def deps do
  [
    {:geo_postgis, "~> 3.4"}
  ]
end

# When a binary is passed to `Geo.PostGIS.Geometry.cast/1` implementation of
# `Ecto.Type.cast/1`, it is assumed to be a GeoJSON string. When this happens,
# geo_postgis will use Poison, by default, to convert the binary to a map and
# then convert that map to one of the Geo structs. If in these cases you would
# like to use a different JSON parser, you can set the config below.

# config.exs
config :geo_postgis,
  json_library: Jason # If you want to set your JSON module

Postgrex.Types.define(MyApp.PostgresTypes, [Geo.PostGIS.Extension], [])

opts = [hostname: "localhost", username: "postgres", database: "geo_postgrex_test", types: MyApp.PostgresTypes ]
[hostname: "localhost", username: "postgres", database: "geo_postgrex_test", types: MyApp.PostgresTypes]

{:ok, pid} = Postgrex.Connection.start_link(opts)
{:ok, #PID<0.115.0>}

geo = %Geo.Point{coordinates: {30, -90}, srid: 4326}
%Geo.Point{coordinates: {30, -90}, srid: 4326}

{:ok, _} = Postgrex.Connection.query(pid, "CREATE TABLE point_test (id int, geom geometry(Point, 4326))")
{:ok, %Postgrex.Result{columns: nil, command: :create_table, num_rows: 0, rows: nil}}

{:ok, _} = Postgrex.Connection.query(pid, "INSERT INTO point_test VALUES ($1, $2)", [42, geo])
{:ok, %Postgrex.Result{columns: nil, command: :insert, num_rows: 1, rows: nil}}

Postgrex.Connection.query(pid, "SELECT * FROM point_test")
{:ok, %Postgrex.Result{columns: ["id", "geom"], command: :select, num_rows: 1,
rows: [{42, %Geo.Point{coordinates: {30.0, -90.0}, srid: 4326 }}]}}

#If using with Ecto, you may want something like thing instead
Postgrex.Types.define(MyApp.PostgresTypes,
              [Geo.PostGIS.Extension] ++ Ecto.Adapters.Postgres.extensions(),
              json: Jason)

#Add extensions to your repo config
config :thanks, Repo,
  database: "geo_postgrex_test",
  username: "postgres",
  password: "postgres",
  hostname: "localhost",
  adapter: Ecto.Adapters.Postgres,
  types: MyApp.PostgresTypes


#Create a schema
defmodule Test do
  use Ecto.Schema

  schema "test" do
    field :name,           :string
    field :geom,           Geo.PostGIS.Geometry
  end
end

#Geometry or Geography columns can be created in migrations too
defmodule Repo.Migrations.Init do
  use Ecto.Migration

  def up do
    create table(:test) do
      add :name,     :string
      add :geom,     :geometry
    end
  end

  def down do
    drop table(:test)
  end
end

defmodule Repo.Migrations.AdvancedInit do
  use Ecto.Migration

  def up do
    create table(:test) do
      add :name,     :string
    end
    # Add a field `lng_lat_point` with type `geometry(Point,4326)`.
    # This can store a "standard GPS" (epsg4326) coordinate pair {longitude,latitude}.
    execute("SELECT AddGeometryColumn ('test','lng_lat_point',4326,'POINT',2);")

    # Once a GIS data table exceeds a few thousand rows, you will want to build an index to speed up spatial searches of the data
    # Syntax - CREATE INDEX [indexname] ON [tablename] USING GIST ( [geometryfield] );
    execute("CREATE INDEX test_geom_idx ON test USING GIST (lng_lat_point);")
  end

  def down do
    drop table(:test)
  end
end

defmodule MyApp.Repo.Migrations.EnablePostgis do
  use Ecto.Migration

  def up do
    execute "CREATE EXTENSION IF NOT EXISTS postgis"
  end

  def down do
    execute "DROP EXTENSION IF EXISTS postgis"
  end
end

defmodule Example do
  import Ecto.Query
  import Geo.PostGIS

  def example_query(geom) do
    query = from location in Location, limit: 5, select: st_distance(location.geom, ^geom)
    query
    |> Repo.one
  end
end