"""Derivations of standard content blocks from Anthropic content."""

import json
from collections.abc import Iterable
from typing import Any, cast

from langchain_core.messages import AIMessage, AIMessageChunk
from langchain_core.messages import content as types


def _populate_extras(
    standard_block: types.ContentBlock, block: dict[str, Any], known_fields: set[str]
) -> types.ContentBlock:
    """Mutate a block, populating extras."""
    if standard_block.get("type") == "non_standard":
        return standard_block

    for key, value in block.items():
        if key not in known_fields:
            if "extras" not in standard_block:
                # Below type-ignores are because mypy thinks a non-standard block can
                # get here, although we exclude them above.
                standard_block["extras"] = {}  # type: ignore[typeddict-unknown-key]
            standard_block["extras"][key] = value  # type: ignore[typeddict-item]

    return standard_block


def _convert_to_v1_from_anthropic_input(
    content: list[types.ContentBlock],
) -> list[types.ContentBlock]:
    """Convert Anthropic format blocks to v1 format.

    During the `content_blocks` parsing process, we wrap blocks not recognized as a v1
    block as a `'non_standard'` block with the original block stored in the `value`
    field. This function attempts to unpack those blocks and convert any blocks that
    might be Anthropic format to v1 ContentBlocks.

    If conversion fails, the block is left as a `'non_standard'` block.

    Args:
        content: List of content blocks to process.

    Returns:
        Updated list with Anthropic blocks converted to v1 format.
    """

    def _iter_blocks() -> Iterable[types.ContentBlock]:
        blocks: list[dict[str, Any]] = [
            cast("dict[str, Any]", block)
            if block.get("type") != "non_standard"
            else block["value"]  # type: ignore[typeddict-item]  # this is only non-standard blocks
            for block in content
        ]
        for block in blocks:
            block_type = block.get("type")

            if (
                block_type == "document"
                and "source" in block
                and "type" in block["source"]
            ):
                if block["source"]["type"] == "base64":
                    file_block: types.FileContentBlock = {
                        "type": "file",
                        "base64": block["source"]["data"],
                        "mime_type": block["source"]["media_type"],
                    }
                    _populate_extras(file_block, block, {"type", "source"})
                    yield file_block

                elif block["source"]["type"] == "url":
                    file_block = {
                        "type": "file",
                        "url": block["source"]["url"],
                    }
                    _populate_extras(file_block, block, {"type", "source"})
                    yield file_block

                elif block["source"]["type"] == "file":
                    file_block = {
                        "type": "file",
                        "id": block["source"]["file_id"],
                    }
                    _populate_extras(file_block, block, {"type", "source"})
                    yield file_block

                elif block["source"]["type"] == "text":
                    plain_text_block: types.PlainTextContentBlock = {
                        "type": "text-plain",
                        "text": block["source"]["data"],
                        "mime_type": block.get("media_type", "text/plain"),
                    }
                    _populate_extras(plain_text_block, block, {"type", "source"})
                    yield plain_text_block

                else:
                    yield {"type": "non_standard", "value": block}

            elif (
                block_type == "image"
                and "source" in block
                and "type" in block["source"]
            ):
                if block["source"]["type"] == "base64":
                    image_block: types.ImageContentBlock = {
                        "type": "image",
                        "base64": block["source"]["data"],
                        "mime_type": block["source"]["media_type"],
                    }
                    _populate_extras(image_block, block, {"type", "source"})
                    yield image_block

                elif block["source"]["type"] == "url":
                    image_block = {
                        "type": "image",
                        "url": block["source"]["url"],
                    }
                    _populate_extras(image_block, block, {"type", "source"})
                    yield image_block

                elif block["source"]["type"] == "file":
                    image_block = {
                        "type": "image",
                        "id": block["source"]["file_id"],
                    }
                    _populate_extras(image_block, block, {"type", "source"})
                    yield image_block

                else:
                    yield {"type": "non_standard", "value": block}

            elif block_type in types.KNOWN_BLOCK_TYPES:
                yield cast("types.ContentBlock", block)

            else:
                yield {"type": "non_standard", "value": block}

    return list(_iter_blocks())


def _convert_citation_to_v1(citation: dict[str, Any]) -> types.Annotation:
    citation_type = citation.get("type")

    if citation_type == "web_search_result_location":
        url_citation: types.Citation = {
            "type": "citation",
            "cited_text": citation["cited_text"],
            "url": citation["url"],
        }
        if title := citation.get("title"):
            url_citation["title"] = title
        known_fields = {"type", "cited_text", "url", "title", "index", "extras"}
        for key, value in citation.items():
            if key not in known_fields:
                if "extras" not in url_citation:
                    url_citation["extras"] = {}
                url_citation["extras"][key] = value

        return url_citation

    if citation_type in (
        "char_location",
        "content_block_location",
        "page_location",
        "search_result_location",
    ):
        document_citation: types.Citation = {
            "type": "citation",
            "cited_text": citation["cited_text"],
        }
        if "document_title" in citation:
            document_citation["title"] = citation["document_title"]
        elif title := citation.get("title"):
            document_citation["title"] = title
        else:
            pass
        known_fields = {
            "type",
            "cited_text",
            "document_title",
            "title",
            "index",
            "extras",
        }
        for key, value in citation.items():
            if key not in known_fields:
                if "extras" not in document_citation:
                    document_citation["extras"] = {}
                document_citation["extras"][key] = value

        return document_citation

    return {
        "type": "non_standard_annotation",
        "value": citation,
    }


def _convert_to_v1_from_anthropic(message: AIMessage) -> list[types.ContentBlock]:
    """Convert Anthropic message content to v1 format."""
    if isinstance(message.content, str):
        content: list[str | dict] = [{"type": "text", "text": message.content}]
    else:
        content = message.content

    def _iter_blocks() -> Iterable[types.ContentBlock]:
        for block in content:
            if not isinstance(block, dict):
                continue
            block_type = block.get("type")

            if block_type == "text":
                if citations := block.get("citations"):
                    text_block: types.TextContentBlock = {
                        "type": "text",
                        "text": block.get("text", ""),
                        "annotations": [_convert_citation_to_v1(a) for a in citations],
                    }
                else:
                    text_block = {"type": "text", "text": block["text"]}
                if "index" in block:
                    text_block["index"] = block["index"]
                yield text_block

            elif block_type == "thinking":
                reasoning_block: types.ReasoningContentBlock = {
                    "type": "reasoning",
                    "reasoning": block.get("thinking", ""),
                }
                if "index" in block:
                    reasoning_block["index"] = block["index"]
                known_fields = {"type", "thinking", "index", "extras"}
                for key in block:
                    if key not in known_fields:
                        if "extras" not in reasoning_block:
                            reasoning_block["extras"] = {}
                        reasoning_block["extras"][key] = block[key]
                yield reasoning_block

            elif block_type == "tool_use":
                if (
                    isinstance(message, AIMessageChunk)
                    and len(message.tool_call_chunks) == 1
                    and message.chunk_position != "last"
                ):
                    # Isolated chunk
                    tool_call_chunk: types.ToolCallChunk = (
                        message.tool_call_chunks[0].copy()  # type: ignore[assignment]
                    )
                    if "type" not in tool_call_chunk:
                        tool_call_chunk["type"] = "tool_call_chunk"
                    yield tool_call_chunk
                else:
                    tool_call_block: types.ToolCall | None = None
                    # Non-streaming or gathered chunk
                    if len(message.tool_calls) == 1:
                        tool_call_block = {
                            "type": "tool_call",
                            "name": message.tool_calls[0]["name"],
                            "args": message.tool_calls[0]["args"],
                            "id": message.tool_calls[0].get("id"),
                        }
                    elif call_id := block.get("id"):
                        for tc in message.tool_calls:
                            if tc.get("id") == call_id:
                                tool_call_block = {
                                    "type": "tool_call",
                                    "name": tc["name"],
                                    "args": tc["args"],
                                    "id": tc.get("id"),
                                }
                                break
                    else:
                        pass
                    if not tool_call_block:
                        tool_call_block = {
                            "type": "tool_call",
                            "name": block.get("name", ""),
                            "args": block.get("input", {}),
                            "id": block.get("id", ""),
                        }
                    if "index" in block:
                        tool_call_block["index"] = block["index"]
                    yield tool_call_block

            elif block_type == "input_json_delta" and isinstance(
                message, AIMessageChunk
            ):
                if len(message.tool_call_chunks) == 1:
                    tool_call_chunk = (
                        message.tool_call_chunks[0].copy()  # type: ignore[assignment]
                    )
                    if "type" not in tool_call_chunk:
                        tool_call_chunk["type"] = "tool_call_chunk"
                    yield tool_call_chunk

                else:
                    server_tool_call_chunk: types.ServerToolCallChunk = {
                        "type": "server_tool_call_chunk",
                        "args": block.get("partial_json", ""),
                    }
                    if "index" in block:
                        server_tool_call_chunk["index"] = block["index"]
                    yield server_tool_call_chunk

            elif block_type == "server_tool_use":
                if block.get("name") == "code_execution":
                    server_tool_use_name = "code_interpreter"
                else:
                    server_tool_use_name = block.get("name", "")
                if (
                    isinstance(message, AIMessageChunk)
                    and block.get("input") == {}
                    and "partial_json" not in block
                    and message.chunk_position != "last"
                ):
                    # First chunk in a stream
                    server_tool_call_chunk = {
                        "type": "server_tool_call_chunk",
                        "name": server_tool_use_name,
                        "args": "",
                        "id": block.get("id", ""),
                    }
                    if "index" in block:
                        server_tool_call_chunk["index"] = block["index"]
                    known_fields = {"type", "name", "input", "id", "index"}
                    _populate_extras(server_tool_call_chunk, block, known_fields)
                    yield server_tool_call_chunk
                else:
                    server_tool_call: types.ServerToolCall = {
                        "type": "server_tool_call",
                        "name": server_tool_use_name,
                        "args": block.get("input", {}),
                        "id": block.get("id", ""),
                    }

                    if block.get("input") == {} and "partial_json" in block:
                        try:
                            input_ = json.loads(block["partial_json"])
                            if isinstance(input_, dict):
                                server_tool_call["args"] = input_
                        except json.JSONDecodeError:
                            pass

                    if "index" in block:
                        server_tool_call["index"] = block["index"]
                    known_fields = {
                        "type",
                        "name",
                        "input",
                        "partial_json",
                        "id",
                        "index",
                    }
                    _populate_extras(server_tool_call, block, known_fields)

                    yield server_tool_call

            elif block_type == "mcp_tool_use":
                if (
                    isinstance(message, AIMessageChunk)
                    and block.get("input") == {}
                    and "partial_json" not in block
                    and message.chunk_position != "last"
                ):
                    # First chunk in a stream
                    server_tool_call_chunk = {
                        "type": "server_tool_call_chunk",
                        "name": "remote_mcp",
                        "args": "",
                        "id": block.get("id", ""),
                    }
                    if "name" in block:
                        server_tool_call_chunk["extras"] = {"tool_name": block["name"]}
                    known_fields = {"type", "name", "input", "id", "index"}
                    _populate_extras(server_tool_call_chunk, block, known_fields)
                    if "index" in block:
                        server_tool_call_chunk["index"] = block["index"]
                    yield server_tool_call_chunk
                else:
                    server_tool_call = {
                        "type": "server_tool_call",
                        "name": "remote_mcp",
                        "args": block.get("input", {}),
                        "id": block.get("id", ""),
                    }

                    if block.get("input") == {} and "partial_json" in block:
                        try:
                            input_ = json.loads(block["partial_json"])
                            if isinstance(input_, dict):
                                server_tool_call["args"] = input_
                        except json.JSONDecodeError:
                            pass

                    if "name" in block:
                        server_tool_call["extras"] = {"tool_name": block["name"]}
                    known_fields = {
                        "type",
                        "name",
                        "input",
                        "partial_json",
                        "id",
                        "index",
                    }
                    _populate_extras(server_tool_call, block, known_fields)
                    if "index" in block:
                        server_tool_call["index"] = block["index"]

                    yield server_tool_call

            elif block_type and block_type.endswith("_tool_result"):
                server_tool_result: types.ServerToolResult = {
                    "type": "server_tool_result",
                    "tool_call_id": block.get("tool_use_id", ""),
                    "status": "success",
                    "extras": {"block_type": block_type},
                }
                if output := block.get("content", []):
                    server_tool_result["output"] = output
                    if isinstance(output, dict) and output.get(
                        "error_code"  # web_search, code_interpreter
                    ):
                        server_tool_result["status"] = "error"
                if block.get("is_error"):  # mcp_tool_result
                    server_tool_result["status"] = "error"
                if "index" in block:
                    server_tool_result["index"] = block["index"]

                known_fields = {"type", "tool_use_id", "content", "is_error", "index"}
                _populate_extras(server_tool_result, block, known_fields)

                yield server_tool_result

            else:
                new_block: types.NonStandardContentBlock = {
                    "type": "non_standard",
                    "value": block,
                }
                if "index" in new_block["value"]:
                    new_block["index"] = new_block["value"].pop("index")
                yield new_block

    return list(_iter_blocks())


def translate_content(message: AIMessage) -> list[types.ContentBlock]:
    """Derive standard content blocks from a message with Anthropic content."""
    return _convert_to_v1_from_anthropic(message)


def translate_content_chunk(message: AIMessageChunk) -> list[types.ContentBlock]:
    """Derive standard content blocks from a message chunk with Anthropic content."""
    return _convert_to_v1_from_anthropic(message)


def _register_anthropic_translator() -> None:
    """Register the Anthropic translator with the central registry.

    Run automatically when the module is imported.
    """
    from langchain_core.messages.block_translators import (  # noqa: PLC0415
        register_translator,
    )

    register_translator("anthropic", translate_content, translate_content_chunk)


_register_anthropic_translator()
