"""
Generates a dictionary of ANSI escape codes.

http://en.wikipedia.org/wiki/ANSI_escape_code

Uses colorama as an optional dependency to support color on Windows
"""
import sys

try:
    import colorama
except ImportError:
    pass
else:
    if sys.platform == "win32":
        colorama.init(strip=False)

__all__ = ("escape_codes", "parse_colors")


# Returns escape codes from format codes
def esc(*x):
    return "\033[" + ";".join(x) + "m"


# The initial list of escape codes
escape_codes = {"reset": esc("0"), "bold": esc("01"), "thin": esc("02")}

# The color names
COLORS = ["black", "red", "green", "yellow", "blue", "purple", "cyan", "white"]

PREFIXES = [
    # Foreground without prefix
    ("3", ""),
    ("01;3", "bold_"),
    ("02;3", "thin_"),
    # Foreground with fg_ prefix
    ("3", "fg_"),
    ("01;3", "fg_bold_"),
    ("02;3", "fg_thin_"),
    # Background with bg_ prefix - bold/light works differently
    ("4", "bg_"),
    ("10", "bg_bold_"),
]

for prefix, prefix_name in PREFIXES:
    for code, name in enumerate(COLORS):
        escape_codes[prefix_name + name] = esc(prefix + str(code))


def parse_colors(sequence):
    """Return escape codes from a color sequence."""
    return "".join(escape_codes[n] for n in sequence.split(",") if n)
