``__call__`` with content-aware batching (respecting per-model
      limits on images, videos, audios, PDFs).  Each input is wrapped
      in a ``Content`` object so the API returns separate embeddings.

    Key API differences from other providers:

    - Dimensions are controlled via ``output_dimensionality`` in the
      ``config`` parameter (not a top-level ``dimensions`` field).
    - ``gemini-embedding-001`` supports ``task_type`` in config;
      ``gemini-embedding-2`` uses prompt prefixes instead.
    """

    #: Text-mode batch size.  Gemini docs don't specify an explicit
    #: limit; we use a conservative default.
    _TEXT_BATCH_SIZE: int = 100

    def __init__(
        self,
        credential: CredentialBase,
        model: str,
        dimensions: int | None,
        parameters: "GeminiEmbeddingModel.Parameters | None" = None,
        embedding_cache: EmbeddingCacheBase | None = None,
        context_size: int = 8192,
        max_retries: int = 3,
        retry_delay: float = 1.0,
    ) -> None:
        """Initialize the Gemini embedding model.

        Args:
            credential (`CredentialBase`):
                A :class:`~agentscope.credential.GeminiCredential`
                instance providing the API key.
            model (`str`):
                The embedding model name (e.g.
                ``"gemini-embedding-001"`` or
                ``"gemini-embedding-2"``).
            dimensions (`int | None`):
                The output embedding vector dimensions.  Required at
                the contract level — see :class:`EmbeddingModelBase`
                for the rationale.  ``None`` is accepted only for
                backward compatibility with legacy configs that
                persisted ``dimensions`` inside ``parameters``.
            parameters (`GeminiEmbeddingModel.Parameters | None`, \
            defaults to ``None``):
                Provider-specific non-dimensional parameters.  Currently
                empty for Gemini.
            embedding_cache (`EmbeddingCacheBase | None`, defaults to \
            ``None``):
                Optional embedding cache.
            context_size (`int`, defaults to ``8192``):
                Maximum input tokens.  2048 for ``gemini-embedding-001``,
                8192 for ``gemini-embedding-2``.
            max_retries (`int`, defaults to ``3``):
                Number of retries on transient failures.
            retry_delay (`float`, defaults to ``1.0``):
                Seconds between retry attempts.
        """
        from google import genai

        self._is_multimodal: bool = model.startswith(_MULTIMODAL_PREFIXES)

        super().__init__(
            credential=credential,
            model=model,
            dimensions=dimensions,
            parameters=parameters,
            context_size=context_size,
            batch_size=self._TEXT_BATCH_SIZE,
            max_retries=max_retries,
            retry_delay=retry_delay,
        )
        self.supports_multimodal = self._is_multimodal

        self.client: genai.Client = genai.Client(
            api_key=credential.api_key.get_secret_value(),
        )
        self.embedding_cache: EmbeddingCacheBase | None = embedding_cache

        if self._is_multimodal:
            self._limits = _MODEL_LIMITS.get(model, _DEFAULT_LIMITS)

    # ------------------------------------------------------------------
    # __call__ — override for multimodal content-aware batching
    # ------------------------------------------------------------------

    async def __call__(
        self,
        inputs: list[str | TextBlock | DataBlock],
        **kwargs: Any,
    ) -> EmbeddingResponse:
        """Embed inputs with batching and retry.

        For text models, delegates to the base class.  For multimodal
        models, performs content-aware batching that respects per-model
        limits on images, videos, audios, and PDFs.

        Args:
            inputs (`list[str | TextBlock | DataBlock]`):
                The input data to embed.  ``TextBlock`` items are
                unpacked to their ``.text`` field on entry, so the
                remainder of the pipeline only sees ``str`` and
                ``DataBlock``.
            **kwargs:
                Forwarded to the Gemini API config.

        Returns:
            `EmbeddingResponse`: Merged response for all inputs.
        """
        normalized: list[str | DataBlock] = [
            item.text if isinstance(item, TextBlock) else item
            for item in inputs
        ]

        if not self._is_multimodal:
            return await super().__call__(normalized, **kwargs)

        batches = self._split_multimodal_batches(normalized)

        if len(batches) > 1:
            logger.info(
                "Embedding %d multimodal inputs in %d batches "
                "for model %s.",
                len(normalized),
                len(batches),
                self.model,
            )

        results: list[EmbeddingResponse] = await asyncio.gather(
            *(self._call_with_retry(batch, **kwargs) for batch in batches),
        )

        return self._merge_responses(results)

    def _split_multimodal_batches(
        self,
        inputs: list[str | DataBlock],
    ) -> list[list[str | DataBlock]]:
        """Split inputs into batches respecting Gemini multimodal limits.

        Greedy: keep adding items until any constraint would be
        violated, then start a new batch.

        Args:
            inputs (`list[str | DataBlock]`):
                All inputs to split.

        Returns:
            `list[list[str | DataBlock]]`: List of batches.
        """
        limits = self._limits
        batches: list[list[str | DataBlock]] = []
        current: list[str | DataBlock] = []
        n_elem = 0
        n_img = 0
        n_vid = 0
        n_aud = 0
        n_pdf = 0

        for item in inputs:
            is_img = is_vid = is_aud = is_pdf = False
            if isinstance(item, DataBlock):
                mt = item.source.media_type
                is_img = mt.startswith("image/")
                is_vid = mt.startswith("video/")
                is_aud = mt.startswith("audio/")
                is_pdf = mt == "application/pdf"

            would_exceed = (
                n_elem + 1 > limits.max_elements
                or (is_img and n_img + 1 > limits.max_images)
                or (is_vid and n_vid + 1 > limits.max_videos)
                or (is_aud and n_aud + 1 > limits.max_audios)
                or (is_pdf and n_pdf + 1 > limits.max_pdfs)
            )

            if would_exceed and current:
                batches.append(current)
                current = []
                n_elem = n_img = n_vid = n_aud = n_pdf = 0

            current.append(item)
            n_elem += 1
            n_img += is_img
            n_vid += is_vid
            n_aud += is_aud
            n_pdf += is_pdf

        if current:
            batches.append(current)

        return batches

    # ------------------------------------------------------------------
    # _call_api — single batch
    # ------------------------------------------------------------------

    async def _call_api(
        self,
        inputs: list[str | DataBlock],
        **kwargs: Any,
    ) -> EmbeddingResponse:
        """Route to text or multimodal Gemini API for a single batch.

        Args:
            inputs (`list[str | DataBlock]`):
                A single batch of inputs.
            **kwargs:
                Extra keyword arguments merged into the Gemini
                ``EmbedContentConfig``.

        Returns:
            `EmbeddingResponse`: Embedding vectors and usage info.
        """
        if self._is_multimodal:
            return await self._call_multimodal(inputs, **kwargs)
        return await self._call_text(inputs, **kwargs)

    # ------------------------------------------------------------------
    # Text API (gemini-embedding-001)
    # ------------------------------------------------------------------

    async def _call_text(
        self,
        inputs: list[str | DataBlock],
        **kwargs: Any,
    ) -> EmbeddingResponse:
        """Call the Gemini text embedding API for a single batch.

        Passes the list of strings directly to ``embed_content``,
        which returns one embedding per string.

        Args:
            inputs (`list[str | DataBlock]`):
                Must all be ``str``; raises ``ValueError`` otherwise.
            **kwargs:
                Merged into ``EmbedContentConfig`` (e.g.
                ``task_type``).

        Returns:
            `EmbeddingResponse`: Embedding vectors and usage info.
        """
        from google.genai import types

        texts: list[str] = []
        for item in inputs:
            if not isinstance(item, str):
                raise ValueError(
                    f"Text embedding model {self.model!r} only accepts "
                    f"str inputs, got {type(item).__name__}.",
                )
            texts.append(item)

        config = types.EmbedContentConfig(
            output_dimensionality=self.dimensions,
            **kwargs,
        )

        cache_key = {
            "model": self.model,
            "contents": texts,
            "output_dimensionality": self.dimensions,
            **kwargs,
        }

        if self.embedding_cache:
            cached = await self.embedding_cache.retrieve(
                identifier=cache_key,
            )
            if cached:
                return EmbeddingResponse(
                    embeddings=cached,
                    usage=EmbeddingUsage(tokens=0, time=0),
                    source="cache",
                )

        start_time = datetime.now()
        response = self.client.models.embed_content(
            model=self.model,
            contents=texts,
            config=config,
        )
        time = (datetime.now() - start_time).total_seconds()

        embeddings = [item.values for item in response.embeddings]

        if self.embedding_cache:
            await self.embedding_cache.store(
                identifier=cache_key,
                embeddings=embeddings,
            )

        return EmbeddingResponse(
            embeddings=embeddings,
            usage=EmbeddingUsage(time=time),
        )

    # ------------------------------------------------------------------
    # Multimodal API (gemini-embedding-2)
    # ------------------------------------------------------------------

    async def _call_multimodal(
        self,
        inputs: list[str | DataBlock],
        **kwargs: Any,
    ) -> EmbeddingResponse:
        """Call the Gemini multimodal embedding API for a single batch.

        Each input is wrapped in a separate ``Content`` object so the
        API returns one embedding per input (not one aggregated
        embedding).

        Args:
            inputs (`list[str | DataBlock]`):
                ``str`` for text, ``DataBlock`` for images / video /
                audio / PDF.
            **kwargs:
                Merged into ``EmbedContentConfig``.

        Returns:
            `EmbeddingResponse`: Embedding vectors and usage info.
        """
        from google.genai import types

        contents: list[types.Content] = []
        for item in inputs:
            if isinstance(item, str):
                contents.append(
                    types.Content(
                        parts=[types.Part.from_text(text=item)],
                    ),
                )
            elif isinstance(item, DataBlock):
                contents.append(
                    types.Content(
                        parts=[self._data_block_to_part(item)],
                    ),
                )
            else:
                raise ValueError(
                    f"Invalid input: {item!r}. Expected str or DataBlock.",
                )

        config = types.EmbedContentConfig(
            output_dimensionality=self.dimensions,
            **kwargs,
        )

        start_time = datetime.now()
        response = self.client.models.embed_content(
            model=self.model,
            contents=contents,
            config=config,
        )
        time = (datetime.now() - start_time).total_seconds()

        embeddings = [item.values for item in response.embeddings]

        return EmbeddingResponse(
            embeddings=embeddings,
            usage=EmbeddingUsage(time=time),
        )

    # ------------------------------------------------------------------
    # Helpers
    # ------------------------------------------------------------------

    @staticmethod
    def _data_block_to_part(block: DataBlock) -> Any:
        """Convert a :class:`~agentscope.message.DataBlock` to a Gemini
        ``Part`` object.

        Args:
            block (`DataBlock`):
                A data block with ``Base64Source`` or ``URLSource``.

        Returns:
            A ``google.genai.types.Part`` instance.

        Raises:
            `ValueError`: If the source type is unsupported.
        """
        from google.genai import types
        from ...message import Base64Source, URLSource

        source = block.source

        if isinstance(source, Base64Source):
            import base64

            return types.Part.from_bytes(
                data=base64.b64decode(source.data),
                mime_type=source.media_type,
            )

        if isinstance(source, URLSource):
            # Gemini SDK doesn't have a direct from_url for
            # embed_content; download or use File API.
            # For now, raise — callers should use Base64Source.
            raise ValueError(
                "Gemini embedding API requires inline data "
                "(Base64Source). URLSource is not directly supported "
                f"for embedding. Got URL: {source.url}",
            )

        raise ValueError(
            f"Unsupported source type {type(source).__name__} "
            f"in DataBlock.",
        )