local serial = require "serialization"
local unicode = require "unicode"
local fs = require "filesystem"
local event = require "event"

local tArgs = {...}
local ipackages = {} -- installed packages
local rpath = tArgs[1] or install.from
local tpath = tArgs[2] or install.to
if tpath == "//" then
 tpath = "/usr/"
end

tpath, rpath = fs.canonical(tpath), fs.canonical(rpath)

local fobj = io.open(rpath.."/master/programs.cfg","rb") -- read packages list from floppy
if not fobj then
 error("installer disk not properly configured")
end
local packages = serial.unserialize(fobj:read("*a"))
fobj:close()

local function ripackages()
 local fobj = io.open("/etc/opdata.svd","rb") -- attempt to read installed packages
 if fobj then
  ipackages = serial.unserialize(fobj:read("*a"))
  fobj:close()
 end
end
ripackages()

local function wipackages()
 local fobj = io.open("/etc/opdata.svd","wb") -- attempt to read installed packages
 if fobj then
  fobj:write(serial.serialize(ipackages))
  fobj:close()
 end
end

local pkgmap = {} -- alphabetically sorted list of package names
for k,v in pairs(packages) do
 pkgmap[#pkgmap+1] = k
end
table.sort(pkgmap)

local function clear()
 io.write("\27[2J\27[H")
end

function info(pkg) -- shows info for pkg
 clear()
 local fh = io.popen("less","w")
 local function print(str)
  fh:write(str.."\n")
 end
 print(string.format("%s - %s",pkg,packages[pkg].name))
 print(packages[pkg].description)
 if packages[pkg].files then
  print("\nFiles:")
  for k,v in pairs(packages[pkg].files) do
   print(string.format("%s -> %s",k,v))
  end
 end
 if packages[pkg].dependencies then
  print("\nDependencies")
  for k,v in pairs(packages[pkg].dependencies) do
   print(" - "..k)
  end
 end
 fh:close()
end

local preamble = false
local fobj = io.open(rpath.."/.info","rb") -- read the pre-inst screen
if fobj then
 preamble = fobj:read("*a")
 fobj:close()
end

if preamble then -- display pre-inst screen
 clear()
 if install.label then
  print(install.label .. " installer")
 end
 print(preamble)
 print("Press any key to continue.")
 event.pull("key_down")
end

local mx, my = require("term").getViewport()
local selected, start = 1, 1

local function drawmenu() -- draw the menu display - nothing but text and VT100 escape codes
 local infostring = string.format("[%s][%s]%s", unicode.char(0x2191), unicode.char(0x2193), " Move [Space] (De)select [i] More Info [q] Quit [Enter] Confirm")
 clear()
 io.write(string.format("\27[%d;1H%s\27[H",my,infostring))
 local workingSpace = my - math.ceil(infostring:len() / mx) - 1
 if install.label then
  print(install.label .. " installer")
  workingSpace = workingSpace - 1
 end
 if selected > start + workingSpace - 3 then
  start = math.min(start + 3, #pkgmap - workingSpace)
 elseif selected < start + 3 then
  start = math.max(start - 3, 1)
 end
 for k = start, math.min(#pkgmap,start+workingSpace) do
  local v = pkgmap[k]
  if k == selected then
   io.write("\27[30;47m")
  end
  if packages[v].selected then
   io.write(" "..unicode.char(0x25A0).." ")
  else
   io.write(" "..unicode.char(0x25A1).." ")
  end
  io.write(v)
  print("\27[0m")
 end
end

--[[
Key codes:
0 208 down
0 200 up
13 28 enter
32 57 space
105 23 i
113 16 q
121 21 y
]]--

local run, install = true, true
while run do -- menu loop
 drawmenu()
 local _, _, ch, co = event.pull("key_down")
 if ch == 13 and co == 28 then
  run = false
 elseif ch == 113 and co == 16 then
  run = false
  install = false
 elseif ch == 105 and co == 23 then
  info(pkgmap[selected])
 elseif ch == 0 and co == 208 then
  selected = selected + 1
  if selected > #pkgmap then
   selected = #pkgmap
  end
 elseif ch == 0 and co == 200 then
  selected = selected - 1
  if selected < 1 then
   selected = 1
  end
 elseif ch == 32 and co == 57 then
  packages[pkgmap[selected]].selected = not packages[pkgmap[selected]].selected
 end
end

clear()

if not install then -- pressed q
 print("Aborted.")
 return
end

local toinstall, postinstall = {}, {} -- table of commands to run after installation

print("Resolving dependencies...") -- build a table of what to install
for k,v in pairs(packages) do
 if v.selected then
  toinstall[k] = true
  if v.dependencies then
   for l,m in pairs(v.dependencies) do -- including dependencies
    if not toinstall[l] then
     print("Package "..k.." depends on "..l)
     toinstall[l] = m
    end
   end
  end
 end
end

print("You have selected to install the following packages to "..tpath..":")
for k,v in pairs(toinstall) do
  print(" - "..k)
end
print("Continue? [y/N] ")
_, _, _, co = event.pull("key_down")
if co ~= 21 then -- confirm they want the packages installed
 print("Aborted.")
 return
end

local function install(pkg,where) -- installs a package, pkg, to where
 where = where or tpath
 if type(where) ~= string then where = tpath end
 print("Installing "..pkg.."...")
 if packages[pkg] then
  ipackages[pkg] = {}
  print("Copying files...")
  for l,m in pairs(packages[pkg].files) do
   local lseg = fs.segments(l)
   if m:sub(1,2) ~= "//" then
    if not fs.exists(fs.canonical(where.."/"..m)) then
     os.execute("mkdir "..fs.canonical(where.."/"..m))
    end
    if l:sub(1,4) == "http" then
     os.execute("cp -v "..rpath.."/external/"..l:match(".+/(.+)").." "..fs.canonical(where.."/"..m))
    else
     os.execute("cp -v "..rpath.."/"..l.." "..fs.canonical(where.."/"..m))
    end
    ipackages[pkg][l] = fs.canonical(where.."/"..m).."/"..lseg[#lseg]
   else
    if not fs.exists(fs.canonical(m:sub(2))) then
     os.execute("mkdir "..fs.canonical(m:sub(2)))
    end
    if l:sub(1,4) == "http" then
     os.execute("cp -v "..rpath.."/external/"..l:match(".+/(.+)").." "..fs.canonical(m))
    else
     os.execute("cp -v "..rpath.."/"..l.." "..fs.canonical(m))
    end
    ipackages[pkg][l] = fs.canonical(m:sub(2)).."/"..lseg[#lseg]
   end
  end
  if packages[pkg].postinstall then
   for k,v in pairs(packages[pkg].postinstall) do
    postinstall[#postinstall+1] = v
   end
  end
 else
  print("Package not on disk. Attempting to install via oppm.")
  print("oppm install "..pkg.." "..where)
  wipackages()
  os.execute("oppm install "..pkg.." "..where)
  ripackages()
 end
 wipackages()
end

for k,v in pairs(toinstall) do
 install(k,v)
end

if #postinstall > 0 then
 print("Running post-install commands...")
 for k,v in pairs(postinstall) do
  print(v)
  os.execute(v)
 end
end