refactor(copilotchat-nvim): improve picker selection logic and error handling

lua/astrocommunity/editing-support/copilotchat-nvim/init.lua

@@ -67,17 +67,66 @@ return {
           desc = "Load Chat",
         }
 
+        -- Determine the currently active picker
+        local function get_active_picker()
+          -- Check CopilotChat compatibel pickers
+          -- this is also a mapping between picker module names and their
+          -- counterparts in the CopilotChat integrations
+          -- snacks.picker is tricky because we can't just assume that if snacks.nvim is
+          -- installed, it's being used as the picker, too
+          if
+            require("astrocore").is_available "snacks.nvim"
+            and (function()
+              local snacks = require "snacks.picker"
+              return snacks.config and snacks.config.ui_select
+            end)()
+          then
+            return "snacks"
+          elseif require("astrocore").is_available "fzf-lua" then
+            return "fzflua"
+          elseif require("astrocore").is_available "telescope.nvim" then
+            return "telescope"
+          end
+
+          -- Default fallback
+          return nil
+        end
+
         -- Helper function to create mappings
         local function create_mapping(action_type, selection_type)
           return function()
-            local fzf_ok = pcall(require, "fzf-lua")
-            local snacks_ok = pcall(require, "snacks")
+            local actions = require "CopilotChat.actions"
+            local items = actions[action_type] { selection = require("CopilotChat.select")[selection_type] }
+            if not items then
+              vim.notify("No " .. action_type:gsub("_", " ") .. " found for the current selection", vim.log.levels.WARN)
+              return
+            end
+
+            -- Determine the active picker
+            local picker = get_active_picker()
+            if not picker then
+              vim.notify(
+                "No valid picker is enabled. Please enable one of telescope, fzf-lua, or snacks.",
+                vim.log.levels.ERROR
+              )
+              return
+            end
+
+            -- Attempt to load the picker module
+            local ok, picker_module = pcall(require, "CopilotChat.integrations." .. picker)
+            if not ok then
+              vim.notify(
+                ("Integration module '%s' for picker '%s' is not available. Ensure it is installed and enabled."):format(
+                  picker,
+                  picker
+                ),
+                vim.log.levels.WARN
+              )
+              return
+            end
 
-            require("CopilotChat.integrations." .. (fzf_ok and "fzflua" or snacks_ok and "snacks" or "telescope")).pick(
-              require("CopilotChat.actions")[action_type] {
-                selection = require("CopilotChat.select")[selection_type],
-              }
-            )
+            -- Use the selected picker module
+            picker_module.pick(items)
           end
         end