#!/usr/bin/env python3

# This file is part of the MicroPython project, http://micropython.org/
# The MIT License (MIT)
# Copyright (c) 2019 Damien P. George

import os
import subprocess
import sys
import time
import argparse
from glob import glob
from rich.live import Live
from rich.console import Console
from rich.table import Table

sys.path.append("../tools")
import pyboard

# Paths for host executables
if os.name == "nt":
    CPYTHON3 = os.getenv("MICROPY_CPYTHON3", "python3.exe")
    MICROPYTHON = os.getenv("MICROPY_MICROPYTHON", "../ports/windows/micropython.exe")
else:
    CPYTHON3 = os.getenv("MICROPY_CPYTHON3", "python3")
    MICROPYTHON = os.getenv("MICROPY_MICROPYTHON", "../ports/unix/micropython")

PYTHON_TRUTH = CPYTHON3

BENCH_SCRIPT_DIR = "perf_bench/"


def compute_stats(lst):
    avg = 0
    var = 0
    for x in lst:
        avg += x
        var += x * x
    avg /= len(lst)
    var = max(0, var / len(lst) - avg**2)
    return avg, var**0.5


def run_script_on_target(target, script, run_command=None):
    output = b""
    err = None

    if isinstance(target, pyboard.Pyboard):
        # Run via pyboard interface
        try:
            target.enter_raw_repl()
            start_ts = time.monotonic_ns()
            output = target.exec_(script)
            if run_command:
                start_ts = time.monotonic_ns()
                output = target.exec_(run_command)
            end_ts = time.monotonic_ns()
        except pyboard.PyboardError as er:
            end_ts = time.monotonic_ns()
            err = er
        finally:
            target.exit_raw_repl()
    else:
        # Run local executable
        try:
            if run_command:
                script += run_command
            start_ts = time.monotonic_ns()
            p = subprocess.run(
                target, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, input=script
            )
            end_ts = time.monotonic_ns()
            output = p.stdout
        except subprocess.CalledProcessError as er:
            end_ts = time.monotonic_ns()
            err = er

    return str(output.strip(), "ascii"), err, (end_ts - start_ts) // 1000


def run_feature_test(target, test):
    with open("feature_check/" + test + ".py", "rb") as f:
        script = f.read()
    output, err, _ = run_script_on_target(target, script)
    if err is None:
        return output
    else:
        return "CRASH: %r" % err


def run_benchmark_on_target(target, script, run_command=None):
    output, err, runtime_us = run_script_on_target(target, script, run_command)
    if err is None:
        time, norm, result = output.split(None, 2)
        try:
            return int(time), int(norm), result, runtime_us
        except ValueError:
            return -1, -1, "CRASH: %r" % output, runtime_us
    else:
        return -1, -1, "CRASH: %r" % err, runtime_us


def run_benchmarks(console, target, param_n, param_m, n_average, test_list):
    skip_complex = run_feature_test(target, "complex") != "complex"
    skip_native = run_feature_test(target, "native_check") != "native"

    table = Table(show_header=True)
    table.add_column("Test")
    table.add_column("Time", justify="right")
    table.add_column("Score", justify="right")
    table.add_column("Ref Time", justify="right")

    live = Live(table, console=console)
    live.start()

    for test_file in sorted(test_list):
        # print(test_file + ": ", end="")

        # Check if test should be skipped
        skip = (
            skip_complex
            and test_file.find("bm_fft") != -1
            or skip_native
            and test_file.find("viper_") != -1
        )
        if skip:
            print("skip")
            table.add_row(test_file, *(["skip"] * 6))
            continue

        # Create test script
        with open(test_file, "rb") as f:
            test_script = f.read()
        with open(BENCH_SCRIPT_DIR + "benchrun.py", "rb") as f:
            test_script += f.read()
        bm_run = b"bm_run(%u, %u)\n" % (param_n, param_m)

        # Write full test script if needed
        if 0:
            with open("%s.full" % test_file, "wb") as f:
                f.write(test_script)

        # Run MicroPython a given number of times
        times = []
        runtimes = []
        scores = []
        error = None
        result_out = None
        for _ in range(n_average):
            self_time, norm, result, runtime_us = run_benchmark_on_target(
                target, test_script, bm_run
            )
            if self_time < 0 or norm < 0:
                error = result
                break
            if result_out is None:
                result_out = result
            elif result != result_out:
                error = "FAIL self"
                break
            times.append(self_time)
            runtimes.append(runtime_us)
            scores.append(1e6 * norm / self_time)

        # Check result against truth if needed
        if error is None and result_out != "None":
            _, _, result_exp, _ = run_benchmark_on_target(PYTHON_TRUTH, test_script, bm_run)
            if result_out != result_exp:
                error = "FAIL truth"

        if error is not None:
            print(test_file, error)
            if error == "no matching params":
                table.add_row(test_file, *([None] * 3))
            else:
                table.add_row(test_file, *(["error"] * 3))
        else:
            t_avg, t_sd = compute_stats(times)
            r_avg, r_sd = compute_stats(runtimes)
            s_avg, s_sd = compute_stats(scores)
            # print(
            #     "{:.2f} {:.4f} {:.2f} {:.4f} {:.2f} {:.4f}".format(
            #         t_avg, 100 * t_sd / t_avg, s_avg, 100 * s_sd / s_avg, r_avg, 100 * r_sd / r_avg
            #     )
            # )
            table.add_row(
                test_file,
                f"{t_avg:.2f}±{100 * t_sd / t_avg:.1f}%",
                f"{s_avg:.2f}±{100 * s_sd / s_avg:.1f}%",
                f"{r_avg:.2f}±{100 * r_sd / r_avg:.1f}%",
            )
            if 0:
                print("  times: ", times)
                print("  scores:", scores)

        live.update(table, refresh=True)
    live.stop()


def parse_output(filename):
    with open(filename) as f:
        params = f.readline()
        n, m, _ = params.strip().split()
        n = int(n.split("=")[1])
        m = int(m.split("=")[1])
        data = []
        for l in f:
            if l.find(": ") != -1 and l.find(": skip") == -1 and l.find("CRASH: ") == -1:
                name, values = l.strip().split(": ")
                values = tuple(float(v) for v in values.split())
                data.append((name,) + values)
    return n, m, data


def compute_diff(file1, file2, diff_score):
    # Parse output data from previous runs
    n1, m1, d1 = parse_output(file1)
    n2, m2, d2 = parse_output(file2)

    # Print header
    if diff_score:
        print("diff of scores (higher is better)")
    else:
        print("diff of microsecond times (lower is better)")
    if n1 == n2 and m1 == m2:
        hdr = "N={} M={}".format(n1, m1)
    else:
        hdr = "N={} M={} vs N={} M={}".format(n1, m1, n2, m2)
    print(
        "{:24} {:>10} -> {:>10}   {:>10}   {:>7}% (error%)".format(
            hdr, file1, file2, "diff", "diff"
        )
    )

    # Print entries
    while d1 and d2:
        if d1[0][0] == d2[0][0]:
            # Found entries with matching names
            entry1 = d1.pop(0)
            entry2 = d2.pop(0)
            name = entry1[0].rsplit("/")[-1]
            av1, sd1 = entry1[1 + 2 * diff_score], entry1[2 + 2 * diff_score]
            av2, sd2 = entry2[1 + 2 * diff_score], entry2[2 + 2 * diff_score]
            sd1 *= av1 / 100  # convert from percent sd to absolute sd
            sd2 *= av2 / 100  # convert from percent sd to absolute sd
            av_diff = av2 - av1
            sd_diff = (sd1**2 + sd2**2) ** 0.5
            percent = 100 * av_diff / av1
            percent_sd = 100 * sd_diff / av1
            print(
                "{:24} {:10.2f} -> {:10.2f} : {:+10.2f} = {:+7.3f}% (+/-{:.2f}%)".format(
                    name, av1, av2, av_diff, percent, percent_sd
                )
            )
        elif d1[0][0] < d2[0][0]:
            d1.pop(0)
        else:
            d2.pop(0)


def main():
    cmd_parser = argparse.ArgumentParser(description="Run benchmarks for MicroPython")
    cmd_parser.add_argument(
        "-t", "--diff-time", action="store_true", help="diff time outputs from a previous run"
    )
    cmd_parser.add_argument(
        "-s", "--diff-score", action="store_true", help="diff score outputs from a previous run"
    )
    cmd_parser.add_argument(
        "-p", "--pyboard", action="store_true", help="run tests via pyboard.py"
    )
    cmd_parser.add_argument(
        "-d", "--device", default="/dev/ttyACM0", help="the device for pyboard.py"
    )
    cmd_parser.add_argument("-a", "--average", default="8", help="averaging number")
    cmd_parser.add_argument(
        "--emit", default="bytecode", help="MicroPython emitter to use (bytecode or native)"
    )
    cmd_parser.add_argument("N", nargs=1, help="N parameter (approximate target CPU frequency)")
    cmd_parser.add_argument("M", nargs=1, help="M parameter (approximate target heap in kbytes)")
    cmd_parser.add_argument("files", nargs="*", help="input test files")
    args = cmd_parser.parse_args()

    if args.diff_time or args.diff_score:
        compute_diff(args.N[0], args.M[0], args.diff_score)
        sys.exit(0)

    # N, M = 50, 25 # esp8266
    # N, M = 100, 100 # pyboard, esp32
    # N, M = 1000, 1000 # PC
    N = int(args.N[0])
    M = int(args.M[0])
    n_average = int(args.average)

    if args.pyboard:
        target = pyboard.Pyboard(args.device)
        target.enter_raw_repl()
    else:
        target = [MICROPYTHON, "-X", "emit=" + args.emit]

    if len(args.files) == 0:
        tests_skip = ("benchrun.py",)
        if M <= 25:
            # These scripts are too big to be compiled by the target
            tests_skip += ("bm_chaos.py", "bm_hexiom.py", "misc_raytrace.py")
        tests = sorted(
            BENCH_SCRIPT_DIR + test_file
            for test_file in os.listdir(BENCH_SCRIPT_DIR)
            if test_file.endswith(".py") and test_file not in tests_skip
        )
    else:
        tests = sorted(args.files)

    console = Console()
    print("N={} M={} n_average={}".format(N, M, n_average))

    run_benchmarks(console, target, N, M, n_average, tests)

    if isinstance(target, pyboard.Pyboard):
        target.exit_raw_repl()
        target.close()


if __name__ == "__main__":
    main()