# -*- coding: utf-8 -*-
# pylint: disable=too-many-branches
"""Google gemini API formatter in agentscope."""
import base64
import os
from typing import Any
from urllib.parse import urlparse

from ._truncated_formatter_base import TruncatedFormatterBase
from .._utils._common import _get_bytes_from_web_url
from ..message import (
    Msg,
    TextBlock,
    ImageBlock,
    AudioBlock,
    ToolUseBlock,
    ToolResultBlock,
    VideoBlock,
    URLSource,
)
from .._logging import logger
from ..token import TokenCounterBase


def _format_gemini_media_block(
    media_block: ImageBlock | AudioBlock | VideoBlock,
) -> dict[str, Any]:
    """Format an image/audio/video block for Gemini API.

    Args:
        media_block (`ImageBlock | AudioBlock | VideoBlock`):
            The media block to format.

    Returns:
        `dict[str, Any]`:
            A dictionary with "inline_data" key in Gemini format.

    Raises:
        `ValueError`:
            If the source type is not supported.
    """
    source = media_block["source"]
    if source["type"] == "base64":
        return {
            "inline_data": {
                "data": source["data"],
                "mime_type": source["media_type"],
            },
        }
    elif source["type"] == "url":
        return {
            "inline_data": _to_gemini_inline_data(source["url"]),
        }
    else:
        raise ValueError(
            f"Unsupported source type: {source['type']}",
        )


def _to_gemini_inline_data(url: str) -> dict:
    """Convert url into the Gemini API required format."""
    parsed_url = urlparse(url)
    extension = url.split(".")[-1].lower()

    # Pre-calculate media type from extension (image/audio/video).
    typ = None
    for k, v in GeminiChatFormatter.supported_extensions.items():
        if extension in v:
            typ = k
            break

    if not os.path.exists(url) and parsed_url.scheme != "":
        # Web url
        if typ is None:
            raise TypeError(
                f"Unsupported file extension: {extension}, expected "
                f"{GeminiChatFormatter.supported_extensions}",
            )

        data = _get_bytes_from_web_url(url)
        return {
            "data": data,
            "mime_type": f"{typ}/{extension}",
        }

    elif os.path.exists(url):
        # Local file
        if typ is None:
            raise TypeError(
                f"Unsupported file extension: {extension}, expected "
                f"{GeminiChatFormatter.supported_extensions}",
            )

        with open(url, "rb") as f:
            data = base64.b64encode(f.read()).decode("utf-8")

        return {
            "data": data,
            "mime_type": f"{typ}/{extension}",
        }

    raise ValueError(
        f"The URL `{url}` is not a valid image URL or local file.",
    )


class GeminiChatFormatter(TruncatedFormatterBase):
    """The Gemini formatter class for chatbot scenario, where only a user
    and an agent are involved. We use the `role` field to identify different
    entities in the conversation.
    """

    support_tools_api: bool = True
    """Whether support tools API"""

    support_multiagent: bool = False
    """Whether support multi-agent conversations"""

    support_vision: bool = True
    """Whether support vision data"""

    supported_blocks: list[type] = [
        TextBlock,
        # Multimodal
        ImageBlock,
        VideoBlock,
        AudioBlock,
        # Tool use
        ToolUseBlock,
        ToolResultBlock,
    ]
    """The list of supported message blocks"""

    supported_extensions: dict[str, list[str]] = {
        "image": ["png", "jpeg", "webp", "heic", "heif"],
        "video": [
            "mp4",
            "mpeg",
            "mov",
            "avi",
            "x-flv",
            "mpg",
            "webm",
            "wmv",
            "3gpp",
        ],
        "audio": ["mp3", "wav", "aiff", "aac", "ogg", "flac"],
    }

    def __init__(
        self,
        promote_tool_result_images: bool = False,
        token_counter: TokenCounterBase | None = None,
        max_tokens: int | None = None,
    ) -> None:
        """Initialize the Gemini chat formatter.

        Args:
            promote_tool_result_images (`bool`, defaults to `False`):
                Whether to promote images from tool results to user messages.
                Most LLM APIs don't support images in tool result blocks, but
                do support them in user message blocks. When `True`, images are
                extracted and appended as a separate user message with
                explanatory text indicating their source.
            token_counter (`TokenCounterBase | None`, optional):
                A token counter instance used to count tokens in the messages.
                If not provided, the formatter will format the messages
                without considering token limits.
            max_tokens (`int | None`, optional):
                The maximum number of tokens allowed in the formatted
                messages. If not provided, the formatter will not truncate
                the messages.
        """
        super().__init__(token_counter, max_tokens)
        self.promote_tool_result_images = promote_tool_result_images

    async def _format(
        self,
        msgs: list[Msg],
    ) -> list[dict]:
        """Format message objects into Gemini API required format."""
        self.assert_list_of_msgs(msgs)

        messages: list = []
        i = 0
        while i < len(msgs):
            msg = msgs[i]
            parts = []

            for block in msg.get_content_blocks():
                typ = block.get("type")
                if typ == "text":
                    parts.append(
                        {
                            "text": block.get("text"),
                        },
                    )

                elif typ == "tool_use":
                    parts.append(
                        {
                            "function_call": {
                                "id": None,
                                "name": block["name"],
                                "args": block["input"],
                            },
                            "thought_signature": block.get("id", None),
                        },
                    )

                elif typ == "tool_result":
                    (
                        textual_output,
                        multimodal_data,
                    ) = self.convert_tool_result_to_string(block["output"])

                    # First add the tool result message in DashScope API format
                    messages.append(
                        {
                            "role": "user",
                            "parts": [
                                {
                                    "function_response": {
                                        "id": block["id"],
                                        "name": block["name"],
                                        "response": {
                                            "output": textual_output,
                                        },
                                    },
                                },
                            ],
                        },
                    )

                    promoted_blocks: list = []
                    for url, multimodal_block in multimodal_data:
                        if (
                            multimodal_block["type"] == "image"
                            and self.promote_tool_result_images
                        ):
                            promoted_blocks.extend(
                                [
                                    TextBlock(
                                        type="text",
                                        text=f"\n- The image from '{url}': ",
                                    ),
                                    ImageBlock(
                                        type="image",
                                        source=URLSource(
                                            type="url",
                                            url=url,
                                        ),
                                    ),
                                ],
                            )

                    if promoted_blocks:
                        # Insert promoted blocks as new user message(s)
                        promoted_blocks = [
                            TextBlock(
                                type="text",
                                text="<system-info>The following are "
                                "the image contents from the tool "
                                f"result of '{block['name']}':",
                            ),
                            *promoted_blocks,
                            TextBlock(
                                type="text",
                                text="</system-info>",
                            ),
                        ]

                        msgs.insert(
                            i + 1,
                            Msg(
                                name="user",
                                content=promoted_blocks,
                                role="user",
                            ),
                        )

                elif typ in ["image", "audio", "video"]:
                    parts.append(
                        _format_gemini_media_block(
                            block,  # type: ignore[arg-type]
                        ),
                    )

                else:
                    logger.warning(
                        "Unsupported block type: %s in the message, skipped. ",
                        typ,
                    )

            role = "model" if msg.role == "assistant" else "user"

            if parts:
                messages.append(
                    {
                        "role": role,
                        "parts": parts,
                    },
                )

            # Move to next message (including inserted messages, which will
            # be processed in subsequent iterations)
            i += 1

        return messages


class GeminiMultiAgentFormatter(TruncatedFormatterBase):
    """The multi-agent formatter for Google Gemini API, where more than a
    user and an agent are involved.

    .. note:: This formatter will combine previous messages (except tool
     calls/results) into a history section in the first system message with
     the conversation history prompt.

    .. note:: For tool calls/results, they will be presented as separate
     messages as required by the Gemini API. Therefore, the tool calls/
     results messages are expected to be placed at the end of the input
     messages.

    .. tip:: Telling the assistant's name in the system prompt is very
     important in multi-agent conversations. So that LLM can know who it
     is playing as.

    """

    support_tools_api: bool = True
    """Whether support tools API"""

    support_multiagent: bool = True
    """Whether support multi-agent conversations"""

    support_vision: bool = True
    """Whether support vision data"""

    supported_blocks: list[type] = [
        TextBlock,
        # Multimodal
        ImageBlock,
        VideoBlock,
        AudioBlock,
        # Tool use
        ToolUseBlock,
        ToolResultBlock,
    ]
    """The list of supported message blocks"""

    def __init__(
        self,
        conversation_history_prompt: str = (
            "# Conversation History\n"
            "The content between <history></history> tags contains "
            "your conversation history\n"
        ),
        promote_tool_result_images: bool = False,
        token_counter: TokenCounterBase | None = None,
        max_tokens: int | None = None,
    ) -> None:
        """Initialize the Gemini multi-agent formatter.

        Args:
            conversation_history_prompt (`str`):
                The prompt to be used for the conversation history section.
            promote_tool_result_images (`bool`, defaults to `False`):
                Whether to promote images from tool results to user messages.
                Most LLM APIs don't support images in tool result blocks, but
                do support them in user message blocks. When `True`, images are
                extracted and appended as a separate user message with
                explanatory text indicating their source.
            token_counter (`TokenCounterBase | None`, optional):
                The token counter used for truncation.
            max_tokens (`int | None`, optional):
                The maximum number of tokens allowed in the formatted
                messages. If `None`, no truncation will be applied.
        """
        super().__init__(token_counter=token_counter, max_tokens=max_tokens)
        self.conversation_history_prompt = conversation_history_prompt
        self.promote_tool_result_images = promote_tool_result_images

    async def _format_system_message(
        self,
        msg: Msg,
    ) -> dict[str, Any]:
        """Format system message for the Gemini API."""
        return {
            "role": "user",
            "parts": [
                {
                    "text": msg.get_text_content(),
                },
            ],
        }

    async def _format_tool_sequence(
        self,
        msgs: list[Msg],
    ) -> list[dict[str, Any]]:
        """Given a sequence of tool call/result messages, format them into
        the required format for the Gemini API.

        Args:
            msgs (`list[Msg]`):
                The list of messages containing tool calls/results to format.

        Returns:
            `list[dict[str, Any]]`:
                A list of dictionaries formatted for the Gemini API.
        """
        return await GeminiChatFormatter(
            promote_tool_result_images=self.promote_tool_result_images,
        ).format(msgs)

    async def _format_agent_message(
        self,
        msgs: list[Msg],
        is_first: bool = True,
    ) -> list[dict[str, Any]]:
        """Given a sequence of messages without tool calls/results, format
        them into the required format for the Gemini API.

        Args:
            msgs (`list[Msg]`):
                A list of Msg objects to be formatted.
            is_first (`bool`, defaults to `True`):
                Whether this is the first agent message in the conversation.
                If `True`, the conversation history prompt will be included.

        Returns:
            `list[dict[str, Any]]`:
                A list of dictionaries formatted for the Gemini API.
        """

        if is_first:
            conversation_history_prompt = self.conversation_history_prompt
        else:
            conversation_history_prompt = ""

        # Format into Gemini API required format
        formatted_msgs: list = []

        # Collect the multimodal files
        conversation_parts: list = []
        accumulated_text = []
        for msg in msgs:
            for block in msg.get_content_blocks():
                if block["type"] == "text":
                    accumulated_text.append(f"{msg.name}: {block['text']}")

                elif block["type"] in ["image", "video", "audio"]:
                    # handle the accumulated text as a single part if exists
                    if accumulated_text:
                        conversation_parts.append(
                            {
                                "text": "\n".join(accumulated_text),
                            },
                        )
                        accumulated_text.clear()

                    # handle the multimodal data
                    conversation_parts.append(
                        _format_gemini_media_block(
                            block,  # type: ignore[arg-type]
                        ),
                    )

        if accumulated_text:
            conversation_parts.append(
                {
                    "text": "\n".join(accumulated_text),
                },
            )

        # Add prompt and <history></history> tags around conversation history
        if conversation_parts:
            if conversation_parts[0].get("text"):
                conversation_parts[0]["text"] = (
                    conversation_history_prompt
                    + "<history>"
                    + conversation_parts[0]["text"]
                )

            else:
                conversation_parts.insert(
                    0,
                    {"text": conversation_history_prompt + "<history>"},
                )

            if conversation_parts[-1].get("text"):
                conversation_parts[-1]["text"] += "\n</history>"

            else:
                conversation_parts.append(
                    {"text": "</history>"},
                )

            formatted_msgs.append(
                {
                    "role": "user",
                    "parts": conversation_parts,
                },
            )

        return formatted_msgs
