#!/usr/bin/env python

from lib.core import Segment
from lib.renderers import SegmentRenderer


class VimSegmentRenderer(SegmentRenderer):
	'''Powerline vim segment renderer.
	'''
	def __init__(self):
		self.hl_groups = {}

	def hl(self, fg=None, bg=None, attr=None):
		'''Highlight a segment.

		If an argument is None, the argument is ignored. If an argument is
		False, the argument is reset to the terminal defaults. If an argument
		is a valid color or attribute, it's added to the vim highlight group.
		'''
		hl_group = {
			'ctermfg': 'NONE',
			'guifg': 'NONE',
			'ctermbg': 'NONE',
			'guibg': 'NONE',
			'attr': ['NONE'],
		}

		# We don't need to explicitly reset attributes in vim, so skip those calls
		if not attr and not bg and not fg:
			return ''

		if fg is not None and fg is not False:
			hl_group['ctermfg'] = fg[0]
			hl_group['guifg'] = fg[1]

		if bg is not None and bg is not False:
			hl_group['ctermbg'] = bg[0]
			hl_group['guibg'] = bg[1]

		if attr is not None and attr is not False and attr != 0:
			hl_group['attr'] = []
			if attr & Segment.ATTR_BOLD:
				hl_group['attr'].append('bold')
			if attr & Segment.ATTR_ITALIC:
				hl_group['attr'].append('italic')
			if attr & Segment.ATTR_UNDERLINE:
				hl_group['attr'].append('underline')

		hl_group_name = 'Pl_{ctermfg}_{guifg}_{ctermbg}_{guibg}_{attr}'.format(
			ctermfg=hl_group['ctermfg'],
			guifg=hl_group['guifg'],
			ctermbg=hl_group['ctermbg'],
			guibg=hl_group['guibg'],
			attr=''.join(attr[0] for attr in hl_group['attr']),
		)

		self.hl_groups[hl_group_name] = hl_group

		return '%#{0}#'.format(hl_group_name)