Translate action outcomes

1 files changed, 108 insertions, 0 deletions

diff --git a/lua/clever_f/host_adapter.lua b/lua/clever_f/host_adapter.lua
new file mode 100644
index 0000000..a0eec66
--- /dev/null
+++ b/lua/clever_f/host_adapter.lua
@@ -0,0 +1,108 @@
+local domain = require("clever_f.domain")
+
+local M = {}
+local HostAdapter = {}
+HostAdapter.__index = HostAdapter
+M.HostAdapter = HostAdapter
+
+M.ActionEffect = {
+  NONE = "none",
+  ESCAPE = "escape",
+  ERROR = "error",
+}
+
+local adapter_records = setmetatable({}, { __mode = "k" })
+
+local function fail(message, level)
+  error(message, (level or 1) + 1)
+end
+
+local function current_runtime(options)
+  if type(options) == "table" and options.runtime ~= nil then
+    return options.runtime
+  end
+  if options ~= nil and options ~= HostAdapter then
+    return options
+  end
+  return rawget(_G, "vim")
+end
+
+local function require_runtime(runtime)
+  if type(runtime) ~= "table" or type(runtime.api) ~= "table" then
+    fail("HostAdapter requires the Nvim Lua runtime", 3)
+  end
+  return runtime
+end
+
+function HostAdapter.new(options)
+  if HostAdapter.is(options) then
+    return options
+  end
+  local adapter = setmetatable({}, HostAdapter)
+  adapter_records[adapter] = {
+    runtime = require_runtime(current_runtime(options)),
+  }
+  return adapter
+end
+
+function HostAdapter.is(value)
+  return type(value) == "table" and adapter_records[value] ~= nil
+end
+
+function HostAdapter:runtime()
+  return adapter_records[self].runtime
+end
+
+local function escape_key(runtime)
+  if type(runtime.keycode) == "function" then
+    return runtime.keycode("<Esc>")
+  end
+  if type(runtime.api.nvim_replace_termcodes) == "function" then
+    return runtime.api.nvim_replace_termcodes("<Esc>", true, false, true)
+  end
+  return string.char(27)
+end
+
+function HostAdapter:return_escape()
+  local runtime = self:runtime()
+  if type(runtime.api.nvim_feedkeys) ~= "function" then
+    fail("HostAdapter runtime must provide nvim_feedkeys", 2)
+  end
+  runtime.api.nvim_feedkeys(escape_key(runtime), "n", false)
+end
+
+function HostAdapter:emit_action_error(text)
+  local runtime = self:runtime()
+  if type(runtime.notify) ~= "function" then
+    fail("HostAdapter runtime must provide notify", 2)
+  end
+  local levels = type(runtime.log) == "table" and runtime.log.levels or nil
+  runtime.notify(text, levels and levels.ERROR or nil, { title = "clever-f" })
+end
+
+function HostAdapter:translate_action_outcome(outcome)
+  if not domain.ActionOutcome.is(outcome) then
+    fail("host action translation requires an ActionOutcome", 2)
+  end
+  if outcome.kind == domain.ActionKind.ESCAPE then
+    self:return_escape()
+    return M.ActionEffect.ESCAPE
+  end
+  if outcome.kind == domain.ActionKind.ERROR then
+    self:emit_action_error(outcome.diagnostic)
+    return M.ActionEffect.ERROR
+  end
+  return M.ActionEffect.NONE
+end
+
+function M.new(options)
+  return HostAdapter.new(options)
+end
+
+setmetatable(M, {
+  __call = function(_, options)
+    return HostAdapter.new(options)
+  end,
+})
+
+return M