feat(context): context bar (#69)

This PR is adding a context bar to manage/view context being sent by the plugin.

You can now manage the context via the completion menu with the `#` trigger.

Author: sudo-tee

README.md

@@ -132,6 +132,8 @@ require('opencode').setup({
       ['~'] = { 'mention_file', mode = 'i' }, -- Pick a file and add to context. See File Mentions section
       ['@'] = { 'mention', mode = 'i' }, -- Insert mention (file/agent)
       ['/'] = { 'slash_commands', mode = 'i' }, -- Pick a command to run in the input window
+      ['#'] = { 'context_items', mode = 'i' }, -- Manage context items (current file, selection, diagnostics, mentioned files)
+      ['<C-i>'] = { 'focus_input', mode = { 'n', 'i' } }, -- Focus on input window and enter insert mode at the end of the input from the output window
       ['<tab>'] = { 'toggle_pane', mode = { 'n', 'i' } }, -- Toggle between input and output panes
       ['<up>'] = { 'prev_prompt_history', mode = { 'n', 'i' } }, -- Navigate to previous prompt in history
       ['<down>'] = { 'next_prompt_history', mode = { 'n', 'i' } }, -- Navigate to next prompt in history
@@ -425,6 +427,34 @@ The following editor context is automatically captured and included in your conv
 You can reference files in your project directly in your conversations with Opencode. This is useful when you want to ask about or provide context about specific files. Type `@` in the input window to trigger the file picker.
 Supported pickers include [`fzf-lua`](https://github.com/ibhagwan/fzf-lua), [`telescope`](https://github.com/nvim-telescope/telescope.nvim), [`mini.pick`](https://github.com/echasnovski/mini.nvim/blob/main/readmes/mini-pick.md), [`snacks`](https://github.com/folke/snacks.nvim/blob/main/docs/picker.md)
 
+### Context bar
+
+You can quiclkly see the current context items in the context bar at the top of the input window:
+
+<div align="center">
+  <img src="https://i.imgur.com/vGgu6br.png" alt="Opencode.nvim context bar" width="90%" />
+</div>
+
+### Context Items Completion
+
+You can quickly reference available context items by typing `#` in the input window. This will show a completion menu with all available context items:
+
+- **Current File** - The currently focused file in the editor
+- **Selection** - Currently selected text in visual mode
+- **Diagnostics** - LSP diagnostics from the current file
+- **Cursor Data** - Current cursor position and line content
+- **[filename]** - Files that have been mentioned in the conversation
+- **Agents** - Available agents to switch to
+- **Selections** - Previously made selections in visual mode
+
+Context items that are not currently available will be shown as disabled in the completion menu.
+
+You should also see the list of files agents and selections in the menu, selecting them in the menu will remove them from the context.
+
+<div align="center">
+  <img src="https://i.imgur.com/UqQKW33.png" alt="Opencode.nvim context items completion" width="90%" />
+</div>
+
 ## 🔄 Agents
 
 Opencode provides two built-in agents and supports custom ones:

lua/opencode/api.lua

@@ -299,6 +299,13 @@ function M.mention()
   require('opencode.ui.completion').trigger_completion(char)()
 end
 
+function M.context_items()
+  local config = require('opencode.config')
+  local char = config.get_key_for_function('input_window', 'context_items')
+  ui.focus_input({ restore_position = true, start_insert = true })
+  require('opencode.ui.completion').trigger_completion(char)()
+end
+
 function M.slash_commands()
   local config = require('opencode.config')
   local char = config.get_key_for_function('input_window', 'slash_commands')

lua/opencode/config.lua

@@ -56,6 +56,7 @@ M.defaults = {
       ['~'] = { 'mention_file', mode = 'i' },
       ['@'] = { 'mention', mode = 'i' },
       ['/'] = { 'slash_commands', mode = 'i' },
+      ['#'] = { 'context_items', mode = 'i' },
       ['<tab>'] = { 'toggle_pane', mode = { 'n', 'i' } },
       ['<up>'] = { 'prev_prompt_history', mode = { 'n', 'i' } },
       ['<down>'] = { 'next_prompt_history', mode = { 'n', 'i' } },
@@ -148,6 +149,7 @@ M.defaults = {
       enabled = false,
     },
     diagnostics = {
+      enabled = true,
       info = false,
       warning = true,
       error = true,
@@ -163,6 +165,9 @@ M.defaults = {
     selection = {
       enabled = true,
     },
+    agents = {
+      enabled = true,
+    },
   },
   debug = {
     enabled = false,
@@ -300,4 +305,4 @@ return setmetatable(M, {
   __tostring = function(_)
     return vim.inspect(M.values)
   end,
-})
+}) --[[@as OpencodeConfig &  OpencodeConfigModule]]