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var Joi = require('joi'); | |
/* | |
* Test listings | |
*/ | |
let listings = [ | |
{ | |
'id':4522, | |
'listing_price_cents':33700000, | |
'bedrooms':3, | |
'bathrooms':2.0, | |
'square_footage':2109, | |
'published':true, | |
'year_built':2002, | |
'lonlat':'POINT (-96.858753 33.116399)', | |
'pool_type':[ | |
], | |
'parking_type':[ | |
'garage_attached' | |
] | |
}, | |
{ | |
'id':4528, | |
'listing_price_cents':28200000, | |
'bedrooms':1, | |
'bathrooms':2.0, | |
'square_footage':1579, | |
'published':false, | |
'year_built':1973, | |
'lonlat':'POINT (-112.021649 33.606579)', | |
'pool_type':[ | |
'private', | |
'public' | |
], | |
'parking_type':[ | |
'garage_attached' | |
] | |
} | |
]; | |
/* | |
* Listing filter | |
*/ | |
let ListingFilter = { | |
/* Assumes array schema is correct */ | |
filter: function(listings, constraints) { | |
ListingFilter.validateConstraints(constraints); | |
return listings.filter(listing => { | |
var result = true; | |
constraints.forEach(constraint => { | |
let value = listing[constraint.attribute]; | |
if (constraint.minValue !== undefined) { | |
result = result && ListingFilter.minValue(value, constraint.minValue); | |
} | |
if (constraint.maxValue !== undefined) { | |
result = result && ListingFilter.maxValue(value, constraint.maxValue); | |
} | |
if (constraint.equalToValue !== undefined) { | |
result = result && ListingFilter.equalToValue(value, constraint.equalToValue); | |
} | |
if (constraint.containsOneOf !== undefined) { | |
result = result && ListingFilter.containsOneOf(value, constraint.containsOneOf); | |
} | |
if (constraint.containsAllOf !== undefined) { | |
result = result && ListingFilter.containsAllOf(value, constraint.containsAllOf); | |
} | |
if (constraint.withinArea !== undefined) { | |
result = result && ListingFilter.withinArea(value, constraint.withinArea); | |
} | |
}); | |
return result; | |
}); | |
}, | |
validateConstraints: function(constraints) { | |
let constraintSchema = Joi.array().items(Joi.object().keys({ | |
attribute: Joi.string().required(), | |
minValue: Joi.number(), | |
maxValue: Joi.number(), | |
equalToValue: [Joi.number(), Joi.string(), Joi.boolean()], | |
containsOneOf: Joi.array().items(Joi.string()), | |
containsAllOf: Joi.array().items(Joi.string()), | |
withinArea: Joi.object().keys({ | |
lon: Joi.number(), | |
lat: Joi.number(), | |
radius: Joi.number() | |
}) | |
})); | |
let {error} = Joi.validate(constraints, constraintSchema); | |
if (error) { | |
throw new Error(error); | |
} | |
}, | |
minValue: function(value, constraintValue) { | |
return value >= constraintValue; | |
}, | |
maxValue: function(value, constraintValue) { | |
return value <= constraintValue; | |
}, | |
equalToValue: function(value, constraintValue) { | |
return value === constraintValue; | |
}, | |
containsOneOf: function(array, items) { | |
let intersection = Utility.intersectArrays(array, items); | |
return intersection.length > 0; | |
}, | |
containsAllOf: function(array, items) { | |
let intersection = Utility.intersectArrays(array, items); | |
return intersection.length === array.length; | |
}, | |
withinArea: function(lonLatString, area) { | |
let lonLat = Utility.lonLatStringToCoordinatePair(lonLatString); | |
let withinArea = Utility.isCoordinatePairWithinArea(lonLat, area); | |
return withinArea; | |
} | |
}; | |
/* | |
* Utility functions | |
*/ | |
let Utility = { | |
intersectArrays: function(array1, array2) { | |
return array1.filter(item => { | |
return array2.indexOf(item) !== -1; | |
}); | |
}, | |
/* Converts "POINT (-96.858753 33.116399)" to {lon: -96.858753, lat: 33.116399} */ | |
lonLatStringToCoordinatePair: function(lonLatString) { | |
let pair = lonLatString.substr(7, lonLatString.length - 8).split(' '); | |
return { | |
lon: pair[0], | |
lat: pair[1] | |
}; | |
}, | |
/* areaRadius is in km. Based on https://stackoverflow.com/revisions/24680708/2 */ | |
isCoordinatePairWithinArea: function(coordinatePair, area) { | |
let ky = 40000 / 360; | |
let kx = Math.cos(Math.PI * area.lat / 180.0) * ky; | |
let dx = Math.abs(area.lon - coordinatePair.lon) * kx; | |
let dy = Math.abs(area.lat - coordinatePair.lat) * ky; | |
let distance = Math.sqrt(dx * dx + dy * dy); | |
return distance <= area.radius; | |
} | |
}; | |
/* | |
* Main | |
*/ | |
try { | |
let filtered = ListingFilter.filter(listings, [ | |
{ | |
attribute: 'bedrooms', | |
minValue: 0 | |
}, | |
{ | |
attribute: 'bedrooms', | |
maxValue: 1 | |
}, | |
{ | |
attribute: 'bedrooms', | |
equalToValue: 1 | |
}, | |
{ | |
attribute: 'published', | |
equalToValue: false | |
}, | |
{ | |
attribute: 'pool_type', | |
containsOneOf: ['private'] | |
}, | |
{ | |
attribute: 'pool_type', | |
containsAllOf: ['private', 'public'] | |
}, | |
{ | |
attribute: 'lonlat', | |
withinArea: { | |
lon: -112.021649, | |
lat: 33.606579, | |
radius: 1 | |
} | |
}, | |
]); | |
console.log('filtered', filtered); | |
} | |
catch(error) { | |
console.error(error); | |
process.exit(1); | |
} |
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