---@class jjannotate.Cache
---@field wins table<integer, jjannotate.Window?> win id -> Window
---@field win_by_revision table<string, table<string, table<string, jjannotate.Window?>>> root -> path -> change id -> Window
local Cache = {}
Cache.__index = Cache

---@return jjannotate.Cache
function Cache.new()
  ---@type jjannotate.Cache
  local c = {
    wins = {},
    win_by_revision = {},
  }
  return setmetatable(c, Cache)
end

---@param revision jjannotate.RevisionRef
---@return jjannotate.Window?
function Cache:get_by_revision(revision)
  return self.win_by_revision[revision.repo]
    and self.win_by_revision[revision.repo][revision.path]
    and self.win_by_revision[revision.repo][revision.path][revision.change_id]
end

---@param win_id integer
---@return jjannotate.Window?
function Cache:get_by_id(win_id) return self.wins[win_id] end

---@param revision jjannotate.RevisionRef
---@param w jjannotate.Window
function Cache:set_win(revision, w)
  self.wins[w.id] = w
  if not self.win_by_revision[revision.repo] then self.win_by_revision[revision.repo] = {} end
  if not self.win_by_revision[revision.repo][revision.path] then
    self.win_by_revision[revision.repo][revision.path] = {}
  end
  self.win_by_revision[revision.repo][revision.path][revision.change_id] = w
end

---@param win_id integer
---@return boolean
function Cache:del_win(win_id)
  local w = self:get_by_id(win_id)
  if not w then return false end
  self.wins[win_id] = nil

  local repo, path, change_id = w.revision.repo, w.revision.path, w.revision.change_id
  local by_path = self.win_by_revision[repo][path]
  by_path[change_id] = nil
  if vim.tbl_isempty(by_path) then
    self.win_by_revision[repo][path] = nil
    if vim.tbl_isempty(self.win_by_revision[repo]) then self.win_by_revision[repo] = nil end
  end

  return true
end

return Cache.new()