1 files changed, 53 insertions, 0 deletions
diff --git a/lua/blink/cmp/sources/cmdline/help.lua b/lua/blink/cmp/sources/cmdline/help.lua
new file mode 100644
index 0000000..bae4988
--- /dev/null
+++ b/lua/blink/cmp/sources/cmdline/help.lua
@@ -0,0 +1,53 @@
+local async = require('blink.cmp.lib.async')
+
+local help = {}
+
+--- Processes a help file and returns a list of tags asynchronously
+--- @param file string
+--- @return blink.cmp.Task
+--- TODO: rewrite using async lib, shared as a library in lib/fs.lua
+local function read_tags_from_file(file)
+  return async.task.new(function(resolve)
+    vim.uv.fs_open(file, 'r', 438, function(err, fd)
+      if err or fd == nil then return resolve({}) end
+
+      -- Read file content
+      vim.uv.fs_fstat(fd, function(stat_err, stat)
+        if stat_err or stat == nil then
+          vim.uv.fs_close(fd)
+          return resolve({})
+        end
+
+        vim.uv.fs_read(fd, stat.size, 0, function(read_err, data)
+          vim.uv.fs_close(fd)
+
+          if read_err or data == nil then return resolve({}) end
+
+          -- Process the file content
+          local tags = {}
+          for line in data:gmatch('[^\r\n]+') do
+            local tag = line:match('^([^\t]+)')
+            if tag then table.insert(tags, tag) end
+          end
+
+          resolve(tags)
+        end)
+      end)
+    end)
+  end)
+end
+
+--- @param arg_prefix string
+function help.get_completions(arg_prefix)
+  local help_files = vim.api.nvim_get_runtime_file('doc/tags', true)
+
+  return async.task
+    .await_all(vim.tbl_map(read_tags_from_file, help_files))
+    :map(function(tags_arrs) return require('blink.cmp.lib.utils').flatten(tags_arrs) end)
+    :map(function(tags)
+      -- TODO: remove after adding support for fuzzy matching on custom range
+      return vim.tbl_filter(function(tag) return vim.startswith(tag, arg_prefix) end, tags)
+    end)
+end
+
+return help