fix(codecompanion): support editor_context backend for MCP resource vars

lua/mcphub/extensions/codecompanion/variables.lua

@@ -1,82 +1,183 @@
 local M = {}
 local mcphub = require("mcphub")
 
----@param opts MCPHub.Extensions.CodeCompanionConfig
-function M.register(opts)
-    local hub = mcphub.get_hub_instance()
-    if not hub then
+---@param tbl table|nil
+local function cleanup_mcp_items(tbl)
+    if type(tbl) ~= "table" then
         return
     end
 
-    local resources = hub:get_resources()
-    local ok, config = pcall(require, "codecompanion.config")
-    if not ok then
-        return
+    for key, value in pairs(tbl) do
+        if type(value) == "table" then
+            local id = value.id or ""
+            if id:sub(1, 3) == "mcp" then
+                tbl[key] = nil
+            end
+        end
     end
+end
+
+---@param hub MCPHub.Instance
+---@param server_name string
+---@param uri string
+---@return function
+local function make_resource_callback(hub, server_name, uri)
+    return function(self)
+        -- Sync call - blocks UI (can't use async in variables/editor_context yet)
+        local result = hub:access_resource(server_name, uri, {
+            caller = {
+                type = "codecompanion",
+                codecompanion = self,
+                meta = {
+                    is_within_variable = true,
+                },
+            },
+            parse_response = true,
+        })
 
-    local cc_variables = config.interactions.chat.variables
+        if not result then
+            return string.format("Accessing resource failed: %s", uri)
+        end
 
-    -- Remove existing MCP variables
-    for key, value in pairs(cc_variables) do
-        local id = value.id or ""
-        if id:sub(1, 3) == "mcp" then
-            cc_variables[key] = nil
+        -- Handle images
+        if result.images and #result.images > 0 then
+            local helpers = require("codecompanion.interactions.chat.helpers")
+            local chat = self and (self.Chat or self)
+
+            if chat then
+                for _, image in ipairs(result.images) do
+                    local id = string.format("mcp-%s", os.time())
+                    helpers.add_image(chat, {
+                        id = id,
+                        base64 = image.data,
+                        mimetype = image.mimeType,
+                    })
+                end
+            end
         end
+
+        return result.text
     end
+end
+
+---@param resources table
+---@param target table
+---@param hub MCPHub.Instance
+---@return string[]
+local function register_legacy_variables(resources, target, hub)
+    cleanup_mcp_items(target)
 
     local added_resources = {}
-    -- Add current resources as variables
+
     for _, resource in ipairs(resources) do
         local server_name = resource.server_name
         local uri = resource.uri
         local resource_name = resource.name or uri
         local description = resource.description or ""
         description = description:gsub("\n", " ")
         description = resource_name .. " (" .. description .. ")"
+
         local var_id = "mcp:" .. uri
-        cc_variables[var_id] = {
+        target[var_id] = {
             id = "mcp" .. server_name .. uri,
             description = description,
             hide_in_help_window = true,
-            callback = function(self)
-                -- Sync call - blocks UI (can't use async in variables yet)
-                local result = hub:access_resource(server_name, uri, {
-                    caller = {
-                        type = "codecompanion",
-                        codecompanion = self,
-                        meta = {
-                            is_within_variable = true,
-                        },
-                    },
-                    parse_response = true,
-                })
-
-                if not result then
-                    return string.format("Accessing resource failed: %s", uri)
-                end
+            callback = make_resource_callback(hub, server_name, uri),
+        }
 
-                -- Handle images
-                if result.images and #result.images > 0 then
-                    local helpers = require("codecompanion.interactions.chat.helpers")
-                    for _, image in ipairs(result.images) do
-                        local id = string.format("mcp-%s", os.time())
-                        helpers.add_image(self.Chat, {
-                            id = id,
-                            base64 = image.data,
-                            mimetype = image.mimeType,
-                        })
-                    end
-                end
+        table.insert(added_resources, var_id)
+    end
+
+    return added_resources
+end
+
+---@param resources table
+---@param target table
+---@param hub MCPHub.Instance
+---@return string[]
+local function register_editor_context(resources, target, hub)
+    cleanup_mcp_items(target)
 
-                return result.text
-            end,
+    local added_resources = {}
+
+    for _, resource in ipairs(resources) do
+        local server_name = resource.server_name
+        local uri = resource.uri
+        local resource_name = resource.name or uri
+        local description = resource.description or ""
+        description = description:gsub("\n", " ")
+        description = resource_name .. " (" .. description .. ")"
+
+        local var_id = "mcp:" .. uri
+        target[var_id] = {
+            id = "mcp" .. server_name .. uri,
+            description = description,
+            hide_in_help_window = true,
+            callback = make_resource_callback(hub, server_name, uri),
         }
+
         table.insert(added_resources, var_id)
     end
 
-    -- Update syntax highlighting for variables
+    return added_resources
+end
+
+---@param config table
+---@return string|nil, table|nil
+local function get_backend(config)
+    local interactions = config.interactions or {}
+    local chat = interactions.chat or {}
+    local shared = interactions.shared or {}
+
+    if type(chat.variables) == "table" then
+        return "variables", chat.variables
+    end
+
+    if type(shared.editor_context) == "table" then
+        return "editor_context", shared.editor_context
+    end
+
+    if type(chat.editor_context) == "table" then
+        return "editor_context", chat.editor_context
+    end
+
+    return nil, nil
+end
+
+---@param opts MCPHub.Extensions.CodeCompanionConfig
+function M.register(opts)
+    local hub = mcphub.get_hub_instance()
+    if not hub then
+        return
+    end
+
+    local resources = hub:get_resources()
+    local ok, config = pcall(require, "codecompanion.config")
+    if not ok then
+        return
+    end
+
+    local backend, target = get_backend(config)
+    if not backend or not target then
+        vim.notify(
+            "MCPHub: no compatible CodeCompanion resource registration backend found",
+            vim.log.levels.WARN,
+            { title = "MCPHub" }
+        )
+        return
+    end
+
+    local added_resources = {}
+
+    if backend == "variables" then
+        added_resources = register_legacy_variables(resources, target, hub)
+    elseif backend == "editor_context" then
+        added_resources = register_editor_context(resources, target, hub)
+    end
+
     M.update_variable_syntax(added_resources)
 end
+
 -- Setup MCP resources as CodeCompanion variables
 ---@param opts MCPHub.Extensions.CodeCompanionConfig
 function M.setup(opts)