# ml_module/tools/data_tools.py
import re
from typing import Dict, Optional

import pandas as pd
from agno.tools import Toolkit, tool

from ml_module.services.storage_service import MLStorageService
from ml_module.services.project_service import ProjectService
from ml_module.core.constants import ArtifactTypes, DEFAULT_SAMPLE_ROWS, StoragePaths
from ml_module.core.response_formatter import (
    FormattedResponse,
    Severity,
    make_text_response,
    metric_block,
    simple_table,
    simple_table_with_types,
    visualization_block,
    text_block,
)

class DataAnalysisToolkit(Toolkit):
    """A collection of safe tools for performing data analysis."""
    def __init__(
        self,
        storage_service: MLStorageService,
        user_id: str,
        project_id: str,
        project_service: Optional[ProjectService] = None,
    ):
        super().__init__(name="data_analysis_tools")
        self.storage = storage_service
        self.user_id = user_id
        self.project_id = project_id
        self.project_service = project_service

    def _get_base_path(self) -> str:
        return f"{self.user_id}/{self.project_id}"

    def _extract_version_from_path(self, path: str) -> Optional[int]:
        match = re.search(r"_v(\d+)", path)
        if match:
            try:
                return int(match.group(1))
            except ValueError:
                return None
        return None

    def _resolve_raw_version(self, dataset_path: str, default: int = 1) -> int:
        version = self._extract_version_from_path(dataset_path)
        if version is None and self.project_service:
            try:
                version = self.project_service.get_latest_version(self.user_id, self.project_id, "raw")
            except Exception:
                version = default
        return version or default

    @tool
    def get_data_summary(self, dataset_path: str) -> FormattedResponse:
        """
        Calculates and saves a high-level summary of the dataset. This includes
        shape (rows and columns), a list of column names, and data types for each column.
        This should be the VERY FIRST tool you use to understand the dataset.

        Args:
            dataset_path (str): The full path to the dataset file within project storage.

        Returns:
            FormattedResponse: Structured dataset summary with artifact reference.
        """
        try:
            df = self.storage.load_dataframe(dataset_path)
            summary = {
                "shape": {"rows": df.shape[0], "columns": df.shape[1]},
                "column_names": list(df.columns),
                "column_data_types": {col: str(dtype) for col, dtype in df.dtypes.items()},
            }
            output_path = f"{self._get_base_path()}/analysis/data_profile.json"
            info = self.storage.save_json(summary, output_path)

            if self.project_service:
                version = self._resolve_raw_version(dataset_path)
                info.metadata.update({"columns": summary["column_names"]})
                self.project_service.register_artifact(
                    self.user_id,
                    self.project_id,
                    ArtifactTypes.DATA_PROFILE,
                    version,
                    info,
                    version_scope="raw",
                    extra_metadata={"shape": summary["shape"]},
                )
            dtype_rows = [
                {"column": col, "dtype": dtype}
                for col, dtype in summary["column_data_types"].items()
            ]
            blocks = [
                metric_block("Rows", summary["shape"]["rows"]),
                metric_block("Columns", summary["shape"]["columns"]),
                simple_table_with_types(dtype_rows, caption="Column data types", block_id="column_dtypes"),
                text_block(f"Saved summary to `{output_path}`"),
            ]
            return FormattedResponse(
                blocks=blocks,
                summary="Data summary generated",
                correlation_id=info.path,
                done=True,
            )
        except Exception as e:
            error_response = make_text_response(
                f"Could not get data summary: {e}",
                severity=Severity.ERROR,
            )
            error_response.done = True
            return error_response

    @tool
    def get_missing_values_summary(self, dataset_path: str) -> FormattedResponse:
        """
        Analyzes the dataset for missing (null or NaN) values in each column and saves a
        report. This is a crucial step for assessing data quality.

        Args:
            dataset_path (str): The full path to the dataset file within project storage.

        Returns:
            FormattedResponse: Structured missing-value overview with artifact reference.
        """
        try:
            df = self.storage.load_dataframe(dataset_path)
            missing_values = df.isnull().sum()
            missing_summary = {
                "total_missing_values": int(missing_values.sum()),
                "missing_percentage": f"{(missing_values.sum() / (df.shape[0] * df.shape[1])):.2%}",
                "missing_values_per_column": {
                    col: int(count) for col, count in missing_values.items() if count > 0
                }
            }
            output_path = f"{self._get_base_path()}/analysis/missing_values_report.json"
            info = self.storage.save_json(missing_summary, output_path)

            if self.project_service:
                version = self._resolve_raw_version(dataset_path)
                info.metadata.update({"columns_with_missing": list(missing_summary["missing_values_per_column"].keys())})
                self.project_service.register_artifact(
                    self.user_id,
                    self.project_id,
                    ArtifactTypes.MISSING_VALUES,
                    version,
                    info,
                    version_scope="raw",
                    extra_metadata={
                        "total_missing": missing_summary["total_missing_values"],
                        "missing_percentage": missing_summary["missing_percentage"],
                    },
                )
            columns_with_missing = list(missing_summary["missing_values_per_column"].keys())
            table_rows = [
                {"column": col, "missing": count}
                for col, count in missing_summary["missing_values_per_column"].items()
            ]
            blocks = [
                metric_block(
                    "Total Missing",
                    missing_summary["total_missing_values"],
                    unit="cells",
                ),
                text_block(
                    f"Overall missing percentage: {missing_summary['missing_percentage']}",
                    severity=Severity.INFO,
                ),
                simple_table(table_rows, caption="Missing values per column", block_id="missing_values"),
                text_block(f"Saved missing-values report to `{output_path}`"),
            ]
            summary_text = (
                "No missing values detected"
                if not columns_with_missing
                else f"Missing values recorded for {len(columns_with_missing)} columns"
            )
            return FormattedResponse(
                blocks=blocks,
                summary=summary_text,
                correlation_id=info.path,
                done=True,
            )
        except Exception as e:
            error_response = make_text_response(
                f"Could not analyze missing values: {e}",
                severity=Severity.ERROR,
            )
            error_response.done = True
            return error_response

    @tool
    def save_sample_head(
        self,
        dataset_path: str,
        limit: Optional[int] = None,
        version: Optional[int] = None,
    ) -> FormattedResponse:
        """
        Saves the first N rows of the dataset as a JSON file for UI preview.
        Includes both the data sample and schema information.
        
        Args:
            dataset_path (str): The full path to the dataset file within project storage.
            limit (Optional[int]): Number of rows to sample (defaults to DEFAULT_SAMPLE_ROWS).
        
        Returns:
            FormattedResponse: Structured sample preview with artifact reference.
        """
        try:
            df = self.storage.load_dataframe(dataset_path)
            rows_to_sample = limit or DEFAULT_SAMPLE_ROWS
            resolved_version = version or self._resolve_raw_version(dataset_path)
            
            # Get sample data (first N rows)
            sample_df = df.head(rows_to_sample)
            
            # Create comprehensive sample data structure
            sample_data = {
                "dataset_info": {
                    "total_rows": len(df),
                    "total_columns": len(df.columns),
                    "sample_rows": len(sample_df),
                    "source_path": dataset_path
                },
                "schema": {
                    "columns": list(df.columns),
                    "dtypes": {col: str(dtype) for col, dtype in df.dtypes.items()},
                    "null_counts": {col: int(count) for col, count in df.isnull().sum().items()}
                },
                "sample_data": {
                    "columns": list(sample_df.columns),
                    "rows": sample_df.to_dict(orient="records")
                }
            }
            
            # Use versioned path from constants
            output_path = StoragePaths.SAMPLE_RAW_HEAD.format(
                user_id=self.user_id, 
                project_id=self.project_id, 
                version=resolved_version
            )
            info = self.storage.save_json(sample_data, output_path)

            if self.project_service:
                info.metadata.update({
                    "sample_rows": sample_data["dataset_info"].get("sample_rows"),
                    "total_rows": sample_data["dataset_info"].get("total_rows"),
                })
                self.project_service.register_artifact(
                    self.user_id,
                    self.project_id,
                    ArtifactTypes.SAMPLE_RAW_HEAD,
                    resolved_version,
                    info,
                    version_scope="raw",
                    extra_metadata={
                        "columns": sample_data["schema"].get("columns", []),
                    },
                )
            preview_rows = sample_df.head(min(rows_to_sample, 10)).to_dict(orient="records")
            blocks = [
                metric_block("Rows Sampled", len(sample_df)),
                metric_block("Total Rows", len(df)),
                simple_table_with_types(preview_rows, caption="First rows preview", block_id="sample_preview"),
                text_block(f"Sample saved to `{output_path}`"),
            ]
            return FormattedResponse(
                blocks=blocks,
                summary=f"Saved sample head (first {len(sample_df)} rows)",
                correlation_id=info.path,
                done=True,
            )
        except Exception as e:
            error_response = make_text_response(
                f"Could not save dataset sample: {e}",
                severity=Severity.ERROR,
            )
            error_response.done = True
            return error_response