#!/usr/bin/env texlua
-------------------------------------------------------------------------------
--         FILE:  mkimport.lua
--        USAGE:  ./mkimport.lua
--  DESCRIPTION:  check luaotfload imports against Context
-- REQUIREMENTS:  luatex, the lualibs package, Context MkIV
--       AUTHOR:  Philipp Gesang (Phg), <phg@phi-gamma.net>
--      VERSION:  42
--      CREATED:  2014-12-08 22:36:15+0100
-------------------------------------------------------------------------------
--

-------------------------------------------------------------------------------
--- PURPOSE
--- 
---  - Facilitate detecting changes in the fontloader source.
---  - Assist in updating source code and (partially) automate importing.
---  - Account for files in the plain fontloader distribution, alert in case of
---    additions or deletions.
---    
-------------------------------------------------------------------------------

local debug = false

kpse.set_program_name "luatex"

local lfs = require "lfs"
local md5 = require "md5"

require "lualibs"

local fileiswritable   = file.is_writable
local ioloaddata       = io.loaddata
local iopopen          = io.popen
local iowrite          = io.write
local lfschdir         = lfs.chdir
local lfsisdir         = lfs.isdir
local lfsisfile        = lfs.isfile
local md5sumhexa       = md5.sumhexa
local osgettimeofday   = os.gettimeofday
local stringformat     = string.format
local tableconcat      = table.concat

-------------------------------------------------------------------------------
-- config
-------------------------------------------------------------------------------

local context_root        = "/home/phg/context/tex/texmf-context"
local our_prefix          = "fontloader"
local luatex_fonts_prefix = "luatex"
local fontloader_subdir   = "src/fontloader"

local origin_paths = {
  context    = "tex/context/base",
  fontloader = "tex/generic/context/luatex",
}

local subdirs = {
  "runtime",
  "misc"
}

local searchdirs = {
  --- order is important!
  fontloader_subdir,
  context_root
}

local prefixes = {
  context    = nil,
  fontloader = "luatex",
}

-------------------------------------------------------------------------------
-- helpers
-------------------------------------------------------------------------------

local die = function (...)
  io.stderr:write "[\x1b[1;30;41mfatal error\x1b[0m]: "
  io.stderr:write (stringformat (...))
  io.stderr:write "\naborting.\n"
  os.exit (1)
end

local emphasis = function (txt)
  return stringformat("\x1b[1m%s\x1b[0m", txt)
end

local msg = function (...)
  iowrite (stringformat (...))
  iowrite "\n"
end

local separator_string = string.rep ("-", 79)
local separator = function ()
  iowrite (separator_string)
  iowrite "\n"
end

local good_tag   = stringformat("[\x1b[1;30;%dmgood\x1b[0m]   · ", 42)
local bad_tag    = stringformat("[\x1b[1;30;%dmBAD\x1b[0m]    · ", 41)
local alert_tag  = stringformat("[\x1b[1;%dmalert\x1b[0m]  · "   , 36)
local status_tag = stringformat("[\x1b[0;%dmstatus\x1b[0m] · "   , 36)

local good = function (...)
  local msg = (stringformat (...))
  iowrite (good_tag)
  iowrite (msg)
  iowrite "\n"
end

local bad = function (...)
  local msg = (stringformat (...))
  iowrite (bad_tag)
  iowrite (msg)
  iowrite "\n"
end

local attention = function (...)
  local msg = (stringformat (...))
  iowrite (alert_tag)
  iowrite (msg)
  iowrite "\n"
end

local status = function (...)
  local msg = (stringformat (...))
  iowrite (status_tag)
  iowrite (msg)
  iowrite "\n"
end

-------------------------------------------------------------------------------
-- definitions
-------------------------------------------------------------------------------

--- Accounting of upstream files. There are different categories:
---
---   · *essential*: Files required at runtime.
---   · *merged*:    Files merged into the fontloader package.
---   · *ignored*:   Lua files not merged, but part of the format.
---   · *tex*:       TeX code, i.e. format and examples.
---   · *lualibs*:   Files merged, but also provided by the Lualibs package.

local kind_essential = 0
local kind_merged    = 1
local kind_tex       = 2
local kind_ignored   = 3
local kind_lualibs   = 4

local kind_name = {
  [0] = "essential",
  [1] = "merged"   ,
  [2] = "tex"      ,
  [3] = "ignored"  ,
  [4] = "lualibs"  ,
}

local imports = {

  fontloader = {
    { name = "basics-gen"        , ours = nil          , kind = kind_essential },
    { name = "basics-nod"        , ours = nil          , kind = kind_merged    },
    { name = "basics"            , ours = nil          , kind = kind_tex       },
    { name = "fonts-cbk"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-def"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-demo-vf-1"   , ours = nil          , kind = kind_ignored   },
    { name = "fonts-enc"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-ext"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-inj"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-lua"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-merged"      , ours = "fontloader" , kind = kind_essential },
    { name = "fonts-ota"         , ours = nil          , kind = kind_merged    },
    { name = "fonts-otn"         , ours = nil          , kind = kind_merged    },
    { name = "fonts"             , ours = nil          , kind = kind_merged    },
    { name = "fonts"             , ours = nil          , kind = kind_tex       },
    { name = "fonts-syn"         , ours = nil          , kind = kind_ignored   },
    { name = "fonts-tfm"         , ours = nil          , kind = kind_merged    },
    { name = "languages"         , ours = nil          , kind = kind_ignored   },
    { name = "languages"         , ours = nil          , kind = kind_tex       },
    { name = "math"              , ours = nil          , kind = kind_ignored   },
    { name = "math"              , ours = nil          , kind = kind_tex       },
    { name = "mplib"             , ours = nil          , kind = kind_ignored   },
    { name = "mplib"             , ours = nil          , kind = kind_tex       },
    { name = "plain"             , ours = nil          , kind = kind_tex       },
    { name = "preprocessor"      , ours = nil          , kind = kind_ignored   },
    { name = "preprocessor"      , ours = nil          , kind = kind_tex       },
    { name = "preprocessor-test" , ours = nil          , kind = kind_tex       },
    { name = "swiglib"           , ours = nil          , kind = kind_ignored   },
    { name = "swiglib"           , ours = nil          , kind = kind_tex       },
    { name = "swiglib-test"      , ours = nil          , kind = kind_ignored   },
    { name = "swiglib-test"      , ours = nil          , kind = kind_tex       },
    { name = "test"              , ours = nil          , kind = kind_tex       },
  }, --[[ [fontloader] ]]

  context = { --=> all merged
    { name = "data-con"          , ours = "data-con"          , kind = kind_merged    },
    { name = "font-afk"          , ours = "font-afk"          , kind = kind_merged    },
    { name = "font-afm"          , ours = "font-afm"          , kind = kind_merged    },
    { name = "font-cid"          , ours = "font-cid"          , kind = kind_merged    },
    { name = "font-con"          , ours = "font-con"          , kind = kind_merged    },
    { name = "font-def"          , ours = "font-def"          , kind = kind_merged    },
    { name = "font-ini"          , ours = "font-ini"          , kind = kind_merged    },
    { name = "font-map"          , ours = "font-map"          , kind = kind_merged    },
    { name = "font-otb"          , ours = "font-otb"          , kind = kind_merged    },
    { name = "font-otf"          , ours = "font-otf"          , kind = kind_merged    },
    { name = "font-oti"          , ours = "font-oti"          , kind = kind_merged    },
    { name = "font-otp"          , ours = "font-otp"          , kind = kind_merged    },
    { name = "font-tfm"          , ours = "font-tfm"          , kind = kind_merged    },
    { name = "l-boolean"         , ours = "l-boolean"         , kind = kind_lualibs   },
    { name = "l-file"            , ours = "l-file"            , kind = kind_lualibs   },
    { name = "l-function"        , ours = "l-function"        , kind = kind_lualibs   },
    { name = "l-io"              , ours = "l-io"              , kind = kind_lualibs   },
    { name = "l-lpeg"            , ours = "l-lpeg"            , kind = kind_lualibs   },
    { name = "l-lua"             , ours = "l-lua"             , kind = kind_lualibs   },
    { name = "l-math"            , ours = "l-math"            , kind = kind_lualibs   },
    { name = "l-string"          , ours = "l-string"          , kind = kind_lualibs   },
    { name = "l-table"           , ours = "l-table"           , kind = kind_lualibs   },
    { name = "util-str"          , ours = "util-str"          , kind = kind_lualibs   },
  }, --[[ [context] ]]
} --[[ [imports] ]]

local hash_file = function (fname)
  if not lfsisfile (fname) then
    die ("cannot find %s.", fname)
  end
  local raw = ioloaddata (fname)
  if not raw then
    die ("cannot read from %s.", fname)
  end
  return md5sumhexa (raw)
end

local derive_category_path = function (cat)
  local subpath  = origin_paths[cat] or die ("category " .. cat .. " unknown")
  local location = file.join (context_root, subpath)
  if not lfsisdir (location) then
    die ("invalid base path defined for category "
         .. cat .. " at " .. location)
  end
  return location
end

local derive_suffix = function (kind)
  if kind == kind_tex then return ".tex" end
  return ".lua"
end

local pfxlen = { }
local strip_prefix = function (fname, prefix)
  prefix = prefix or our_prefix
  if not pfxlen[prefix] then pfxlen[prefix] = #prefix end
  local len = pfxlen[prefix]
  if #fname <= len + 2 then
    --- too short to accomodate prefix + basename
    return
  end
  if string.sub (fname, 1, len) == prefix then
    return string.sub (fname, len + 2)
  end
end

local derive_fullname = function (cat, name, kind)
  local tmp = prefixes[cat]
  tmp = tmp and tmp .. "-" .. name or name
  return tmp .. derive_suffix (kind)
end

local derive_ourname = function (name, kind)
  local suffix = derive_suffix (kind)
  local subdir = kind == kind_essential and "runtime" or "misc"
  return subdir, our_prefix .. "-" .. name .. suffix
end

local format_file_definition = function (def)
  return stringformat ("name = \"%s\", kind = \"%s\"",
                       def.name,
                       kind_name[def.kind] or def.kind)
      .. (def.ours and (", ours = \"" .. def.ours .. "\"") or "")
end

local is_readable = function (f)
  local fh = io.open (f, "r")
  if fh then
    fh:close()
    return true
  end
  return false
end

local summarize_news = function (status)
  local ni = #status.import
  local nc = #status.create
  local ng = #status.good
  local nm = #status.missing

  separator ()
  msg ("Summary: Inspected %d files.", ni + nc + ng + nm)
  separator ()
  if ng > 0 then good      ("%d are up to date", ng) end
  if ni > 0 then attention ("%d changed"       , ni) end
  if nc > 0 then attention ("%d new"           , nc) end
  if nm > 0 then bad       ("%d missing"       , nm) end
  separator ()

  if nm == 0 and nc == 0 and ni == 0 then
    return 0
  end

  return -1
end

local news = function ()
  local status = {
    import  = { },
    good    = { },
    create  = { },
    missing = { },
  }

  for cat, entries in next, imports do
    local location = derive_category_path (cat)
    local nfiles = #entries

    for i = 1, nfiles do
      local def  = entries[i]
      local name = def.name
      local ours = def.ours
      local kind = def.kind
      local fullname = derive_fullname (cat, name, kind)
      local fullpath = file.join (location, fullname)
      local subdir, ourname  = derive_ourname (ours or name, kind)
      local ourpath  = file.join (fontloader_subdir, subdir, ourname) -- relative
      local imported = false

      if not is_readable (fullpath) then
        bad ("source for file %s not found at %s",
             emphasis (ourname),
             emphasis (fullpath))
        status.missing[#status.missing + 1] = ourname
      else
        --- Source file exists and is readable.
        if not lfsisdir (fontloader_subdir) then
          die ("path for fontloader tree ("
              .. fontloader_subdir .. ") is not a directory")
        end
        if is_readable (ourpath) then imported = true end
        local src_hash = hash_file (fullpath)
        local dst_hash = imported and hash_file (ourpath)
        local same     = src_hash == dst_hash -- same!

        if same then
          good ("file %s unchanged", emphasis (ourname))
          status.good[#status.good + 1] = ourname
        elseif not dst_hash then
          attention ("new file %s requires import from %s",
                    emphasis (ourname),
                    emphasis (fullpath))
          status.create[#status.create + 1] = ourname
        else --- src and dst exist but differ
          attention ("file %s requires import", emphasis (ourname))
          status.import[#status.import + 1] = ourname
        end
      end

    end
  end

  return summarize_news (status)
end --[[ [local news = function ()] ]]

local get_file_definition = function (name, ourname, kind)
  kind = kind or "lua"
  for cat, defs in next, imports do
    local fullname = derive_fullname (cat, name, kind)
    local ndefs = #defs
    for i = 1, ndefs do
      local def = defs[i]
      local dname = def.name
      local dours = def.ours or def.name
      local dkind = def.kind

      --- test properties
      local subdir, derived = derive_ourname (dours, dkind)
      if                             derived == ourname  then return def, cat end
      if derive_fullname (cat, dname, dkind) == fullname then return def, cat end
      if                               dours == ourname  then return def, cat end
      if                               dname == fullname then return def, cat end
    end
  end
  --- search unsuccessful
end --[[ [local get_file_definition = function (name, ourname, kind)] ]]

local import_imported = 0
local import_skipped  = 1
local import_failed   = 2
local import_created  = 3

local import_status = {
  [import_imported] = "imported",
  [import_skipped ] = "skipped",
  [import_failed  ] = "failed",
  [import_created ] = "created",
}

local summarize_status = function (counters)
  local imported = counters[import_imported] or 0
  local skipped  = counters[import_skipped ] or 0
  local created  = counters[import_created ] or 0
  local failed   = counters[import_failed  ] or 0
  local sum = imported + skipped + created + failed
  if sum < 1 then die ("garbage total of imported files: %s", sum) end
  separator ()
  status (" RESULT: %d files processed", sum)
  separator ()
  if created  > 0 then status ("created:  %d (%d %%)", created , created  * 100 / sum) end
  if imported > 0 then status ("imported: %d (%d %%)", imported, imported * 100 / sum) end
  if skipped  > 0 then status ("skipped:  %d (%d %%)", skipped , skipped  * 100 / sum) end
  separator ()
end

local import_file = function (name, kind, def, cat)
  local expected_ourname = derive_ourname (name)
  if not def or not cat then
    def, cat = get_file_definition (name, expected_ourname, kind)
  end

  if not def then die ("unable to find a definition matching " .. name) end
  if not cat then die ("missing category for file " .. name .. " -- WTF‽") end

  local dname    = def.name
  local dours    = def.ours or dname
  local dkind    = def.kind
  local srcdir   = derive_category_path (cat)
  local fullname = derive_fullname (cat, dname, kind)
  local subdir, ourname = derive_ourname (dours, kind)
  local ourpath  = file.join (fontloader_subdir, subdir)
  local src      = file.join (srcdir, fullname)
  local dst      = file.join (ourpath, ourname)
  local new      = not lfsisfile (dst)
  if not new and hash_file (src) == hash_file (dst) then
    status ("file %s is unchanged, skipping", fullname)
    return import_skipped
  end
  if not (lfsisdir (ourpath) or not lfs.mkdirs (ourpath)) then
    die ("failed to create directory %s for file %s",
         ourpath, ourname)
  end
  status ("importing file %s", fullname)
  file.copy (src, dst)
  if hash_file (src) == hash_file (dst) then
    if new then return import_created end
    return import_imported end
  return import_failed
end --[[ [local import_file = function (name, kind)] ]]

local import = function (arg)
  if #arg > 1 then
    local name = arg[2] or die ("invalid filename " .. tostring (arg[2]))
    local stat = import_file (name)
    if stat == import_failed then
      die ("failed to import file " .. name)
    end
    status ("import status for file %s: %s", name, import_status[stat])
  end
  --- Multiple files
  local statcount = { } -- import status codes -> size_t
  for cat, defs in next, imports do
    local ndefs = #defs
    for i = 1, ndefs do
      local def  = defs[i]
      local stat = import_file (def.name, def.kind, def, cat)
      if stat == import_failed then
        die (stringformat ("import failed at file %d of %d (%s)",
                           i, ndefs, def.name))
      end
      statcount[stat] = statcount[stat] or 0
      statcount[stat] = statcount[stat] + 1
    end
  end
  summarize_status (statcount)
  return 0
end --[[ [local import = function (arg)] ]]

local find_in_path = function (root, subdir, target)
  local file = file.join (root, subdir, target)
  if lfsisfile (file) then
    return file
  end
end

local search_paths = function (target)
  for i = 1, #searchdirs do
    local root  = searchdirs[i]

    for j = 1, #subdirs do
      local found = find_in_path (root, subdirs[j], target)
      if found then return found end
    end

  end

  local found = find_in_path (context_root, origin_paths.context, target)
  if found then return found end

  local found = find_in_path (context_root, origin_paths.fontloader, target)
  if found then return found end
  return false
end

local search_defs = function (target)
  local variants = { target, --[[ unstripped ]] }
  local tmp
  tmp = strip_prefix (target)
  if tmp then variants[#variants + 1] = tmp end
  tmp = strip_prefix (target, luatex_fonts_prefix)
  if tmp then variants[#variants + 1] = tmp end

  local nvariants = #variants

  for cat, defs in next, imports do
    local ndefs = #defs
    for i = 1, ndefs do
      local def = defs[i]

      for i = 1, nvariants do
        local variant = variants[i]

        local dname = def.name
        if variant == dname then
          local found = search_paths (variant .. derive_suffix (def.kind))
          if found then return found end
        end

        local dkind = def.kind
        local dfull = derive_fullname (cat, dname, dkind)
        if derive_fullname (cat, variant, dkind) == dfull then
          local found = search_paths (dfull)
          if found then return found end
        end

        local dours = def.ours
        if dours then

          local _, ourname = derive_ourname (dours, dkind)
          if variant == dours then
            local found = search_paths (ourname)
            if found then return found end
          end

          if variant == ourname then
            local found = search_paths (ourname)
            if found then return found end
          end
        end

      end
    end
  end
  return false
end

local search = function (target)
  local look_for
  --- pick a file
  if lfsisfile (target) then --- absolute path given
    look_for = target
    goto found
  else

    --- search as file name in local tree
    look_for = search_paths (target)
    if look_for then goto found end

    --- seach the definitions
    look_for = search_defs (target)
    if look_for then goto found end

  end

::fail::
  if not look_for then return end

::found::
  return look_for
end

local find_matching_def = function (location)
  local basename = file.basename (location)
  if not basename then die ("corrupt path %s", location) end
  local barename = file.removesuffix (basename)
  local pfxless  = strip_prefix (barename)
  local kind     = file.suffix (pfxless) or "lua"
  for cat, defs in next, imports do
    for _, def in next, defs do
      local dname = def.name
      local dours = def.ours
      if dname == pfxless
      or dname == barename
      -- dname == basename -- can’t happen for lack of suffix
      or dours == pfxless
      or dours == barename
      then
        return cat, def
      end
    end
  end
  return false
end

local describe = function (target, location)
  --- Map files to import definitions
  separator ()
  status ("found file %s at %s", target, location)
  local cat, def = find_matching_def (location)
  if not cat or not def then
    die ("file %s not found in registry", location)
  end

  local dname           = def.name
  local dkind           = def.kind
  local subdir, ourname = derive_ourname (def.ours or dname, dkind)
  separator ()
  status ("category       %s", cat)
  status ("kind           %s", kind_name[dkind])
  status ("in Context     %s", derive_fullname (cat, dname, dkind))
  status ("in Luaotfload  %s", ourname)
  separator ()
  return 0
end

local tell = function (arg)
  local target = arg[2]
  if not target then die "no filename given" end

  local location = search (target)
  if not location then
    die ("file %s not found in any of the search locations", target)
  end

  return describe (target, location)
end

--[[doc--

  Packaging works as follows:

      * Files are looked up the usual way, allowing us to override the
        distribution-supplied scripts with our own alternatives in the
        local path.

      * The merged package is written to the same directory as the
        packaging script (not ``$PWD``).

  There is some room for improvements: Instead of reading a file with
  fixed content from disk, the merge script could be composed
  on-the-fly from a list of files and then written to memory (not sure
  though if we can access shm_open or memfd and the likes from Lua).

--doc]]--

local package = function (args)
  local t0          = osgettimeofday ()
  local orig_dir    = lfs.currentdir ()
  local base_dir    = orig_dir .. "/src/fontloader/"
  local merge_name  = base_dir .. "luaotfload-package.lua"
  --- output name is fixed so we have to deal with it but maybe we can
  --- get a patch to mtx-package upstreamed in the future
  local output_name = base_dir .. "luaotfload-package-merged.lua"
  local target_name = stringformat ("fontloader-%s.lua",
                                    os.date ("%F"))
  status ("assuming fontloader source in      %s", base_dir)
  status ("reading merge instructions from    %s", merge_name)
  status ("writing output to                  %s", target_name)

  --- check preconditions

  if not lfsisdir (base_dir)          then die ("directory %s does not exist", emphasis (base_dir   )) end
  if not lfsisfile (merge_name)       then die ("missing merge file at %s",    emphasis (merge_name )) end
  if not fileiswritable (output_name) then die ("cannot write to %s",          emphasis (output_name)) end
  if not fileiswritable (target_name) then die ("cannot write to %s",          emphasis (target_name)) end
  if not lfschdir (base_dir)          then die ("failed to cd into %s",        emphasis (base_dir   )) end

  if lfsisfile (output_name) then
    status ("output file already exists at “%s”, unlinking", output_name)
    local ret, err = os.remove (output_name)
    if ret == nil then
      if not lfschdir (orig_dir) then
        status ("warning: failed to cd retour into %s", emphasis (orig_dir))
      end
      die ("failed to remove existing merge package")
    end
  end
    --die ("missing merge file at %s",    emphasis (merge_name )) end

  --- perform merge

  local cmd = { "mtxrun", "--script", "package", "--merge", merge_name }
  local shl = tableconcat (cmd, " ")

  status ("invoking %s as “%s”", emphasis "mtx-package", shl)

  local fh = iopopen (shl, "r")

  if not fh then
    if not lfschdir (orig_dir) then
      status ("warning: failed to cd retour into %s", emphasis (orig_dir))
    end
    die ("merge failed; failed to invoke mtxrun")
  end

  local junk = fh.read (fh, "*all")
  if not junk then
    status ("warning: received no output from mtxrun; this is strange")
  end

  fh.close (fh)

  if debug then print (junk) end

  --- clean up

  if not lfschdir (orig_dir) then
    status ("warning: failed to cd retour into %s", emphasis (orig_dir))
  end

  --- check postconditions

  if not lfsisfile (output_name) then die ("merge failed; package not found at " .. output_name)   end

  --- at this point we know that mtxrun was invoked correctly and the
  --- result file has been created

  status ("merge complete; operation finished in %.0f ms",
          (osgettimeofday() - t0) * 1000)
end

local help = function ()
  iowrite "usage: mkimport  <command> [<args>]\n"
  iowrite "\n"
  iowrite "Where <command> is one of\n"
  iowrite "   help      Print this help message\n"
  iowrite "   tell      Display information about a file’s integration\n"
  iowrite "   news      Check Context for updated files\n"
  iowrite "   import    Update with files from Context\n"
  iowrite "   package   Invoke mtx-package on the current fontloader\n"
  iowrite "\n"
end

local job_kind = table.mirrored {
  help    = help,
  import  = import,
  news    = news,
  package = package,
  tell    = tell,
}

-------------------------------------------------------------------------------
-- functionality
-------------------------------------------------------------------------------

--- job_kind -> bool
local check_job = function (j)
  return job_kind[j] or die ("invalid job type “%s”.", j)
end

-------------------------------------------------------------------------------
-- entry point
-------------------------------------------------------------------------------

local main = function ()
  local job = arg[1] or "help"
  local runner = check_job (job)
  return runner(arg)
end

os.exit (main ())

--- vim:ft=lua:ts=2:et:sw=2