import base64
import hashlib
import os
import subprocess
from datetime import datetime

import structlog
from fastapi import BackgroundTasks

from skyvern.exceptions import ScriptNotFound
from skyvern.forge import app
from skyvern.schemas.scripts import FileNode, ScriptFileCreate

LOG = structlog.get_logger(__name__)


async def build_file_tree(
    files: list[ScriptFileCreate],
    organization_id: str,
    script_id: str,
    script_version: int,
    script_revision_id: str,
) -> dict[str, FileNode]:
    """Build a hierarchical file tree from a list of files and upload the files to s3 with the same tree structure."""
    file_tree: dict[str, FileNode] = {}

    for file in files:
        # Decode content to calculate size and hash
        content_bytes = base64.b64decode(file.content)
        content_hash = hashlib.sha256(content_bytes).hexdigest()
        file_size = len(content_bytes)

        # Create artifact and upload to S3
        try:
            artifact_id = await app.ARTIFACT_MANAGER.create_script_file_artifact(
                organization_id=organization_id,
                script_id=script_id,
                script_version=script_version,
                file_path=file.path,
                data=content_bytes,
            )
            LOG.debug(
                "Created script file artifact",
                artifact_id=artifact_id,
                file_path=file.path,
                script_id=script_id,
                script_version=script_version,
            )
            # create a script file record
            await app.DATABASE.create_script_file(
                script_revision_id=script_revision_id,
                script_id=script_id,
                organization_id=organization_id,
                file_path=file.path,
                file_name=file.path.split("/")[-1],
                file_type="file",
                content_hash=f"sha256:{content_hash}",
                file_size=file_size,
                mime_type=file.mime_type,
                artifact_id=artifact_id,
            )
        except Exception:
            LOG.exception(
                "Failed to create script file artifact",
                file_path=file.path,
                script_id=script_id,
                script_version=script_version,
                script_revision_id=script_revision_id,
            )
            raise

        # Split path into components
        path_parts = file.path.split("/")
        current_level = file_tree

        # Create directory structure
        for _, part in enumerate(path_parts[:-1]):
            if part not in current_level:
                current_level[part] = FileNode(type="directory", created_at=datetime.utcnow(), children={})
            elif current_level[part].type == "file":
                # Convert file to directory if needed
                current_level[part] = FileNode(type="directory", created_at=current_level[part].created_at, children={})

            current_level = current_level[part].children or {}

        # Add the file
        filename = path_parts[-1]
        current_level[filename] = FileNode(
            type="file",
            size=file_size,
            mime_type=file.mime_type,
            content_hash=f"sha256:{content_hash}",
            created_at=datetime.utcnow(),
        )

    return file_tree


async def execute_script(
    script_id: str,
    organization_id: str,
    background_tasks: BackgroundTasks | None = None,
) -> None:
    # TODO: assume the script only has one ScriptFile called main.py
    # step 1: get the script revision
    # step 2: get the script files
    # step 3: copy the script files to the local directory
    # step 4: execute the script

    # step 1: get the script revision
    script = await app.DATABASE.get_script(
        script_id=script_id,
        organization_id=organization_id,
    )
    if not script:
        raise ScriptNotFound(script_id=script_id)

    # step 2: get the script files
    script_files = await app.DATABASE.get_script_files(
        script_revision_id=script.script_revision_id, organization_id=organization_id
    )

    # step 3: copy the script files to the local directory
    for file in script_files:
        # retrieve the artifact
        if not file.artifact_id:
            continue
        artifact = await app.DATABASE.get_artifact_by_id(file.artifact_id, organization_id)
        if not artifact:
            LOG.error("Artifact not found", artifact_id=file.artifact_id, script_id=script_id)
            continue
        file_content = await app.ARTIFACT_MANAGER.retrieve_artifact(artifact)
        if not file_content:
            continue
        file_path = os.path.join(script.script_id, file.file_path)
        # create the directory if it doesn't exist
        os.makedirs(os.path.dirname(file_path), exist_ok=True)

        # Determine the encoding to use
        encoding = "utf-8"

        try:
            # Try to decode as text
            if file.mime_type and file.mime_type.startswith("text/"):
                # Text file - decode as string
                with open(file_path, "w", encoding=encoding) as f:
                    f.write(file_content.decode(encoding))
            else:
                # Binary file - write as bytes
                with open(file_path, "wb") as f:
                    f.write(file_content)
        except UnicodeDecodeError:
            # Fallback to binary mode if text decoding fails
            with open(file_path, "wb") as f:
                f.write(file_content)

    # step 4: execute the script
    if background_tasks:
        background_tasks.add_task(subprocess.run, ["python", f"{script.script_id}/main.py"])
    LOG.info("Script executed successfully", script_id=script_id)