--[[
Eat It - a Mpv plugin manager

Copyright © 2023 squibid

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
]]

local mp = require('mp')

-- load the config file
dofile(mp.command_native({'expand-path', '~~/eatit-cfg.lua'}))

-- helper functions --
local function tablelength(T)
  local count = 0
  for _ in pairs(T) do count = count + 1 end
  return count
end

local function fileexists(name)
   local ok, err, code = os.rename(name, name)
   if not ok then
      if code == 13 then
         -- Permission denied, but it exists
         return true
      end
   end
   return ok, err
end

local function testforslash(str)
  if string.match(str, '/') then
    return string.match(str, '/([^/]+)$')
  else
    return str
  end
end

local function run(cmd)
  local x = io.popen(cmd)
  local y = x:read("*a")
  x:close()
  return y
end

local function openlog()
  if opts.logging.log then -- log if asked to
    -- get our logfile's full path
    fn = mp.command_native({'expand-path', opts.logging.logfile})

    f = io.open(fn, 'a') -- open file buffer
    io.output(f) -- set it as default
  end
end

local function logwrite(string)
  if opts.logging.log then
    io.write(os.date(opts.logging.logdate) .. ' ' .. string .. '\n')
  end
end

local function closelog()
  if opts.logging.log then
    io.close(f)
  end
end

-- get the requested git repos
local function clonegit(plugdir, i)
  logwrite('downloading ' .. plugins[i][1])

  -- clone the repo
  -- BUG: logwriting the git command doens't actually log the output
  run('git -C ' .. opts.dl.dir .. ' clone ' .. plugins[i][1])
  run('git -C ' .. plugdir .. ' checkout -q ' .. plugins[i]['branch'])
end

-- check for updates
local function checkupdates(plugdir)
  local localhash = run('git -C ' .. plugdir .. ' log -1 --format=format:"%H"')
  local remotehash = run('git -C ' .. plugdir .. ' rev-parse $(git -C ' ..
    plugdir .. ' branch -r) | tail -1')
  if localhash ~= remotehash then return true else return false end
end

-- start install
local function startinstall()
  -- let the user know that we are starting install
  logwrite('Starting Download...')
  mp.osd_message('Downloading plugins!')

  -- start iterating through plugins
  for i = 1, tablelength(plugins) do
    -- check if the user has defined a file for the current plugin
    if not plugins[i]['file'] then
      logwrite('WARNING! Git repo "' .. plugins[i][1] ..
        '" doesn\'t have a specified file. Skipping download')

      -- FIXME: this results in the last plugin being downloaded & copied twice
      i = i + 1 -- if not we go to the next plugin
    end

    -- if no destdir defined we set it to the root of the mpv config dir
    if not plugins[i]['dir'] then
      plugins[i]['dir'] = '~~/'
    end

    -- get the file's dir
    local pluginfile = opts.dl.dir .. '/' ..
      string.match(plugins[i][1], '/([^/]+)$'):gsub('.git', '') ..
      '/' .. plugins[i]['file']

    -- get the dest dir
    local destfile = mp.command_native({'expand-path', '~~/'}) ..
      '/' .. plugins[i]['dir'] ..
      '/' .. plugins[i]['file']

    if fileexists(pluginfile) then
      -- if we need to update, update
      if checkupdates(i) then
        logwrite(plugins[i]['file'] .. ' is updating.')
        clonegit(i)
      else
        logwrite(plugins[i]['file'] .. ' is up to date!')
      end
    else
      clonegit(i)
    end

    -- copy the file contents over to the desired location
    local infile = io.open(pluginfile, 'r')
    local outfile = io.open(destfile, 'w')
    outfile:write(infile:read('*a'))
    outfile:close()
    infile:close()
  end
end

local function initupdate()
  openlog()

  logwrite('# of plugins defined in table: ' .. tablelength(plugins))
  os.execute('mkdir -p ' .. opts.dl.dir) -- make download dir
  startinstall()

  -- closing/removing everything
  if opts.dl.powerwash == true then
    logwrite('powerwashing the tmp dir "' .. opts.dl.dir .. '"')
    os.execute('rm -rf ' .. opts.dl.dir)
  end

  closelog()
end

-- run any user defined configs at startup
-- NOTE: This is kinda useless and might be removed if there is no way to make
-- it run in the desired plugin's thread
local function runopts()
  openlog()
  for i = 1, tablelength(plugins) do
    if plugins[i]['cfg'] then
      logwrite('Running ' .. plugins[i]['file'] .. '\'s config')
      plugins[i]['cfg']()
    end
  end
  closelog()
end

-- remove logfile on startup
if opts.logging.log then
  openlog()
  os.remove(fn)
  closelog()
end

runopts()
mp.add_key_binding(opts.bind, 'UpdatePlugins', initupdate)