# Django imports

from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

# Read project settings for Pydenticon, or fall-back to default values.

PYDENTICON_ROWS = getattr(settings, "PYDENTICON_ROWS", 5)

PYDENTICON_COLUMNS = getattr(settings, "PYDENTICON_COLUMNS", 5)

PYDENTICON_WIDTH = getattr(settings, "PYDENTICON_WIDTH", 200)

PYDENTICON_HEIGHT = getattr(settings, "PYDENTICON_HEIGHT", 200)

PYDENTICON_PADDING = getattr(settings, "PYDENTICON_PADDING", (20, 20, 20, 20))

PYDENTICON_FORMAT = getattr(settings, "PYDENTICON_FORMAT", "png")

PYDENTICON_FOREGROUND = getattr(settings, "PYDENTICON_FOREGROUND", ( "rgb(45,79,255)",

                                                                     "rgb(254,180,44)",

                                                                     "rgb(226,121,234)",

                                                                     "rgb(30,179,253)",

                                                                     "rgb(232,77,65)",

                                                                     "rgb(49,203,115)",

                                                                     "rgb(141,69,170)" ))

PYDENTICON_BACKGROUND = getattr(settings, "PYDENTICON_BACKGROUND", "rgb(224,224,224)")

# Validate the settings.

if not isinstance(PYDENTICON_ROWS, int) or PYDENTICON_ROWS <= 0:

    raise ImproperlyConfigured("Setting PYDENTICON_ROWS must be a positive integer.")

if not isinstance(PYDENTICON_COLUMNS, int) or PYDENTICON_COLUMNS <= 0:

    raise ImproperlyConfigured("Setting PYDENTICON_COLUMNS must be a positive integer.")

if not isinstance(PYDENTICON_WIDTH, int) or PYDENTICON_WIDTH <= 0:

    raise ImproperlyConfigured("Setting PYDENTICON_WIDTH must be a positive integer.")

if not isinstance(PYDENTICON_HEIGHT, int) or PYDENTICON_HEIGHT <= 0:

    raise ImproperlyConfigured("Setting PYDENTICON_HEIGHT must be a positive integer.")

if not all([isinstance(p, int) and p >= 0 for p in PYDENTICON_PADDING]) or len(PYDENTICON_PADDING) != 4:

    raise ImproperlyConfigured("Setting PYDENTICON_PADDING must be a 4-tuple where each element is a non-negative integer.")

if PYDENTICON_FORMAT not in ("png", "ascii"):

    raise ImproperlyConfigured("Setting PYDENTICON_FORMAT must be set to one of: 'png', 'ascii'.")

if not all([isinstance(f, str) for f in PYDENTICON_FOREGROUND]):

    raise ImproperlyConfigured("Setting PYDENTICON_FOREGROUND must be a tuple where each element is string representation of colour.")

if not isinstance(PYDENTICON_BACKGROUND, str):

    raise ImproperlyConfigured("Setting PYDENTICON_BACKGROUND must be a string representation of colour")

# Django imports.

from django.conf.urls import patterns, url

# Application imports.

from .views import image

urlpatterns = patterns(

    'django_pydenticon.views',

    # View for rendering an identicon image.

    url(r'^image/(?P<data>.+)$', image, name="image")

    )

# Third-party Python library imports.

from pydenticon import Generator

# Django imports.

from django.core.exceptions import SuspiciousOperation

from django.http import HttpResponse

from django.http import HttpResponseBadRequest

# Application imports.

from .settings import PYDENTICON_ROWS, PYDENTICON_COLUMNS, PYDENTICON_WIDTH, PYDENTICON_HEIGHT

from .settings import PYDENTICON_PADDING, PYDENTICON_FORMAT, PYDENTICON_FOREGROUND, PYDENTICON_BACKGROUND

def image(request, data):

    """

    Generates identicon image based on passed data.

    Arguments:

      data - Data which should be used for generating an identicon. This data

      will be used in order to create a digest which is used for generating the

      identicon. If the data passed is a hex digest already, the digest will be

      used as-is.

    Returns:

      Identicon image in raw format.

    """

    # Get image width, height, padding, and format from GET parameters, or

    # fall-back to default values from settings.

    try:

        width = int(request.GET.get("w", PYDENTICON_WIDTH))

    except ValueError:

        raise SuspiciousOperation("Identicon width must be a positive integer.")

    try:

        height = int(request.GET.get("h", PYDENTICON_HEIGHT))

    except ValueError:

        raise SuspiciousOperation("Identicon height must be a positive integer.")

    output_format = request.GET.get("f", PYDENTICON_FORMAT)

    try:

        padding = [int(p) for p in request.GET["p"].split(",")]

    except KeyError:

        padding = PYDENTICON_PADDING

    except ValueError:

        raise SuspiciousOperation("Identicon padding must consist out of 4 positive integers separated with commas.")

    # Validate the input parameters.

    if not isinstance(width, int) or width <= 0:

        raise ImproperlyConfigured("Identicon width must be a positive integer.")

    if not isinstance(height, int) or height <= 0:

        raise SuspiciousOperation("Identicon height must be a positive integer.")

    if not all([isinstance(p, int) and p >= 0 for p in padding]) or len(padding) != 4:

        raise SuspiciousOperation("Padding must be a 4-element tuple consisting out of positive integers.")

    # Set-up correct content type based on requested identicon format.

    if output_format == "png":

        content_type = "image/png"

    elif output_format == "ascii":

        content_type = "text/plain"

    else:

        raise SuspiciousOperation("Unsupported identicon format requested - '%s' % output_format")

    # Initialise a generator.

    generator = Generator(PYDENTICON_ROWS, PYDENTICON_COLUMNS)

    # Generate the identicion.

    content = generator.generate(data, width, height, padding=padding, output_format=output_format)

    # Create and return the response.

    response = HttpResponse(content, content_type=content_type)

    return response