local purge = {}



local util = require("luarocks.util")
local path = require("luarocks.path")
local search = require("luarocks.search")
local vers = require("luarocks.core.vers")
local repo_writer = require("luarocks.repo_writer")
local cfg = require("luarocks.core.cfg")
local remove = require("luarocks.remove")
local queries = require("luarocks.queries")






function purge.add_to_parser(parser)

   local cmd = parser:command("purge", [[
This command removes rocks en masse from a given tree.
By default, it removes all rocks from a tree.

The --tree option is mandatory: luarocks purge does not assume a default tree.]],
   util.see_also()):
   summary("Remove all installed rocks from a tree.")


   cmd:flag("--old-versions", "Keep the highest-numbered version of each " ..
   "rock and remove the other ones. By default it only removes old " ..
   "versions if they are not needed as dependencies. This can be " ..
   "overridden with the flag --force.")
   cmd:flag("--force", "If --old-versions is specified, force removal of " ..
   "previously installed versions if it would break dependencies.")
   cmd:flag("--force-fast", "Like --force, but performs a forced removal " ..
   "without reporting dependency issues.")
end

function purge.command(args)
   local tree = args.tree

   local results = {}
   search.local_manifest_search(results, path.rocks_dir(tree), queries.all())

   local sort = function(a, b) return vers.compare_versions(b, a) end
   if args.old_versions then
      sort = vers.compare_versions
   end

   for pkg, versions in util.sortedpairs(results) do
      for version, _ in util.sortedpairs(versions, sort) do
         if args.old_versions then
            util.printout("Keeping " .. pkg .. " " .. version .. "...")
            local ok, err, warn = remove.remove_other_versions(pkg, version, args.force, args.force_fast)
            if not ok then
               util.printerr(err)
            elseif warn then
               util.printerr(err)
            end
            break
         else
            util.printout("Removing " .. pkg .. " " .. version .. "...")
            local ok, err = repo_writer.delete_version(pkg, version, "none", true)
            if not ok then
               util.printerr(err)
            end
         end
      end
   end
   return repo_writer.refresh_manifest(cfg.rocks_dir)
end

purge.needs_lock = function() return true end

return purge