import csv
import os

from builders import TextFileMazeBuilder

from solver import MazeSolver

from strategies import (
    BFSStrategy,
    DFSStrategy,
    AStarStrategy
)


# =========================================================
# Benchmark
# =========================================================

class BenchmarkRunner:

    def __init__(self):

        self.strategies = [
            ("BFS", BFSStrategy()),
            ("DFS", DFSStrategy()),
            ("A*", AStarStrategy()),
        ]

    # =====================================================
    # Run benchmark
    # =====================================================

    def run(
        self,
        maze_files: list[str],
        runs_per_test: int = 5
    ):

        results = []

        builder = TextFileMazeBuilder()

        for maze_file in maze_files:

            print()
            print(f"Testing: {maze_file}")

            maze = builder.build_from_file(
                maze_file
            )

            for strategy_name, strategy in self.strategies:

                total_time = 0
                total_visited = 0
                total_path_length = 0

                for _ in range(runs_per_test):

                    solver = MazeSolver(
                        maze,
                        strategy
                    )

                    path, stats = solver.solve()

                    total_time += stats.time_ms
                    total_visited += stats.visited_cells
                    total_path_length += stats.path_length

                avg_time = (
                    total_time / runs_per_test
                )

                avg_visited = (
                    total_visited / runs_per_test
                )

                avg_path_length = (
                    total_path_length / runs_per_test
                )

                result = {
                    "maze": maze_file,
                    "strategy": strategy_name,
                    "time_ms": round(avg_time, 3),
                    "visited_cells": int(avg_visited),
                    "path_length": int(avg_path_length),
                }

                results.append(result)

                print(
                    f"{strategy_name}: "
                    f"time={avg_time:.3f} ms, "
                    f"visited={avg_visited:.0f}, "
                    f"path={avg_path_length:.0f}"
                )

        self.save_to_csv(results)

    # =====================================================
    # Save CSV
    # =====================================================

    @staticmethod
    def save_to_csv(results):

        base_dir = os.path.dirname(__file__)

        csv_path = os.path.join(
            base_dir,
            "benchmark_results.csv"
        )

        with open(
            csv_path,
            "w",
            newline="",
            encoding="utf-8"
        ) as file:

            writer = csv.DictWriter(
                file,
                fieldnames=[
                    "maze",
                    "strategy",
                    "time_ms",
                    "visited_cells",
                    "path_length"
                ]
            )

            writer.writeheader()

            for row in results:

                writer.writerow(row)

        print()
        print(
            f"Results saved to: {csv_path}"
        )