import logging
import os
import time
from typing import Any

from app.service.task.base_task import BaseTask
from app.service.task.task_param import TaskParam
from app.service.task.task_result import TaskResult
from app.util.file_util import generate_unique_filename, base64_to_file

logger = logging.getLogger(__name__)


class Base64DecodeTask(BaseTask):
    def get_type(self) -> str:
        return "base64_decode"

    def execute(self, param: TaskParam) -> TaskResult:
        try:
            files_obj = param.inputs.get("files")
            files: list[str] = files_obj if isinstance(files_obj, list) else []

            if not files:
                return TaskResult.failure("No files provided for base64 decoding")
            if not param.workspace:
                return TaskResult.failure("Workspace path is not provided")

            logger.info("[base64_decode] Starting: %d files to decode", len(files))
            t0 = time.time()
            decoded_files: list[str] = []
            for i, b64 in enumerate(files):
                try:
                    name = generate_unique_filename(".png")
                    rel_path = os.path.join(param.step_id, name)
                    abs_path = os.path.join(param.workspace, rel_path)
                    base64_to_file(b64, abs_path)
                    decoded_files.append(rel_path)
                    logger.info("[base64_decode] Decoded file %d/%d -> %s (base64_len=%d)",
                                 i + 1, len(files), rel_path, len(b64))
                except Exception as e:
                    logger.error("[base64_decode] Failed to decode file %d/%d: %s", i + 1, len(files), e)

            if not decoded_files:
                return TaskResult.failure("No files were successfully decoded")

            logger.info("[base64_decode] Completed: %d/%d decoded in %.2fs",
                         len(decoded_files), len(files), time.time() - t0)
            return TaskResult.success({"files": decoded_files})
        except Exception as e:
            logger.error("[base64_decode] Error: %s", e, exc_info=True)
            return TaskResult.failure(f"Base64 decoding failed: {e}")