#!/usr/bin/env python

from __future__ import print_function

import argparse
import math
import os
import os.path
import re
import subprocess
import sys

# Runs the tests.
WREN_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
BENCHMARK_DIR = os.path.join(WREN_DIR, 'benchmark')

# How many times to run a given benchmark.
NUM_TRIALS = 10

BENCHMARKS = []

def BENCHMARK(name, pattern):
  regex = re.compile(pattern + "\n" + r"elapsed: (\d+\.\d+)", re.MULTILINE)
  BENCHMARKS.append([name, regex, None])

BENCHMARK("binary_trees", """stretch tree of depth 13 check: -1
8192 trees of depth 4 check: -8192
2048 trees of depth 6 check: -2048
512 trees of depth 8 check: -512
128 trees of depth 10 check: -128
32 trees of depth 12 check: -32
long lived tree of depth 12 check: -1""")

BENCHMARK("delta_blue", "7032700")

BENCHMARK("fib", r"""317811
317811
317811
317811
317811""")

BENCHMARK("for", r"""499999500000""")

BENCHMARK("method_call", r"""true
false""")

BENCHMARK("map_numeric", r"""500000500000""")

BENCHMARK("map_string", r"""3645600""")

LANGUAGES = [
  ("wren",           [os.path.join(WREN_DIR, 'wren')], ".wren"),
  ("lua",            ["lua"],                          ".lua"),
  ("luajit (-joff)", ["luajit", "-joff"],              ".lua"),
  ("python",         ["python"],                       ".py"),
  ("python3",        ["python3"],                      ".py"),
  ("ruby",           ["ruby"],                         ".rb")
]

results = {}

def green(text):
  if sys.platform == 'win32':
    return text
  return '\033[32m' + text + '\033[0m'

def red(text):
  if sys.platform == 'win32':
    return text
  return '\033[31m' + text + '\033[0m'

def yellow(text):
  if sys.platform == 'win32':
    return text
  return '\033[33m' + text + '\033[0m'


def get_score(time):
  """
  Converts time into a "score". This is the inverse of the time with an
  arbitrary scale applied to get the number in a nice range. The goal here is
  to have benchmark results where faster = bigger number.
  """
  return 1000.0 / time


def run_trial(benchmark, language):
  """Runs one benchmark one time for one language."""
  args = []
  args.extend(language[1])
  args.append(os.path.join(BENCHMARK_DIR, benchmark[0] + language[2]))
  try:
    out = subprocess.check_output(args, universal_newlines=True)
  except OSError:
    print('Interpreter was not found')
    return None
  match = benchmark[1].match(out)
  if match:
    return float(match.group(1))
  else:
    print("Incorrect output:")
    print(out)
    return None


def run_benchmark_language(benchmark, language, benchmark_result):
  """
  Runs one benchmark for a number of trials for one language.

  Adds the result to benchmark_result, which is a map of language names to
  results.
  """

  name = "{0} - {1}".format(benchmark[0], language[0])
  print("{0:30s}".format(name), end=' ')

  if not os.path.exists(os.path.join(
      BENCHMARK_DIR, benchmark[0] + language[2])):
    print("No implementation for this language")
    return

  times = []
  for i in range(0, NUM_TRIALS):
    time = run_trial(benchmark, language)
    if not time:
      return
    times.append(time)
    sys.stdout.write(".")

  best = min(times)
  score = get_score(best)

  comparison = ""
  if language[0] == "wren":
    if benchmark[2] != None:
      ratio = 100 * score / benchmark[2]
      comparison =  "{:6.2f}% relative to baseline".format(ratio)
      if ratio > 105:
        comparison = green(comparison)
      if ratio < 95:
        comparison = red(comparison)
    else:
      comparison = "no baseline"
  else:
    # Hack: assumes wren gets run first.
    wren_score = benchmark_result["wren"]["score"]
    ratio = 100.0 * wren_score / score
    comparison =  "{:6.2f}%".format(ratio)
    if ratio > 105:
      comparison = green(comparison)
    if ratio < 95:
      comparison = red(comparison)

  print(" {:5.0f}  {:4.2f}s  {:s}".format(score, best, comparison))

  benchmark_result[language[0]] = {
    "desc": name,
    "times": times,
    "score": score
  }

  return score


def run_benchmark(benchmark, languages):
  """Runs one benchmark for the given languages (or all of them)."""

  benchmark_result = {}
  results[benchmark[0]] = benchmark_result

  num_languages = 0
  for language in LANGUAGES:
    if not languages or language[0] in languages:
      num_languages += 1
      run_benchmark_language(benchmark, language, benchmark_result)

  if num_languages > 1:
    graph_results(benchmark_result)


def graph_results(benchmark_result):
  print()

  INCREMENT = {
    '-': 'o',
    'o': 'O',
    'O': '0',
    '0': '0'
  }

  # Scale everything by the highest score.
  highest = 0
  for language, result in benchmark_result.items():
    score = get_score(min(result["times"]))
    if score > highest: highest = score

  print("{0:30s}0 {1:66.0f}".format("", highest))
  for language, result in benchmark_result.items():
    line = ["-"] * 68
    for time in result["times"]:
      index = int(get_score(time) / highest * 67)
      line[index] = INCREMENT[line[index]]
    print("{0:30s}{1}".format(result["desc"], "".join(line)))
  print()


def read_baseline():
  if os.path.exists("baseline.txt"):
    with open("baseline.txt") as f:
      for line in f.readlines():
        name, best = line.split(",")
        for benchmark in BENCHMARKS:
          if benchmark[0] == name:
            benchmark[2] = float(best)


def generate_baseline():
  print("generating baseline")
  baseline_text = ""
  for benchmark in BENCHMARKS:
    best = run_benchmark_language(benchmark, LANGUAGES[0], {})
    baseline_text += ("{},{}\n".format(benchmark[0], best))

  # Write them to a file.
  with open("baseline.txt", 'w') as out:
    out.write(baseline_text)


def print_html():
  '''Print the results as an HTML chart.'''

  def print_benchmark(benchmark, name):
    print('<h3>{}</h3>'.format(name))
    print('<table class="chart">')

    # Scale everything by the highest time.
    highest = 0
    for language, result in results[benchmark].items():
      time = min(result["times"])
      if time > highest: highest = time

    languages = sorted(results[benchmark].keys(),
        key=lambda lang: results[benchmark][lang]["score"], reverse=True)

    for language in languages:
      result = results[benchmark][language]
      time = float(min(result["times"]))
      ratio = int(100 * time / highest)
      css_class = "chart-bar"
      if language == "wren":
        css_class += " wren"
      print('  <tr>')
      print('    <th>{}</th><td><div class="{}" style="width: {}%;">{:4.2f}s&nbsp;</div></td>'.format(
          language, css_class, ratio, time))
      print('  </tr>')
    print('</table>')

  print_benchmark("method_call", "Method Call")
  print_benchmark("delta_blue", "DeltaBlue")
  print_benchmark("binary_trees", "Binary Trees")
  print_benchmark("fib", "Recursive Fibonacci")


def main():
  parser = argparse.ArgumentParser(description="Run the benchmarks")
  parser.add_argument("benchmark", nargs='?',
      default="all",
      help="The benchmark to run")
  parser.add_argument("--generate-baseline",
      action="store_true",
      help="Generate a baseline file")
  parser.add_argument("-l", "--language",
      action="append",
      help="Which language(s) to run benchmarks for")
  parser.add_argument("--output-html",
      action="store_true",
      help="Output the results chart as HTML")

  args = parser.parse_args()

  if args.generate_baseline:
    generate_baseline()
    return

  read_baseline()

  # Run the benchmarks.
  for benchmark in BENCHMARKS:
    if benchmark[0] == args.benchmark or args.benchmark == "all":
      run_benchmark(benchmark, args.language)

  if args.output_html:
    print_html()


main()