from locations.models import *
from math import *

# TODO: Authentication!!!
# TODO: Better error handling

def GetLocationList():
	"""Returns a list of locations."""

	locations = Location.objects.all()		

	results = []

	for location in locations:
		results.append({ 
			'id': location.id, 
			'lat': location.lat, 
			'lon': location.lon, 
			'name': location.name, 
			'locname': location.locname, 
			'website': location.website
		})

	return results

def GetLocationDetails(locationid):
	location = Location.objects.get(id=locationid)
	if location.id:
		vals = {"location": location}
		equipcnt = location.equipment_set.count()
		if equipcnt > 0:
			equip = []
			for equipment in location.equipment_set.iterator():
				caps = []
				for capability in equipment.type.capabilities.iterator():
					caps.append(capability.name)
				equip.append({"type": equipment.type.name, "maker": equipment.type.maker, "capabilities": caps, "notes": equipment.notes})
			vals['equipment'] = equip
		
		return vals
	else:
		return {}

def GetEquipmentTypes():
	equiptypes = EquipmentType.objects.all()
	
	results = []
	for e in equiptypes.iterator:
		caps = []
		for capability in e.capabilities.iterator():
			caps.append(capability.name)
		results.append({'name': e.name, 'maker': e.maker, 'capabilities': caps})
	
	return results
	
def GetCapabilities():
	caps = EquipmentCapability.objects.all()
	ret = []
	for a in caps.iterator():
		ret.append({'id': a.id, 'name': a.name})
	return ret
	
def AddEquipmentType(name, maker, capabilities):
	# Register an equipment type
	et = EquipmentType(name=name, maker=maker)
	et.save()
	for a in capabilities:
		if type(a) is int:
			et.capabilities.add(a)
	et.save()
	return {'saved': True}
	
def AddEquipment(locationid, equipmenttype, notes):
	# Register equipment
	eq = Equipment(type=equipmenttype, location=locationid, notes=notes)
	eq.save()
	return {'saved': True}

def AddLocation(name, locname, lat, lon, website):
	# Add a location.
	manager = 1
	# FIXME: Here we should make manager be the same as the authed user.
	location = Location(name=name, locname=locname, lat=lat, lon=lon, website=website, manager=manager)
	location.save()
	return {'location': location, 'saved': True}
	
def SetLocation(locationid, name, locname, lat, lon, website):
	location = Location(locationid=locationid)
	if name:		location.name = name
	if locname:	location.locname = locname
	if latitude:	location.latitude = lat
	if longitude: 	location.longitude = lon
	if website:	location.website = website
	location.save()
	
def AddCapability(capability):
	# Add a capability class
	cap = EquipmentCapability(name=capability)
	cap.save()
	return {'saved': True, 'id': cap.id}
	
def FindEquipmentByCapability(capid):
	# Return a list of equipment, and each equipment type contains a list of locations where it exists.
	
	return {}
	


def Haversine(lon1, lat1, lon2, lat2):
	# TODO: Move this to some utilities thing?
	"""
	Find the distance in km between two points on the surface of the earth
	using the haversine formula. http://mathforum.org/library/drmath/view/51879.html
	http://www.mpi.nl/world/persons/private/micdunn/misc/haversine.py
	"""
	lon1 = radians(lon1)
	lon2 = radians(lon2)
	lat1 = radians(lat1)
	lat2 = radians(lat2)
	dlon = lon2 - lon1
	dlat = lat2 - lat1

	a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
	c = 2 * atan2(sqrt(a), sqrt(1-a)) 
	km = 6367 * c 
	return km