feat(llm): copilot (closes #68) (#116)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

lua/avante/utils/copilot.lua

@@ -0,0 +1,109 @@
+---This file COPY and MODIFIED based on: https://github.com/CopilotC-Nvim/CopilotChat.nvim/blob/canary/lua/CopilotChat/copilot.lua#L560
+
+---@class avante.utils.copilot
+local M = {}
+
+local version_headers = {
+  ["editor-version"] = "Neovim/" .. vim.version().major .. "." .. vim.version().minor .. "." .. vim.version().patch,
+  ["editor-plugin-version"] = "avante.nvim/0.0.0",
+  ["user-agent"] = "avante.nvim/0.0.0",
+}
+
+---@return string
+M.uuid = function()
+  local template = "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"
+  return (
+    string.gsub(template, "[xy]", function(c)
+      local v = (c == "x") and math.random(0, 0xf) or math.random(8, 0xb)
+      return string.format("%x", v)
+    end)
+  )
+end
+
+---@return string
+M.machine_id = function()
+  local length = 65
+  local hex_chars = "0123456789abcdef"
+  local hex = ""
+  for _ = 1, length do
+    hex = hex .. hex_chars:sub(math.random(1, #hex_chars), math.random(1, #hex_chars))
+  end
+  return hex
+end
+
+---@return string | nil
+local function find_config_path()
+  local config = vim.fn.expand("$XDG_CONFIG_HOME")
+  if config and vim.fn.isdirectory(config) > 0 then
+    return config
+  elseif vim.fn.has("win32") > 0 then
+    config = vim.fn.expand("~/AppData/Local")
+    if vim.fn.isdirectory(config) > 0 then
+      return config
+    end
+  else
+    config = vim.fn.expand("~/.config")
+    if vim.fn.isdirectory(config) > 0 then
+      return config
+    end
+  end
+end
+
+M.cached_token = function()
+  -- loading token from the environment only in GitHub Codespaces
+  local token = os.getenv("GITHUB_TOKEN")
+  local codespaces = os.getenv("CODESPACES")
+  if token and codespaces then
+    return token
+  end
+
+  -- loading token from the file
+  local config_path = find_config_path()
+  if not config_path then
+    return nil
+  end
+
+  -- token can be sometimes in apps.json sometimes in hosts.json
+  local file_paths = {
+    config_path .. "/github-copilot/hosts.json",
+    config_path .. "/github-copilot/apps.json",
+  }
+
+  for _, file_path in ipairs(file_paths) do
+    if vim.fn.filereadable(file_path) == 1 then
+      local userdata = vim.fn.json_decode(vim.fn.readfile(file_path))
+      for key, value in pairs(userdata) do
+        if string.find(key, "github.com") then
+          return value.oauth_token
+        end
+      end
+    end
+  end
+
+  return nil
+end
+
+---@param token string
+---@param sessionid string
+---@param machineid string
+---@return table<string, string>
+M.generate_headers = function(token, sessionid, machineid)
+  local headers = {
+    ["authorization"] = "Bearer " .. token,
+    ["x-request-id"] = M.uuid(),
+    ["vscode-sessionid"] = sessionid,
+    ["vscode-machineid"] = machineid,
+    ["copilot-integration-id"] = "vscode-chat",
+    ["openai-organization"] = "github-copilot",
+    ["openai-intent"] = "conversation-panel",
+    ["content-type"] = "application/json",
+  }
+  for key, value in pairs(version_headers) do
+    headers[key] = value
+  end
+  return headers
+end
+
+M.version_headers = version_headers
+
+return M