--[[
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)
  if not x then return 1 end
  local y = x:read("*a")
  x:close()
  return y
end

local function cp(a, b)
  local i = io.open(a, 'r')
  if not i then return 1 end
  local o = io.open(b, 'w')
  if not o then return 2 end
  o:write(i:read('*a'))
  o:close()
  i:close()
end

local function getsrc(id)
  local src
  if string.find(id, ":") then src = id:match("^[a-z]+[^:]") end
  local name = id:match([[[^:]*$]])
  if name then
    local pre = opts.nameexp.pre or "https://"
    local map = opts.nameexp.map or {
      gl = 'gitlab.com',
      cb = 'codeberg.org',
      sr = 'sr.ht',
      gh = 'github.com'
    }
    return {
      link = (pre..map[src]) or false,
      repo = name
    }
  end
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
    if not f then return 1 end
    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, url, branch)
  logwrite('downloading '..url)

  -- clone the repo
  -- BUG: logwriting the git command doesn't actually log the output
  run('git -C '..opts.dl.dir..' clone '..url..' '..plugdir)
  run('git -C '..plugdir..' checkout -q '..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(i)
  local src = getsrc(plugins[i][1])
  local plugin = { -- plugin table spec
    id = plugins[i][1] or false,
    url = plugins[i]['url'] or (src['link'].."/"..src['repo']),
    file = plugins[i]['file'] or false,
    dir = plugins[i]['dir'] or 'scripts',
    pin = plugins[i]['pin'] or false,
    branch = plugins[i]['branch'] or false,
  }

  -- check if the user has defined a file for the current plugin
  if not plugin['file'] then
    logwrite('WARNING! File not configured for '..plugin[1])
    goto continue
  end
  -- skip install of pinned files
  if plugin['pin'] == true then goto continue end

  -- get the plugins tmp download dir
  local plugdir = opts.dl.dir..'/'..testforslash(src['repo']):gsub('.git', '')

  -- if no specified branch we use the default
  plugin['branch'] = plugin['branch'] or testforslash(
    run('git -C '..plugdir..' symbolic-ref refs/remotes/origin/HEAD')
  )

  -- check for multiple files
  if type(plugin['file']) == 'string' then
    plugin['file'] = {}
    table.insert(plugin['file'], plugins[i]['file'])
  end

  -- get the requested file(s)
  for j = 1, #plugin['file'] or 1 do
    -- get the file's dir
    local pluginfile = plugdir..'/'..plugin['file'][j]

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

    if fileexists(plugdir..'/') then
      -- if we need to update, update
      if checkupdates(plugdir) then
        logwrite(plugin['file'][j]..' is updating.')
        -- make sure we are on the main branch
        run('git -C '..plugdir..' checkout -q '..plugin['branch'])
        run('git -C '..plugdir..' pull') -- get the latest commits
      else
        logwrite(plugin['file'][j]..' is up to date!')
      end
    else
      clonegit(plugdir, plugin['url'], plugin['branch'])
    end

    -- copy the file contents over to the desired location
    cp(pluginfile, destfile)
  end
  ::continue::
end

local function initupdate()
  openlog()

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

  -- start the install process
  logwrite('Starting Download...')
  mp.osd_message('Downloading plugins!')

  -- start iterating through plugins
  for i = 1, tablelength(plugins) do
    local f = coroutine.create(function() startinstall(i) end)
    coroutine.resume(f)
  end

  -- 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

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

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