feat(nvim): use codecompanion extension API. (#99)

* feat(nvim): use codecompanion extension API.

* add default options for extension, as well as slash command.

* add duplicate-detection and logging.

Author: Davidyz

lua/codecompanion/_extensions/vectorcode/init.lua

@@ -0,0 +1,74 @@
+---@module "codecompanion"
+
+---@class VectorCode.CodeCompanion.ExtensionOpts
+---@field add_tools boolean|string|nil
+---@field tool_opts VectorCode.CodeCompanion.ToolOpts
+---@field add_slash_command boolean
+
+local vc_config = require("vectorcode.config")
+local logger = vc_config.logger
+
+---@type CodeCompanion.Extension
+local M = {
+  ---@param opts VectorCode.CodeCompanion.ExtensionOpts
+  setup = vc_config.check_cli_wrap(function(opts)
+    opts = vim.tbl_deep_extend(
+      "force",
+      { add_tool = true, add_slash_command = false },
+      opts or {}
+    )
+    logger.info("Received codecompanion extension opts:\n", opts)
+    local cc_config = require("codecompanion.config").config
+    local cc_integration = require("vectorcode.integrations").codecompanion.chat
+    if opts.add_tool then
+      local tool_name = "vectorcode"
+      if type(opts.add_tool) == "string" then
+        tool_name = tostring(opts.add_tool)
+      end
+      if cc_config.strategies.chat.tools[tool_name] ~= nil then
+        vim.notify(
+          "There's an existing tool named `vectorcode`. Please either remove it or rename it.",
+          vim.log.levels.ERROR,
+          vc_config.notify_opts
+        )
+        logger.warn(
+          string.format(
+            "Not creating a tool because there is an existing tool named %s.",
+            tool_name
+          )
+        )
+      else
+        cc_config.strategies.chat.tools[tool_name] = {
+          description = "Run VectorCode to retrieve the project context.",
+          callback = cc_integration.make_tool(opts.tool_opts),
+        }
+        logger.info(string.format("%s tool has been created.", tool_name))
+      end
+    end
+    if opts.add_slash_command then
+      local command_name = "vectorcode"
+      if type(opts.add_slash_command) == "string" then
+        command_name = tostring(opts.add_slash_command)
+      end
+      if cc_config.strategies.chat.slash_commands[command_name] ~= nil then
+        vim.notify(
+          "There's an existing slash command named `vectorcode`. Please either remove it or rename it.",
+          vim.log.levels.ERROR,
+          vc_config.notify_opts
+        )
+        logger.warn(
+          string.format(
+            "Not creating a command because there is an existing slash command named %s.",
+            command_name
+          )
+        )
+      else
+        cc_config.strategies.chat.slash_commands[command_name] =
+          cc_integration.make_slash_command()
+        logger.info(string.format("%s command has been created.", command_name))
+      end
+    end
+  end),
+}
+
+return M