"""WizardKit: Graph Functions"""
# vim: sts=2 sw=2 ts=2

import logging

from wk.ui.cli import color_string # TODO: This is lazy


# STATIC VARIABLES
LOG = logging.getLogger(__name__)
GRAPH_HORIZONTAL = ('▁', '▂', '▃', '▄', '▅', '▆', '▇', '█')
GRAPH_VERTICAL = (
    '▏',    '▎',    '▍',    '▌',
    '▋',    '▊',    '▉',    '█',
    '█▏',   '█▎',   '█▍',   '█▌',
    '█▋',   '█▊',   '█▉',   '██',
    '██▏',  '██▎',  '██▍',  '██▌',
    '██▋',  '██▊',  '██▉',  '███',
    '███▏', '███▎', '███▍', '███▌',
    '███▋', '███▊', '███▉', '████',
  )
# SCALE_STEPS: These scales allow showing differences between HDDs and SSDs
#              on the same graph.
SCALE_STEPS = {
  8:  [2**(0.56*(x+1))+(16*(x+1)) for x in range(8)],
  16: [2**(0.56*(x+1))+(16*(x+1)) for x in range(16)],
  32: [2**(0.56*(x+1)/2)+(16*(x+1)/2) for x in range(32)],
  }
# THRESHOLDS: These are the rate_list (in MB/s) used to color graphs
THRESH_FAIL =          65 * 1024**2
THRESH_WARN =         135 * 1024**2
THRESH_GREAT =        750 * 1024**2


# Functions
def generate_horizontal_graph(rate_list, graph_width=40, oneline=False):
  """Generate horizontal graph from rate_list, returns list."""
  graph = ['', '', '', '']
  scale = 8 if oneline else 32

  # Build graph
  for rate in merge_rates(rate_list, graph_width=graph_width):
    step = get_graph_step(rate, scale=scale)

    # Set color
    rate_color = None
    if rate < THRESH_FAIL:
      rate_color = 'RED'
    elif rate < THRESH_WARN:
      rate_color = 'YELLOW'
    elif rate > THRESH_GREAT:
      rate_color = 'GREEN'

    # Build graph
    full_block = color_string((GRAPH_HORIZONTAL[-1],), (rate_color,))
    if step >= 24:
      graph[0] += color_string((GRAPH_HORIZONTAL[step-24],), (rate_color,))
      graph[1] += full_block
      graph[2] += full_block
      graph[3] += full_block
    elif step >= 16:
      graph[0] += ' '
      graph[1] += color_string((GRAPH_HORIZONTAL[step-16],), (rate_color,))
      graph[2] += full_block
      graph[3] += full_block
    elif step >= 8:
      graph[0] += ' '
      graph[1] += ' '
      graph[2] += color_string((GRAPH_HORIZONTAL[step-8],), (rate_color,))
      graph[3] += full_block
    else:
      graph[0] += ' '
      graph[1] += ' '
      graph[2] += ' '
      graph[3] += color_string((GRAPH_HORIZONTAL[step],), (rate_color,))

  # Done
  if oneline:
    graph = graph[-1:]
  return graph


def get_graph_step(rate, scale=16):
  """Get graph step based on rate and scale, returns int."""
  rate_in_mb = rate / (1024**2)
  step = 0

  # Iterate over scale_steps backwards
  for _r in range(scale-1, -1, -1):
    if rate_in_mb >= SCALE_STEPS[scale][_r]:
      step = _r
      break

  # Done
  return step


def merge_rates(rates, graph_width=40):
  """Merge rates to have entries equal to the width, returns list."""
  merged_rates = []
  offset = 0
  slice_width = int(len(rates) / graph_width)

  # Merge rates
  for _i in range(graph_width):
    merged_rates.append(sum(rates[offset:offset+slice_width])/slice_width)
    offset += slice_width

  # Done
  return merged_rates


def vertical_graph_line(percent, rate, scale=32):
  """Build colored graph string using thresholds, returns str."""
  color_bar = None
  color_rate = None
  step = get_graph_step(rate, scale=scale)

  # Set colors
  if rate < THRESH_FAIL:
    color_bar = 'RED'
    color_rate = 'YELLOW'
  elif rate < THRESH_WARN:
    color_bar = 'YELLOW'
    color_rate = 'YELLOW'
  elif rate > THRESH_GREAT:
    color_bar = 'GREEN'
    color_rate = 'GREEN'

  # Build string
  line = color_string(
    strings=(
      f'{percent:5.1f}%',
      f'{GRAPH_VERTICAL[step]:<4}',
      f'{rate/(1000**2):6.1f} MB/s',
      ),
    colors=(
      None,
      color_bar,
      color_rate,
      ),
    sep='  ',
    )

  # Done
  return line


if __name__ == '__main__':
  print("This file is not meant to be called directly.")