-- Copyright (C) 2018-2021 by KittenOS NEO contributors
--
-- Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
-- THIS SOFTWARE.

-- CRITICAL FILE!
-- This file defines how your KittenOS NEO system responds to access requests.
-- Modification, renaming or deletion can disable security features.
-- Usually, a change that breaks the ability for the file to do it's job will cause the "failsafe" to activate,
--  and for the system to become unable to run user applications.
-- However - I would not like to test this in a situation where said user applications were in any way untrusted,
--  for example, if you downloaded them from the Internet, or in particular if someone forwarded them over Discord.
-- IRC is usually pretty safe, but no guarantees.

-- Returns "allow", "deny", or "ask".
local function actualPolicy(pkg, pid, perm, pkgSvcPfx)
 -- System stuff is allowed.
 if pkg:sub(1, 4) == "sys-" then
  return "allow"
 end
 -- svc-t's job is solely to emulate terminals
 -- TO INSTALL YOUR OWN TERMINAL EMULATOR:
 -- perm|app-yourterm|r.neo.t
 if pkg == "svc-t" and perm == "r.neo.pub.t" then
  return "allow"
 end
 -- <The following is for apps & services>
 -- x.neo.pub.* is open to all
 if perm:sub(1, 10) == "x.neo.pub." then
  return "allow"
 end
 -- These signals are harmless, though they identify HW (as does everything in OC...)
 if perm == "s.h.component_added" or perm == "s.h.component_removed" or perm == "s.h.tablet_use" or perm == "c.tablet" then
  return "allow"
 end
 -- Userlevel can register for itself
 if perm == "r." .. pkgSvcPfx then
  return "allow"
 end
 -- Userlevel has no other registration rights
 if perm:sub(1, 2) == "r." then
  return "deny"
 end
 -- app/svc stuff is world-accessible,
 -- but note perm|*| overrides this
 if perm:sub(1, 6) == "x.app." then
  return "allow"
 end
 if perm:sub(1, 6) == "x.svc." then
  return "allow"
 end
 -- For hardware access, ASK!
 return "ask"
end

return function (nexus, settings, pkg, pid, perm, rsp, pkgSvcPfx)
 local res = actualPolicy(pkg, pid, perm, pkgSvcPfx)
 if settings then
  res = settings.getSetting("perm|" .. pkg .. "|" .. perm) or
        settings.getSetting("perm|*|" .. perm) or res
 end
 if res == "ask" and nexus then
  local totalW = 3 + 6 + 2 + 8
  local fmt = require("fmttext").fmtText(unicode.safeTextFormat(string.format("%s/%i wants:\n%s\nAllow this?\n\n", pkg, pid, perm)), totalW)
  local buttons = {
   {"<No>", function (w)
    rsp(false)
    nexus.windows[w.id] = nil
    w.close()
   end},
   {"<Always>", function (w)
    if settings then
     settings.setSetting("perm|" .. pkg .. "|" .. perm, "allow")
    end
    rsp(true)
    nexus.windows[w.id] = nil
    w.close()
   end},
   {"<Yes>", function (w)
    rsp(true)
    nexus.windows[w.id] = nil
    w.close()
   end}
  }
  local cButton = 0
  nexus.create(totalW, #fmt, "security", function (window, ev, a, b, c)
   while ev do
    if ev == "line" or ev == "touch" then
     local cor = b
     local iev = ev
     ev = nil
     if iev == "line" then
      cor = a
      if fmt[a] then
       window.span(1, a, fmt[a], 0xFFFFFF, 0)
      end
     end
     if cor == #fmt then
      local x = 1
      for k, v in ipairs(buttons) do
       if iev == "line" then
        if k ~= cButton + 1 then
         window.span(x, a, v[1], 0xFFFFFF, 0)
        else
         window.span(x, a, v[1], 0, 0xFFFFFF)
        end
       elseif a >= x and a < (x + #v[1]) then
        cButton = k - 1
        ev = "key"
        a = 32
        b = 0
        c = true
        break
       end
       x = x + #v[1] + 1
      end
     end
    elseif ev == "close" then
     rsp(false)
     nexus.windows[window.id] = nil
     window.close()
     ev = nil
    elseif ev == "key" then
     if c and (a == 9 or b == 205) then
      cButton = (cButton + 1) % #buttons
      ev = "line"
      a = #fmt
     elseif c and b == 203 then
      cButton = (cButton - 1) % #buttons
      ev = "line"
      a = #fmt
     elseif c and (a == 13 or a == 32) then
      buttons[cButton + 1][2](window)
      ev = nil
     else
      ev = nil
     end
    else
     ev = nil
    end
   end
  end)
 else
  rsp(res == "allow")
 end
end