"""
Code agent backend - handles code execution with E2B
"""
import json
import logging
import os
import re
from typing import List, Dict, Optional
from e2b_code_interpreter import Sandbox

from .tools import execute_code, upload_files, download_files
from .image import resize_image_for_vlm

logger = logging.getLogger(__name__)

TOOLS = [execute_code, upload_files, download_files]

MAX_TURNS = 40


def parse_execution_result(execution, max_output_length=4000):
    """Parse execution result for LLM feedback"""
    output = []

    def truncate_if_needed(text):
        if len(text) > max_output_length:
            half = max_output_length // 2
            return text[:half] + f"\n\n[... truncated {len(text) - max_output_length} of {len(text)} chars ...]\n\n" + text[-half:]
        return text

    # Check for images/plots
    has_images = any(result.png or result.jpeg or result.svg for result in execution.results)

    if has_images:
        output.append("[Plot/Image generated]")

    if execution.results:
        # Filter out Figure text representations
        text_results = [result.text for result in execution.results if result.text and not result.text.startswith('<Figure')]
        if text_results:
            output.append(truncate_if_needed("\n".join(text_results)))

    if execution.logs.stdout:
        output.append(truncate_if_needed("\n".join(execution.logs.stdout)))
    if execution.logs.stderr:
        output.append(truncate_if_needed("\n".join(execution.logs.stderr)))
    if execution.error is not None:
        output.append(truncate_if_needed(execution.error.traceback))

    return "\n".join(filter(None, output))


def format_code_cell(code: str, execution_result: str = None, error: bool = False, images: list = None):
    """Format a code cell for display in the UI"""
    return {
        "type": "code",
        "code": code,
        "output": execution_result,
        "error": error,
        "images": images or []
    }


def format_thinking_cell(content: str):
    """Format assistant thinking for display"""
    return {
        "type": "thinking",
        "content": content
    }


def upload_files_to_sandbox(sbx: Sandbox, paths: List[str], files_root: str) -> str:
    """
    Upload multiple files to the sandbox.

    Args:
        sbx: E2B sandbox instance
        paths: List of relative file paths
        files_root: Root directory to resolve relative paths

    Returns:
        String describing what was uploaded or errors encountered
    """
    results = []

    for rel_path in paths:
        # Normalize the path (remove ./ prefix if present)
        rel_path = rel_path.lstrip('./')
        local_path = os.path.join(files_root, rel_path)

        # Security check: ensure path doesn't escape files_root
        real_local = os.path.realpath(local_path)
        real_root = os.path.realpath(files_root)
        if not real_local.startswith(real_root):
            results.append(f"Error: {rel_path} - path outside workspace")
            continue

        if not os.path.exists(local_path):
            results.append(f"Error: {rel_path} - file not found")
            continue

        if not os.path.isfile(local_path):
            results.append(f"Error: {rel_path} - not a file")
            continue

        try:
            # Get just the filename for the sandbox path
            filename = os.path.basename(rel_path)
            sandbox_path = f"/home/user/{filename}"

            with open(local_path, "rb") as f:
                sbx.files.write(sandbox_path, f)

            results.append(f"Uploaded: {rel_path} -> {sandbox_path}")
        except Exception as e:
            results.append(f"Error uploading {rel_path}: {str(e)}")

    return "\n".join(results)


def download_files_from_sandbox(sbx: Sandbox, files: List[Dict], files_root: str) -> str:
    """
    Download multiple files from the sandbox to the local workspace.

    Args:
        sbx: E2B sandbox instance
        files: List of dicts with 'sandbox_path' and 'local_path' keys
        files_root: Root directory to resolve relative paths

    Returns:
        String describing what was downloaded or errors encountered
    """
    results = []

    for file_spec in files:
        sandbox_path = file_spec.get('sandbox_path', '')
        local_rel_path = file_spec.get('local_path', '')

        if not sandbox_path or not local_rel_path:
            results.append(f"Error: Missing sandbox_path or local_path")
            continue

        # Normalize the local path (remove ./ prefix if present)
        local_rel_path = local_rel_path.lstrip('./')
        local_path = os.path.join(files_root, local_rel_path)

        # Security check: ensure path doesn't escape files_root
        real_local = os.path.realpath(os.path.dirname(local_path))
        real_root = os.path.realpath(files_root)
        # Need to handle case where parent dir doesn't exist yet
        test_path = local_path
        while not os.path.exists(os.path.dirname(test_path)):
            test_path = os.path.dirname(test_path)
        real_local = os.path.realpath(test_path)
        if not real_local.startswith(real_root):
            results.append(f"Error: {local_rel_path} - path outside workspace")
            continue

        try:
            # Read file content from sandbox (use bytes for binary files)
            content = sbx.files.read(sandbox_path, format='bytes')

            # Create parent directories if needed
            os.makedirs(os.path.dirname(local_path), exist_ok=True)

            # Write to local file
            with open(local_path, 'wb') as f:
                f.write(content)

            results.append(f"Downloaded: {sandbox_path} -> {local_rel_path}")
        except Exception as e:
            results.append(f"Error downloading {sandbox_path}: {str(e)}")

    return "\n".join(results)


def stream_code_execution(client, model: str, messages: List[Dict], sbx: Sandbox, files_root: str = None, extra_params: Optional[Dict] = None, abort_event=None, multimodal: bool = False, tab_id: str = "0", figure_store: Optional[Dict[str, dict]] = None):
    """
    Stream code execution results

    Yields:
        dict: Updates with type 'thinking', 'code', or 'done'

    Args:
        client: OpenAI-compatible client
        model: Model name to use
        messages: Conversation messages
        sbx: E2B sandbox instance
        files_root: Root directory for file uploads (optional)
        extra_params: Extra parameters for API calls (optional)
    """
    from .agents import call_llm

    turns = 0
    done = False
    figure_counter = 0  # Track figure numbers
    figure_prefix = f"figure_T{tab_id}_"
    # Use shared global store if provided, otherwise create local one
    if figure_store is None:
        figure_store = {}
    figure_data = figure_store  # Alias for clarity in this function
    has_result = False
    debug_call_number = 0

    while not done and turns < MAX_TURNS:
        # Check abort before each turn
        if abort_event and abort_event.is_set():
            yield {"type": "aborted"}
            return

        turns += 1

        # LLM call with retries and debug events
        response = None
        for event in call_llm(client, model, messages, tools=TOOLS, extra_params=extra_params, abort_event=abort_event, call_number=debug_call_number):
            if "_response" in event:
                response = event["_response"]
                debug_call_number = event["_call_number"]
            else:
                yield event
                if event.get("type") in ("error", "aborted"):
                    return

        if response is None:
            return

        # Get response
        assistant_message = response.choices[0].message
        content = assistant_message.content or ""
        tool_calls = assistant_message.tool_calls or []

        # Check for result tags
        result_match = re.search(r'<result>(.*?)</result>', content, re.DOTALL | re.IGNORECASE)
        result_content = None
        thinking_content = content

        if result_match:
            logger.debug(f"Result found: {content[:200]}...")
            result_content = result_match.group(1).strip()
            # Remove result tags from thinking display
            thinking_content = re.sub(r'<result>.*?</result>', '', content, flags=re.DOTALL | re.IGNORECASE).strip()

        # Send thinking if there's content (excluding result tags)
        if thinking_content.strip():
            yield format_thinking_cell(thinking_content)

        # Send result as a special highlighted message in the CODE notebook
        if result_content:
            yield {"type": "result_preview", "content": result_content, "figures": figure_data}

        # Handle tool calls
        if tool_calls:
            for tool_call in tool_calls:
                # Check abort between tool calls
                if abort_event and abort_event.is_set():
                    yield {"type": "aborted"}
                    return

                if tool_call.function.name == "execute_code":
                    # Parse arguments
                    try:
                        args = json.loads(tool_call.function.arguments)
                        code = args["code"]
                    except json.JSONDecodeError as e:
                        error_msg = f"JSON parse error: {e}. Raw arguments: {tool_call.function.arguments[:500]}"
                        logger.error(error_msg)
                        # Treat as tool error so LLM can recover
                        output = f"Error parsing code arguments: {e}"
                        messages.append({
                            "role": "assistant",
                            "content": content,
                            "tool_calls": [{
                                "id": tool_call.id,
                                "type": "function",
                                "function": {
                                    "name": tool_call.function.name,
                                    "arguments": tool_call.function.arguments,
                                }
                            }]
                        })
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": output
                        })
                        yield {"type": "error", "content": f"Failed to parse code arguments: {e}"}
                        continue
                    except KeyError as e:
                        error_msg = f"Missing required key {e} in arguments: {tool_call.function.arguments[:500]}"
                        logger.error(error_msg)
                        output = f"Error: Missing required 'code' parameter"
                        messages.append({
                            "role": "assistant",
                            "content": content,
                            "tool_calls": [{
                                "id": tool_call.id,
                                "type": "function",
                                "function": {
                                    "name": tool_call.function.name,
                                    "arguments": tool_call.function.arguments,
                                }
                            }]
                        })
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": output
                        })
                        yield {"type": "error", "content": output}
                        continue

                    # Send code cell (before execution)
                    yield {"type": "code_start", "code": code}

                    # Execute code
                    try:
                        execution = sbx.run_code(code)
                        output = parse_execution_result(execution)
                        has_error = execution.error is not None

                        # Extract images and assign figure names
                        images = []
                        figure_names = []

                        for result in execution.results:
                            if not (result.png or result.jpeg or result.svg):
                                continue
                            figure_counter += 1
                            figure_name = f"{figure_prefix}{figure_counter}"
                            figure_names.append(figure_name)

                            if result.png:
                                images.append({"type": "png", "data": result.png, "name": figure_name})
                                figure_data[figure_name] = {"type": "png", "data": result.png}
                            elif result.jpeg:
                                images.append({"type": "jpeg", "data": result.jpeg, "name": figure_name})
                                figure_data[figure_name] = {"type": "jpeg", "data": result.jpeg}
                            elif result.svg:
                                images.append({"type": "svg", "data": result.svg, "name": figure_name})
                                figure_data[figure_name] = {"type": "svg", "data": result.svg}

                        # Add figure info to output for LLM
                        if figure_names:
                            figure_info = f"\n[Generated figures: {', '.join(figure_names)}]"
                            output = (output + figure_info) if output else figure_info.strip()

                        # Send execution result
                        yield format_code_cell(code, output, has_error, images)

                    except Exception as e:
                        error_str = str(e)
                        # Check if this is a sandbox timeout error - if so, re-raise to trigger cleanup
                        if "502" in error_str or "sandbox was not found" in error_str.lower() or "timeout" in error_str.lower():
                            raise  # Re-raise to be caught by main.py handler

                        yield format_code_cell(code, f"Execution error: {str(e)}", True)
                        output = f"Execution failed: {str(e)}"
                        has_error = True

                    # Add to message history
                    messages.append({
                        "role": "assistant",
                        "content": content,
                        "tool_calls": [{
                            "id": tool_call.id,
                            "type": "function",
                            "function": {
                                "name": tool_call.function.name,
                                "arguments": tool_call.function.arguments,
                            }
                        }]
                    })

                    # Build tool response — include figures if multimodal
                    if multimodal and images:
                        tool_content = [{"type": "text", "text": output}]
                        for img in images:
                            if img["type"] in ("png", "jpeg"):
                                vlm_img = resize_image_for_vlm(img["data"])
                                tool_content.append({
                                    "type": "image_url",
                                    "image_url": {"url": f"data:image/jpeg;base64,{vlm_img}"}
                                })
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": tool_content
                        })
                    else:
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": output
                        })

                elif tool_call.function.name == "upload_files":
                    # Parse arguments
                    try:
                        args = json.loads(tool_call.function.arguments)
                        paths = args["paths"]
                    except (json.JSONDecodeError, KeyError) as e:
                        error_msg = f"Failed to parse upload_files arguments: {e}. Raw: {tool_call.function.arguments[:500]}"
                        logger.error(error_msg)
                        output = f"Error parsing upload_files arguments: {e}"
                        messages.append({
                            "role": "assistant",
                            "content": content,
                            "tool_calls": [{
                                "id": tool_call.id,
                                "type": "function",
                                "function": {
                                    "name": tool_call.function.name,
                                    "arguments": tool_call.function.arguments,
                                }
                            }]
                        })
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": output
                        })
                        yield {"type": "error", "content": output}
                        continue

                    # Check if files_root is available
                    if not files_root:
                        output = "Error: File upload not available - no workspace configured"
                    else:
                        # Upload files
                        output = upload_files_to_sandbox(sbx, paths, files_root)

                    # Send upload notification to UI
                    yield {"type": "upload", "paths": paths, "output": output}

                    # Add to message history
                    messages.append({
                        "role": "assistant",
                        "content": content,
                        "tool_calls": [{
                            "id": tool_call.id,
                            "type": "function",
                            "function": {
                                "name": tool_call.function.name,
                                "arguments": tool_call.function.arguments,
                            }
                        }]
                    })

                    messages.append({
                        "role": "tool",
                        "tool_call_id": tool_call.id,
                        "content": output
                    })

                elif tool_call.function.name == "download_files":
                    # Parse arguments
                    try:
                        args = json.loads(tool_call.function.arguments)
                        files = args["files"]
                    except (json.JSONDecodeError, KeyError) as e:
                        error_msg = f"Failed to parse download_files arguments: {e}. Raw: {tool_call.function.arguments[:500]}"
                        logger.error(error_msg)
                        output = f"Error parsing download_files arguments: {e}"
                        messages.append({
                            "role": "assistant",
                            "content": content,
                            "tool_calls": [{
                                "id": tool_call.id,
                                "type": "function",
                                "function": {
                                    "name": tool_call.function.name,
                                    "arguments": tool_call.function.arguments,
                                }
                            }]
                        })
                        messages.append({
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": output
                        })
                        yield {"type": "error", "content": output}
                        continue

                    # Check if files_root is available
                    if not files_root:
                        output = "Error: File download not available - no workspace configured"
                    else:
                        # Download files
                        output = download_files_from_sandbox(sbx, files, files_root)

                    # Extract paths for UI display
                    paths = [f"{f.get('sandbox_path', '')} -> {f.get('local_path', '')}" for f in files]

                    # Send download notification to UI
                    yield {"type": "download", "paths": paths, "output": output}

                    # Add to message history
                    messages.append({
                        "role": "assistant",
                        "content": content,
                        "tool_calls": [{
                            "id": tool_call.id,
                            "type": "function",
                            "function": {
                                "name": tool_call.function.name,
                                "arguments": tool_call.function.arguments,
                            }
                        }]
                    })

                    messages.append({
                        "role": "tool",
                        "tool_call_id": tool_call.id,
                        "content": output
                    })
        else:
            # No tool calls - we're done
            messages.append({"role": "assistant", "content": content})
            done = True

        # If we found a result tag, send it with figure data
        if result_content:
            has_result = True
            yield {"type": "result", "content": result_content, "figures": figure_data}

        # Yield generating state between turns
        if not done:
            yield {"type": "generating"}

    # If agent finished without a <result>, nudge it for one
    if not has_result:
        from .agents import nudge_for_result
        yield from nudge_for_result(client, model, messages, extra_params=extra_params, extra_result_data={"figures": figure_data}, call_number=debug_call_number)

    # Send done signal
    yield {"type": "done"}