--- Functions for managing the repository on disk.
module("luarocks.repos", package.seeall)

local fs = require("luarocks.fs")
local path = require("luarocks.path")
local cfg = require("luarocks.cfg")
local util = require("luarocks.util")
local dir = require("luarocks.dir")
local manif = require("luarocks.manif")
local deps = require("luarocks.deps")

--- Get all installed versions of a package.
-- @param name string: a package name.
-- @return table or nil: An array of strings listing installed
-- versions of a package, or nil if none is available.
local function get_installed_versions(name)
   assert(type(name) == "string")
   
   local dirs = fs.list_dir(path.versions_dir(name))
   return (dirs and #dirs > 0) and dirs or nil
end

--- Check if a package exists in a local repository.
-- Version numbers are compared as exact string comparison.
-- @param name string: name of package
-- @param version string: package version in string format
-- @return boolean: true if a package is installed,
-- false otherwise.
function is_installed(name, version)
   assert(type(name) == "string")
   assert(type(version) == "string")
      
   return fs.is_dir(path.install_dir(name, version))
end

local function recurse_rock_manifest_tree(file_tree, action) 
   assert(type(file_tree) == "table")
   assert(type(action) == "function")
   local function do_recurse_rock_manifest_tree(tree, parent_path, parent_module)
      
      for file, sub in pairs(tree) do
         if type(sub) == "table" then
            local ok, err = do_recurse_rock_manifest_tree(sub, parent_path..file.."/", parent_module..file..".")
            if not ok then return nil, err end
         else
            local ok, err = action(parent_path, parent_module, file)
            if not ok then return nil, err end
         end
      end
      return true
   end
   return do_recurse_rock_manifest_tree(file_tree, "", "")
end

local function store_package_data(result, name, file_tree)
   if not file_tree then return end
   return recurse_rock_manifest_tree(file_tree, 
      function(parent_path, parent_module, file)
         local pathname = parent_path..file
         result[path.path_to_module(pathname)] = pathname
         return true
      end
   )
end

--- Obtain a list of modules within an installed package.
-- @param package string: The package name; for example "luasocket"
-- @param version string: The exact version number including revision;
-- for example "2.0.1-1".
-- @return table: A table of modules where keys are module identifiers
-- in "foo.bar" format and values are pathnames in architecture-dependent
-- "foo/bar.so" format. If no modules are found or if package or version
-- are invalid, an empty table is returned.
function package_modules(package, version)
   assert(type(package) == "string")
   assert(type(version) == "string")

   local result = {}
   local rock_manifest = manif.load_rock_manifest(package, version)
   store_package_data(result, package, rock_manifest.lib)
   store_package_data(result, package, rock_manifest.lua)
   return result
end

--- Obtain a list of command-line scripts within an installed package.
-- @param package string: The package name; for example "luasocket"
-- @param version string: The exact version number including revision;
-- for example "2.0.1-1".
-- @return table: A table of items where keys are command names
-- as strings and values are pathnames in architecture-dependent
-- ".../bin/foo" format. If no modules are found or if package or version
-- are invalid, an empty table is returned.
function package_commands(package, version)
   assert(type(package) == "string")
   assert(type(version) == "string")

   local result = {}
   local rock_manifest = manif.load_rock_manifest(package, version)
   store_package_data(result, package, rock_manifest.bin)
   return result
end


--- Check if a rock contains binary executables.
-- @param name string: name of an installed rock
-- @param version string: version of an installed rock
-- @return boolean: returns true if rock contains platform-specific
-- binary executables, or false if it is a pure-Lua rock.
function has_binaries(name, version)
   assert(type(name) == "string")
   assert(type(version) == "string")

   local rock_manifest = manif.load_rock_manifest(name, version)
   if rock_manifest.bin then
      for name, md5 in pairs(rock_manifest.bin) do
         -- TODO verify that it is the same file. If it isn't, find the actual command.
         if fs.is_actual_binary(dir.path(cfg.deploy_bin_dir, name)) then
            return true
         end
      end
   end
   return false
end

function run_hook(rockspec, hook_name)
   assert(type(rockspec) == "table")
   assert(type(hook_name) == "string")

   local hooks = rockspec.hooks
   if not hooks then
      return true
   end
   if not hooks.substituted_variables then
      util.variable_substitutions(hooks, rockspec.variables)
      hooks.substituted_variables = true
   end
   local hook = hooks[hook_name]
   if hook then
      util.printout(hook)
      if not fs.execute(hook) then
         return nil, "Failed running "..hook_name.." hook."
      end
   end
   return true
end

local function install_binary(source, target)
   assert(type(source) == "string")
   assert(type(target) == "string")

   local match = source:match("%.lua$")
   local file, ok, err
   if not match then
      file = io.open(source)
   end
   if match or (file and file:read():match("^#!.*lua.*")) then
      ok, err = fs.wrap_script(source, target)
   else
      ok, err = fs.copy_binary(source, target)
   end
   if file then file:close() end
   return ok, err
end

local function resolve_conflict(target, deploy_dir, name, version)
   local cname, cversion = manif.find_current_provider(target)
   if not cname then
      return nil, cversion
   end
   if name ~= cname or deps.compare_versions(version, cversion) then
      local versioned = path.versioned_name(target, deploy_dir, cname, cversion)
      fs.make_dir(dir.dir_name(versioned))
      fs.move(target, versioned)
      return target
   else
      return path.versioned_name(target, deploy_dir, name, version)
   end
end

function should_wrap_bin_scripts(rockspec)
   assert(type(rockspec) == "table")

   if cfg.wrap_bin_scripts ~= nil then
      return cfg.wrap_bin_scripts
   end
   if rockspec.deploy and rockspec.deploy.wrap_bin_scripts == false then
      return false
   end
   return true
end

function deploy_files(name, version, wrap_bin_scripts)
   assert(type(name) == "string")
   assert(type(version) == "string")
   assert(type(wrap_bin_scripts) == "boolean")

   local function deploy_file_tree(file_tree, source_dir, deploy_dir, move_fn)
      if not move_fn then
         move_fn = fs.move
      end
      return recurse_rock_manifest_tree(file_tree, 
         function(parent_path, parent_module, file)
            local source = dir.path(source_dir, parent_path, file)
            local target = dir.path(deploy_dir, parent_path, file)
            local ok, err
            if fs.exists(target) then
               local new_target, err = resolve_conflict(target, deploy_dir, name, version)
               if err == "untracked" then
                  fs.delete(target)
               elseif err then
                  return nil, err.." Cannot install new version."
               else
                  target = new_target
               end
            end
            fs.make_dir(dir.dir_name(target))
            ok, err = move_fn(source, target)
            fs.remove_dir_tree_if_empty(dir.dir_name(source))
            if not ok then return nil, err end
            return true
         end
      )
   end

   local rock_manifest = manif.load_rock_manifest(name, version)
   
   local ok, err = true
   if rock_manifest.bin then
      local move_bin_fn = wrap_bin_scripts and install_binary or fs.copy_binary
      ok, err = deploy_file_tree(rock_manifest.bin, path.bin_dir(name, version), cfg.deploy_bin_dir, move_bin_fn)
   end
   if ok and rock_manifest.lua then
      ok, err = deploy_file_tree(rock_manifest.lua, path.lua_dir(name, version), cfg.deploy_lua_dir)
   end
   if ok and rock_manifest.lib then
      ok, err = deploy_file_tree(rock_manifest.lib, path.lib_dir(name, version), cfg.deploy_lib_dir)
   end
   return ok, err
end

--- Delete a package from the local repository.
-- Version numbers are compared as exact string comparison.
-- @param name string: name of package
-- @param version string: package version in string format
-- @param quick boolean: do not try to fix the versioned name
-- of another version that provides the same module that
-- was deleted. This is used during 'purge', as every module
-- will be eventually deleted.
function delete_version(name, version, quick)
   assert(type(name) == "string")
   assert(type(version) == "string")

   local function delete_deployed_file_tree(file_tree, deploy_dir)
      return recurse_rock_manifest_tree(file_tree, 
         function(parent_path, parent_module, file)
            local target = dir.path(deploy_dir, parent_path, file)
            local versioned = path.versioned_name(target, deploy_dir, name, version)
            if fs.exists(versioned) then
               local ok = fs.delete(versioned)
               fs.remove_dir_tree_if_empty(dir.dir_name(versioned))
               if not ok then return nil, "Failed deleting "..versioned end
            else
               local ok = fs.delete(target)
               if not quick then
                  local next_name, next_version = manif.find_next_provider(target)
                  if next_name then
                     local versioned = path.versioned_name(target, deploy_dir, next_name, next_version)
                     fs.move(versioned, target)
                     fs.remove_dir_tree_if_empty(dir.dir_name(versioned))
                  end
               end
               fs.remove_dir_tree_if_empty(dir.dir_name(target))
               if not ok then return nil, "Failed deleting "..target end
            end
            return true
         end
      )
   end

   local rock_manifest = manif.load_rock_manifest(name, version)
   if not rock_manifest then
      return nil, "rock_manifest file not found for "..name.." "..version.." - not a LuaRocks 2 tree?"
   end
   
   local ok, err = true
   if rock_manifest.bin then
      ok, err = delete_deployed_file_tree(rock_manifest.bin, cfg.deploy_bin_dir)
   end
   if ok and rock_manifest.lua then
      ok, err = delete_deployed_file_tree(rock_manifest.lua, cfg.deploy_lua_dir)
   end
   if ok and rock_manifest.lib then
      ok, err = delete_deployed_file_tree(rock_manifest.lib, cfg.deploy_lib_dir)
   end
   if err then return nil, err end

   fs.delete(path.install_dir(name, version))
   if not get_installed_versions(name) then
      fs.delete(dir.path(cfg.rocks_dir, name))
   end
   return true
end