github.lua

-- Downloads GitHub repositories to your OpenComputers computer. --
--[[MIT License

(c) 2020 Ocawesome101

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]

local internet = require("component").internet or require("internet")
local shell = shell or require("shell")
local fs = fs or require("filesystem")

if not internet then
  return print("This program requires an internet card.")
end

local args, options = shell.parse(...) -- Open Kernel has argument parsing now! :D

if #args < 1 or options.help then
  print("Usage: github <user/repo> <branch> [destination]")
  print("  user/repo: The username and repository; for example, ocawesome101/open-kernel-2")
  print("  branch:    The desired repository branch. Defaults to master")
  return
end

local repo = args[1]
local branch = args[2] or "master"
local inst = (args[3] and shell.resolve(args[3])) or fs.name(repo)

fs.makeDirectory(package.libdir or "/usr/lib")
fs.makeDirectory(inst)

local function download(url, dest)
  checkArg(1, url, "string")
  checkArg(2, dest, "string")
  local handle, err
  if internet.request then
    handle, err = internet.request(url)
  else
    handle, err = internet.get(url)
  end
  if not handle then
    return print("github: WARNING: failed to download " .. url .. ": " .. err)
  end
  local fileData = ""
  repeat
    local chunk = handle.read(math.huge)
    fileData = fileData .. (chunk or "")
  until not chunk
  handle.close()
  local handle = io.open(dest, "w")
  handle:write(fileData)
  handle:close()
end

if not fs.exists((package.libdir or "/usr/lib") .. "/json.lua") then
  print("github: JSON library not found. Downloading....")
  download("https://raw.githubusercontent.com/rxi/json.lua/master/json.lua", (package.libdir or "/usr/lib") .. "/json.lua")
end

local json, err = require("json")
if not json then
  return print(err)
end

print("github: getting repository data")
local api, err
if internet.request then
  api, err = internet.request("https://api.github.com/repos/" .. repo .. "/git/trees/" .. branch .. "?recursive=1")
else
  api, err = internet.get("https://api.github.com/repos/" .. repo .. "/git/trees/" .. branch .. "?recursive=1")
end
if not api then
  return print(err)
end

local repoData = ""
repeat
  local chunk = api.read(math.huge)
  repoData = repoData .. (chunk or "")
until not chunk
api.close()

print("github: parsing repository data")
repoData = json.decode(repoData)

print("github: making directories")
for _,v in pairs(repoData.tree) do
  if v.type == "tree" then
    fs.makeDirectory(inst .. "/" .. v.path)
  end
end

print("github: downloading files from repository")
for _,v in pairs(repoData.tree) do
  if v.type == "blob" then
    local url = "https://raw.githubusercontent.com/" .. repo .. "/" .. branch .. "/" .. v.path
    download(url, inst .. "/" .. v.path)
  end
end