defmodule SqliteVec.Ecto.Query do
  @moduledoc """
  Macros for Ecto
  """

  @doc """
  Creates a bit vector
  """
  defmacro vec_bit(vector) do
    quote do
      fragment("vec_bit(?)", type(^unquote(vector).data, :binary))
    end
  end

  @doc """
  Creates an int8 vector
  """
  defmacro vec_int8(vector) do
    quote do
      fragment("vec_int8(?)", type(^unquote(vector).data, :binary))
    end
  end

  @doc """
  Creates a float32 vector
  """
  defmacro vec_f32(vector) do
    quote do
      fragment("vec_f32(?)", type(^unquote(vector).data, :binary))
    end
  end

  @doc """
  Calculates the L2 euclidian distance between vectors a and b. Only valid for float32 or int8 vectors.

  Returns an error under the following conditions:
   -  a or b are invalid vectors
   -  a or b do not share the same vector element types (ex float32 or int8)
   -  a or b are bit vectors. Use vec_distance_hamming() for distance calculations between two bitvectors.
   -  a or b do not have the same length.
  """
  # credo:disable-for-next-line Credo.Check.Readability.FunctionNames
  defmacro vec_distance_L2(a, b) do
    quote do
      fragment("vec_distance_L2(?, ?)", unquote(a), unquote(b))
    end
  end

  @doc """
  Calculates the cosine distance between vectors a and b. Only valid for float32 or int8 vectors.

  Returns an error under the following conditions:
   - a or b are invalid vectors
   - a or b do not share the same vector element types (ex float32 or int8)
   - a or b are bit vectors. Use vec_distance_hamming() for distance calculations between two bitvectors.
   - a or b do not have the same length
  """
  defmacro vec_distance_cosine(a, b) do
    quote do
      fragment("vec_distance_cosine(?, ?)", unquote(a), unquote(b))
    end
  end

  @doc """
  Calculates the hamming distance between two bitvectors a and b. Only valid for bitvectors.

  Returns an error under the following conditions:
   - a or b are not bitvectors
   - a and b do not share the same length
   - Memory cannot be allocated    
  """
  defmacro vec_distance_hamming(a, b) do
    quote do
      fragment("vec_distance_hamming(?, ?)", unquote(a), unquote(b))
    end
  end

  @doc """
  Matches a vector against a virtual table using the `match` operator.
  """
  defmacro vec_match(a, b) do
    quote do
      fragment("? match ?", unquote(a), unquote(b))
    end
  end

  @doc """
  Returns the number of elements in the given vector
  """
  defmacro vec_length(vector) do
    quote do
      fragment("vec_length(?)", unquote(vector))
    end
  end

  @doc """
  Returns the name of the type of `vector` as text
  """
  defmacro vec_type(vector) do
    quote do
      fragment("vec_type(?)", unquote(vector))
    end
  end

  @doc """
  Adds every element in vector a with vector b, returning a new vector c.
  Both vectors must be of the same type and same length.
  Only float32 and int8 vectors are supported.

  An error is raised if either a or b are invalid, or if they are not the same type or same length.
  """
  defmacro vec_add(a, b) do
    quote do
      fragment("vec_add(?, ?)", unquote(a), unquote(b))
    end
  end

  @doc """
  Subtracts every element in vector a with vector b, returning a new vector c.
  Both vectors must be of the same type and same length.
  Only float32 and int8 vectors are supported.

  An error is raised if either a or b are invalid, or if they are not the same type or same length.
  """
  defmacro vec_sub(a, b) do
    quote do
      fragment("vec_sub(?, ?)", unquote(a), unquote(b))
    end
  end

  @doc """
  Performs L2 normalization on the given vector.
  Only float32 vectors are currently supported.

  Returns an error if the input is an invalid vector or not a float32 vector.
  """
  defmacro vec_normalize(vector) do
    quote do
      fragment("vec_normalize(?)", unquote(vector))
    end
  end

  @doc """
  Extract a subset of vector from the start element (inclusive) to the end element (exclusive).

  This is especially useful for Matryoshka embeddings, also known as "adaptive length" embeddings.
  Use with vec_normalize() to get proper results.

  Returns an error in the following conditions:
   - If vector is not a valid vector
   - If start is less than zero or greater than or equal to end
   - If end is greater than the length of vector, or less than or equal to start.
   - If vector is a bitvector, start and end must be divisible by 8.
  """
  defmacro vec_slice(vector, start_index, end_index) do
    quote do
      fragment("vec_slice(?, ?, ?)", unquote(vector), unquote(start_index), unquote(end_index))
    end
  end

  @doc """
  Represents a vector as JSON text.
  The input vector can be a vector BLOB or JSON text.

  Returns an error if vector is an invalid vector, or when memory cannot be allocated.
  """
  defmacro vec_to_json(vector) do
    quote do
      fragment("vec_to_json(?)", unquote(vector))
    end
  end

  @doc """
  Quantize a float32 or int8 vector into a bitvector.
  For every element in the vector, a 1 is assigned to positive numbers and a 0 is assigned to negative numbers.
  These values are then packed into a bit vector.

  Returns an error if vector is invalid, or if vector is not a float32 or int8 vector.
  """
  defmacro vec_quantize_binary(vector) do
    quote do
      fragment("vec_quantize_binary(?)", unquote(vector))
    end
  end
end
