class Location

    DB = PG.connect({:host => "localhost", :port => 5432, :dbname => 'contacts'})

    def self.all
        results = DB.exec(
            <<-SQL
                SELECT
                    locations.*,
                    people.id AS person_id,
                    people.name,
                    people.age
                FROM locations
                LEFT JOIN people
                ON locations.id = people.home_id
            SQL
        )
        locations = []
        last_location_id = nil
        results.each do |result|
            if result["id"] != last_location_id
                locations.push(
                    {
                        "id" => result["id"].to_i,
                        "street" => result["street"],
                        "city" => result["city"],
                        "state" => result["state"],
                        "inhabitants" => []
                    }
                )
                last_location_id = result["id"]
            end
            if result["person_id"]
                new_person = {
                    "id" => result["person_id"].to_i,
                    "name" => result["name"],
                    "age" => result["age"].to_i,
                }
                locations.last["inhabitants"].push(new_person)
            end
        end
        return locations
    end

    def self.find(id)
        results = DB.exec(
            <<-SQL
                SELECT
                    locations.*,
                    people.id AS person_id,
                    people.name,
                    people.age
                FROM locations
                LEFT JOIN people
                ON locations.id = people.home_id
                WHERE locations.id=#{id};
            SQL
        )
        inhabitants = []
        results.each do |result|
            if result["person_id"]
                inhabitants.push({
                    "id" => result["person_id"].to_i,
                    "name" => result["name"],
                    "age" => result["age"].to_i,
                })
            end
        end

        return {
            "id" => results.first["id"].to_i,
            "street" => results.first["street"],
            "city" => results.first["city"],
            "state" => results.first["state"],
            "inhabitants" => inhabitants
        }
    end

    def self.create(opts={})
        results = DB.exec(
            <<-SQL
                INSERT INTO locations (street, city, state)
                VALUES ( '#{opts["street"]}', '#{opts["city"]}', '#{opts["state"]}' )
                RETURNING id, street, city, state;
            SQL
        )
        return {
            "id" => results.first["id"],
            "street" => results.first["street"],
            "city" => results.first["city"],
            "state" => results.first["state"]
        }
    end

    def self.delete(id)
        results = DB.exec("DELETE FROM locations WHERE id=#{id};")
        return { deleted: true }
    end

    def self.update(id, opts={})
        results = DB.exec(
            <<-SQL
                UPDATE locations
                SET street='#{opts["street"]}', city='#{opts["city"]}', state='#{opts["state"]}'
                WHERE id=#{id}
                RETURNING id, street, city, state;
            SQL
        )
        return {
            "id" => results.first["id"],
            "street" => results.first["street"],
            "city" => results.first["city"],
            "state" => results.first["state"]
        }
    end
end