package.path = Helix.Core.Server.GetArchDirFileName( "?.lua" )
local inspect = require( "inspect" )

local utils = require  "ExtUtils"
local initDone = false
local p4

function init()
  if not initDone then
    utils.init()
  end
end

function GlobalConfigFields()
  return {}
end

function InstanceConfigFields()
-- todo: allow more than one path
  return {        ["path"] = "//depot/path/to/check/...",
           ["excludeUser"] = "User that can bypass the check, " ..
                             "e.g. git-fusion-user" }
end

function InstanceConfigEvents()
  init()
  local path = utils.iCfgData[ "path" ]
  return { ["change-submit"] = path, ["change-content"] = path }
end

function SplitPath( path )
  local i = 1
  local ps = {}

  for p in string.gmatch( path, "([^/]*)" ) do
    -- Skip the leading // in //depot.
    if string.len( p ) > 0 then
       ps[ i ] = p
       i = i + 1
    end
  end

  return ps
end

function SplitFileDir( path )
  local _, _, file = string.find( path, "([^/]*)$" )
  local dir = string.gsub( path, "([^/]*)$", "" )
  return dir, file  
end

function checkFile( depots, df )
   local ps = SplitPath( df )

   if not depots[ ps[ 1 ] ] then
      -- Depot doesn't exist.
      -- todo: add string to the translations
      return false, df, "no such depot"
   end
 
   local cidftab = p4:run( "files", "-e", "-i", df )

   if #cidftab == 0 then -- No exact file match.
      local d, f = SplitFileDir( df )
      local x = p4:run( "files", "-e", "-i", "-m1", d .. "*" )

      if #x == 0 then
	 -- No files in the dir, dir doesn't exist, 
	 return true
      end

      local xf = x[ 1 ][ "depotFile" ]
      local de, dff = SplitFileDir( xf )

      if de ~= d then
	 -- Path mismatch
	 return false, df, de
      end

      return true
   end

   local cidf = cidftab[ 1 ][ "depotFile" ]

   if df ~= cidf then
      return false, df, cidf
   end

   return true
end

function checkDepot( fs )
   local depots = {}
   local depots = p4:run( "depots" )

   for i, depot in ipairs( depots ) do
      depots[ depot[ "name" ] ] = true
   end

   for i, df in ipairs( fs ) do
      local r, err, ef = checkFile( depots, df )
      if not r then
	 return r, err, ef
      end
   end

   return true
end

function get_files_cc( change )
   local fs_all = p4:run( "files", "@=" .. change )
   if #fs_all == 0 then
      return {}
   end

   local fs = {}

   for i, dict in ipairs( fs_all ) do
      fs[ i ] = dict[ "depotFile" ]
   end

   return fs
end

function get_files( change )
   -- We'd like to be able to use an fstat like this, but it's not available until a change-content trigger.
   -- p4:run( "fstat", "-Ro", "-T", "depotFile,action", "-F", "^headAction=delete", "-e", change, "//..." )
   -- todo: restrict '//...' by the mapping?

   local all_fs = p4:run( "describe", "-s", change )
   all_fs = all_fs[ 1 ]
   local fs = {}
   local n = 1

   for i, action in ipairs( all_fs[ "action" ] ) do
      if action == "branch" or action == "add" then
	 fs[ n ] = all_fs[ "depotFile" ][ i ]
	 n = n + 1
      end
   end

   return fs
end

function run()
  init()

  if user == utils.iCfgData[ "excludeUser" ] then
    return true
  end

  local change = Helix.Core.Server.GetVar( "change" )
  local cmd    = Helix.Core.Server.GetVar( "command" )
  local fs

  p4 = P4.P4.new()
  p4:autoconnect()
  p4.exception_level = 0
  p4:connect()

  if cmd == "user-submit" then
     fs = get_files( change )
  end

  if cmd == "user-populate" then
     fs = get_files_cc( change )
  end

  local r, err, ef = checkDepot( fs )

  if not r then
     local msg = Helix.Core.Server.i18n.GetMessage( "errorMessage", err, ef )
     Helix.Core.Server.SetClientMsg( msg )
  end

  p4:disconnect()
  return r
end

function ChangeContent()
   -- The 'p4 populate' command does not fire the change-submit event.
   if Helix.Core.Server.GetVar( "command" ) ~= "user-populate" then
      return true
   end
   return run()
end

function ChangeSubmit()
   return run()
end