refactor(history): use XDG_DATA_STATE as source dir (#209)

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

lua/avante/history.lua

@@ -0,0 +1,49 @@
+local fn, api = vim.fn, vim.api
+local Path = require("plenary.path")
+local Config = require("avante.config")
+
+local M = {}
+
+local H = {}
+
+---@param bufnr integer
+---@return string
+H.filename = function(bufnr)
+  local code_buf_name = api.nvim_buf_get_name(bufnr)
+  -- Replace path separators with double underscores
+  local path_with_separators = fn.substitute(code_buf_name, "/", "__", "g")
+  -- Replace other non-alphanumeric characters with single underscores
+  return fn.substitute(path_with_separators, "[^A-Za-z0-9._]", "_", "g") .. ".json"
+end
+
+---@param bufnr integer
+---@return Path
+M.get = function(bufnr)
+  return Path:new(Config.history.storage_path):joinpath(H.filename(bufnr))
+end
+
+---@param bufnr integer
+M.load = function(bufnr)
+  local history_file = M.get(bufnr)
+  if history_file:exists() then
+    local content = history_file:read()
+    return content ~= nil and vim.json.decode(content) or {}
+  end
+  return {}
+end
+
+---@param bufnr integer
+---@param history table
+M.save = function(bufnr, history)
+  local history_file = M.get(bufnr)
+  history_file:write(vim.json.encode(history), "w")
+end
+
+M.setup = function()
+  local history_dir = Path:new(Config.history.storage_path)
+  if not history_dir:exists() then
+    history_dir:mkdir({ parents = true })
+  end
+end
+
+return M