req_cassette

defmodule ReqCassette.Template.Presets do
  @moduledoc """
  Built-in pattern presets for common API providers.

  Presets provide pre-configured regex patterns for dynamic values
  commonly found in specific API responses. This is especially useful
  for LLM APIs where message IDs, tool use IDs, and request IDs change
  with every call.

  ## Available Presets

  - `:anthropic` - Anthropic Claude API patterns (`msg_*`, `toolu_*`, `req_*`)
  - `:openai` - OpenAI API patterns (`chatcmpl-*`, `call_*`)
  - `:llm` - All LLM provider patterns combined
  - `:common` - Common patterns (UUIDs, ISO timestamps)

  ## Usage

  Presets can be used alone or combined with custom patterns:

      # Use preset only
      template: [preset: :anthropic]

      # Preset with additional patterns (explicit patterns override preset)
      template: [preset: :anthropic, patterns: [order_id: ~r/ORD-\\d+/]]

      # Combined LLM preset for multi-provider support
      template: [preset: :llm]

  ## Pattern Details

  ### Anthropic Patterns

  | Pattern | Regex | Example |
  |---------|-------|---------|
  | `msg_id` | `msg_[a-zA-Z0-9]+` | `msg_01XzW7o3s58J6KauMpLBFtEf` |
  | `toolu_id` | `toolu_[a-zA-Z0-9]+` | `toolu_01K6u2Q9D6W7heeVvKAcLcAJ` |
  | `anthropic_request_id` | `req_[a-zA-Z0-9]+` | `req_01234abcdef` |

  ### OpenAI Patterns

  | Pattern | Regex | Example |
  |---------|-------|---------|
  | `chatcmpl_id` | `chatcmpl-[a-zA-Z0-9]+` | `chatcmpl-abc123def456` |
  | `call_id` | `call_[a-zA-Z0-9]+` | `call_abc123` |

  ### Common Patterns

  | Pattern | Regex | Example |
  |---------|-------|---------|
  | `uuid` | UUID v4 format | `550e8400-e29b-41d4-a716-446655440000` |
  | `iso_timestamp` | ISO 8601 datetime | `2025-01-15T10:30:00Z` |
  """

  @anthropic_patterns [
    msg_id: ~r/msg_[a-zA-Z0-9]+/,
    toolu_id: ~r/toolu_[a-zA-Z0-9]+/,
    anthropic_request_id: ~r/req_[a-zA-Z0-9]+/
  ]

  @openai_patterns [
    chatcmpl_id: ~r/chatcmpl-[a-zA-Z0-9]+/,
    call_id: ~r/call_[a-zA-Z0-9]+/
  ]

  @common_patterns [
    uuid: ~r/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/i,
    iso_timestamp: ~r/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?(Z|[+-]\d{2}:\d{2})?/
  ]

  @doc """
  Returns patterns for the given preset name.

  ## Parameters

  - `preset_name` - One of `:anthropic`, `:openai`, `:llm`, or `:common`

  ## Returns

  - `{:ok, patterns}` - A keyword list of `{name, regex}` pairs
  - `{:error, {:unknown_preset, name}}` - If the preset is not recognized

  ## Examples

      iex> {:ok, patterns} = ReqCassette.Template.Presets.get(:anthropic)
      iex> Keyword.keys(patterns)
      [:msg_id, :toolu_id, :anthropic_request_id]

      iex> ReqCassette.Template.Presets.get(:unknown)
      {:error, {:unknown_preset, :unknown}}
  """
  @spec get(atom()) :: {:ok, keyword(Regex.t())} | {:error, {:unknown_preset, atom()}}
  def get(:anthropic), do: {:ok, @anthropic_patterns}
  def get(:openai), do: {:ok, @openai_patterns}
  def get(:common), do: {:ok, @common_patterns}
  def get(:llm), do: {:ok, @anthropic_patterns ++ @openai_patterns}
  def get(name), do: {:error, {:unknown_preset, name}}

  @doc """
  Lists all available preset names.

  ## Examples

      iex> ReqCassette.Template.Presets.available()
      [:anthropic, :openai, :llm, :common]
  """
  @spec available() :: [atom()]
  def available, do: [:anthropic, :openai, :llm, :common]

  @doc """
  Returns patterns for the given preset name, raising on error.

  ## Parameters

  - `preset_name` - One of `:anthropic`, `:openai`, `:llm`, or `:common`

  ## Returns

  A keyword list of `{name, regex}` pairs.

  ## Raises

  `ArgumentError` if the preset is not recognized.

  ## Examples

      iex> patterns = ReqCassette.Template.Presets.get!(:anthropic)
      iex> Keyword.keys(patterns)
      [:msg_id, :toolu_id, :anthropic_request_id]
  """
  @spec get!(atom()) :: keyword(Regex.t())
  def get!(preset_name) do
    case get(preset_name) do
      {:ok, patterns} ->
        patterns

      {:error, {:unknown_preset, name}} ->
        raise ArgumentError, """
        Unknown template preset: #{inspect(name)}

        Available presets: #{inspect(available())}

        Example usage:
          template: [preset: :anthropic]
          template: [preset: :llm]
        """
    end
  end
end