from django.core.urlresolvers import reverse
from django.http import HttpResponse, HttpResponseNotFound
from eve_proxy.models import CachedDocument

def retrieve_xml(request):
    """
    A view that forwards EVE API requests through the cache system, either
    retrieving a cached document or querying and caching as needed.
    """
    # This is the URL path (minus the parameters).
    url_path = request.META['PATH_INFO'].replace(reverse('eve_proxy.views.retrieve_xml'),"/")
    # The parameters attached to the end of the URL path.

    if request.method == 'POST':
        p = request.POST
    else:
        p = request.GET

    # Convert the QuerySet object into a dict
    params = {}
    for key,value in p.items():
        params[key] = value

    if url_path == '/' or url_path == '':
        # If they don't provide any kind of query, shoot a quick error message.
        return HttpResponse('No API query specified.')
    
    if not 'service' in params:
        return HttpResponse('No Service ID provided.')

    # The query system will retrieve a cached_doc that was either previously
    # or newly cached depending on cache intervals.
    cached_doc = CachedDocument.objects.api_query(url_path, params)
    # Return the document's body as XML.

    if cached_doc:
        return HttpResponse(cached_doc.body, mimetype='text/xml')

    return HttpResponseNotFound('Error retrieving the document')