import importlib
import importlib.util
import csv
import os
import logging

            if file_path.endswith('.pyc'):
                try:
                    file_path = importlib.util.source_from_cache(file_path)
                except ValueError:
                    pass
            if file_path.endswith('.py'):

def _run_worker_and_parse(cmd):
    result = subprocess.run(cmd, capture_output=True, text=True, check=True)
    try:
        lines = result.stdout.strip().splitlines()
        if not lines:
            raise ValueError("Worker produced no output on stdout.")
        data = json.loads(lines[-1])
        for key in ("time_ms", "peak_ram_mb", "loaded_modules", "loaded_lines"):
            if key not in data:
                raise KeyError(f"Missing key '{key}' in worker output")
        return data
    except (json.JSONDecodeError, IndexError, KeyError, ValueError) as parse_err:
        print(f"Error parsing worker output: {parse_err}", file=sys.stderr)
        print(f"Worker stdout:\\n{result.stdout}", file=sys.stderr)
        print(f"Worker stderr:\\n{result.stderr}", file=sys.stderr)
        raise parse_err

def run_master(iterations, target_module, cpu="0", csv_path=None):
    """Orchestrates the benchmark."""
    if iterations < 1:
        raise ValueError("Number of iterations must be at least 1.")
    times, memories = [], []
    loaded_modules_val, loaded_lines_val = 0, 0
    
    print(f"Profiling start... Running {iterations} cold-start iterations for {target_module}.")
    if cpu.lower() != "none":
        print(f"CPU Pinning enabled: Pinning processes to core {cpu} using taskset.")
    else:
        print("CPU Pinning disabled.")
    
    for i in range(iterations):
        cmd = []
        if cpu.lower() != "none":
            cmd += ["taskset", "-c", cpu]
        
        cmd += [sys.executable, __file__, "--worker", f"--module={target_module}"]
        
        try:
            data = _run_worker_and_parse(cmd)
            times.append(data["time_ms"])
            memories.append(data["peak_ram_mb"])
            loaded_modules_val = data["loaded_modules"]
            loaded_lines_val = data["loaded_lines"]
        except (subprocess.CalledProcessError, FileNotFoundError) as e:
            if cpu.lower() != "none" and i == 0:
                print("WARNING: taskset CPU pinning failed or is not available. Falling back to unpinned execution...")
                cmd = [sys.executable, __file__, "--worker", f"--module={target_module}"]
                try:
                    data = _run_worker_and_parse(cmd)
                    times.append(data["time_ms"])
                    memories.append(data["peak_ram_mb"])
                    loaded_modules_val = data["loaded_modules"]
                    loaded_lines_val = data["loaded_lines"]
                    cpu = "none"
                except subprocess.CalledProcessError as err:
                    print(f"Error in worker process:\n{err.stderr}", file=sys.stderr)
                    raise err
            else:
                if isinstance(e, subprocess.CalledProcessError):
                    print(f"Error in worker process:\n{e.stderr}", file=sys.stderr)
                raise e

        try:
            data = _run_worker_and_parse(cmd)
        except FileNotFoundError as e:
            if cpu.lower() != "none" and i == 0:
                print("WARNING: taskset CPU pinning is not available. Falling back to unpinned execution...")
                cpu = "none"
                cmd = [sys.executable, __file__, "--worker", f"--module={target_module}"]
                try:
                    data = _run_worker_and_parse(cmd)
                except subprocess.CalledProcessError as err:
                    print(f"Error in worker process:\\n{err.stderr}", file=sys.stderr)
                    raise err
            else:
                raise e
        except subprocess.CalledProcessError as e:
            print(f"Error in worker process:\\n{e.stderr}", file=sys.stderr)
            raise e

        times.append(data["time_ms"])
        memories.append(data["peak_ram_mb"])
        loaded_modules_val = data["loaded_modules"]
        loaded_lines_val = data["loaded_lines"]

def run_trace(target_module):
    """Generates importtime trace log and writes it to a file."""
    trace_file = f"import_trace_{target_module.replace('.', '_')}.log"
    print(f"Generating importtime trace log for {target_module} -> {trace_file}...")
    
    # We run: python -X importtime -c "import <module>"
    result = subprocess.run(
        [sys.executable, "-X", "importtime", "-c", f"import {target_module}"],
        capture_output=True, text=True
    )
    
    if result.returncode != 0:
        print(f"WARNING: Import failed with exit code {result.returncode}. The trace log may be incomplete or contain errors.", file=sys.stderr)
        if result.stdout:
            print(f"Worker stdout:\\n{result.stdout}", file=sys.stderr)
        if result.stderr:
            print(f"Worker stderr:\\n{result.stderr}", file=sys.stderr)
            
    with open(trace_file, "w", encoding="utf-8") as f:
        f.write(result.stderr)
        
    print(f"Trace log successfully written to {trace_file}")

def run_cprofile(target_module):
    """Runs cProfile in a clean subprocess to capture stack traces for latency."""
    import pstats
    
    prof_file = f"cprofile_{target_module.replace('.', '_')}.prof"
    print(f"Generating cProfile data for {target_module} -> {prof_file}...")
    
    # Run profiling in a clean subprocess to ensure cold-start
    result = subprocess.run(
        [sys.executable, "-m", "cProfile", "-o", prof_file, "-c", f"import importlib; importlib.import_module('{target_module}')"],
        capture_output=True, text=True
    )
    if result.returncode != 0:
        print(f"Error generating cProfile data:\n{result.stderr}", file=sys.stderr)
        return

    print(f"cProfile stats successfully written to {prof_file}")
    
    # Print top bottlenecks
    print("\n--- Top 15 functions by cumulative time ---")
    ps = pstats.Stats(prof_file).sort_stats(pstats.SortKey.CUMULATIVE)
    ps.print_stats(15)

    code = (
        "import tracemalloc\n"
        "import importlib\n"
        "tracemalloc.start()\n"
        f"importlib.import_module({json.dumps(target_module)})\n"
        "snapshot = tracemalloc.take_snapshot()\n"
        "tracemalloc.stop()\n"
        "top_stats = snapshot.statistics('lineno')\n"
        "for stat in top_stats[:15]:\n"
        "    print(stat)\n"
    )