github

local github = dofile("apis/github")

local selectedAction = select(1, ...)
local passed = { select(2, ...) }

local subcommands = {
	clone = {
		usage = "github clone <user>/<repo> [-b <branchname> | -t <tagname>] [<destination>] [-a <username>]",
		flags = {
			['-b'] = 'branch',
			['--branch'] = 'branch',
			['-t'] = 'tag',
			['--tag'] = 'tag',
			['-a'] = 'authed',
			['-auth'] = 'authed'
		}
	},
	auth = {
		usage = "github auth <user> [<api token> | -d ]",
		flags = {
			['-d'] = 'delete',
			['--delete'] = 'delete'
		}
	}
}

local action = subcommands[selectedAction]
if not action then
	for k, v in pairs(subcommands) do
		print(v.usage)
		print(" ")
	end
	return
end

-- make a bar of the form "[====>    ] 50%"
function progressbar(f)
	local left = "["
	local right = ("]%3d%%"):format(f * 100)

	local gap = select(1, term.getSize()) - #left - #right
	local at = math.floor(f * (gap + 1))
	for i = 1, gap do
		left = left .. (
			i < at and "=" or
			i > at and " " or
			           ">"
		)
	end
	return left .. right
end

-- get flag arguments
local function findFlag(arg)
	if arg.sub(1,1) == '-' then
		if not action.flags[arg] then
			return printError(('Unknown flag argument %s'):format(arg))
		end
	end
	return action.flags[arg]
end

local args = {}
local flags = {}
local lastFlagged = 0
for k, arg in pairs(passed) do
	if k ~= lastFlagged then
		local flagName = findFlag(arg)
		if flagName then
			flags[flagName] = passed[k + 1] or true
			lastFlagged = k + 1 or true
		else
			table.insert(args, arg)
		end
	end
end

if flags.branch and flags.tag then
	return printError('--branch and --tag cannot both be specified')
end


local function hasEnoughSpace(repoSize, freeSpace)
	-- The value reported by github underestimates the one reported by CC. This tries
	-- to guess when this matters.
	local sizeError = 0.2

	local function warnAndContinue()
		write("Repository may be too large to download, attempt anyway? [Y/n]: ")
		local validAnswers = { [''] = 'yes', y = 'yes', yes = 'yes', n = 'no', no = 'no' }
		local input = io.read()
		while not validAnswers[input:lower()] do
			print("Please type [y]es or [n]o")
			input = io.read()
		end
		return validAnswers[input:lower()] == 'yes'
	end

	if repoSize > freeSpace then
		return false
	elseif repoSize * (1 + sizeError) > freeSpace then
		return warnAndContinue()
	else
		return true
	end
end

local function sizeStr(bytes)
	local unit = 1024
	if bytes < unit then
		return ("%s byte(s)"):format(bytes)
	else
		local multi = 10^(1)
		local KiB = math.floor((bytes/unit) * multi + 0.5) / multi
		return ("%s KiB"):format(KiB)
	end
end

if action == subcommands.clone then
	-- parse input
	local repo, dest = args[1], args[2]
	local treeName = flags.branch or flags.tag or 'master'

	if not repo then return printError("No repo specified") end

	user, repo = repo:match('^(.-)/(.+)$')
	if not (user and repo) then return printError("Invalid repo name - should be user/repo") end

	dest = shell.resolve(dest or repo)

	local auth = nil

	if flags.authed then
		-- if no user is found auth should remain nil.
		auth = github.Auth.get(flags.authed)
	end

	if flags.authed and not auth then
		return printError("Unknown user! Add one with 'git auth'")
	elseif flags.authed and not auth:checkToken() then
		return printError("Invalid Token!")
	end

	-- get file listings
	local repo = github.repo(user, repo, auth)
	print("Discovering files...")
	local tree = repo:tree(treeName)

	-- download the files
	local totalSize = tree:getFullSize()
	local freeSpace = fs.getFreeSpace(dest)

	if not hasEnoughSpace(totalSize, freeSpace) then
		local errStr = "Repository is %s, but only %s are free on this computer. Aborting!"
		errStr = errStr:format(sizeStr(totalSize), sizeStr(freeSpace))
		return printError(errStr)
	end

	print("Downloading:")
	local size = 0
	tree:cloneTo(dest, function(item)
		-- called every time a download completes
		if getmetatable(item) == github.Blob then
			size = size + item.size
			term.clearLine()
			print("  "..item:fullPath())
			term.write(progressbar(size/totalSize))
			term.setCursorPos(1, select(2, term.getCursorPos()))
		end
	end)
	term.scroll(1)
	return
end

if action == subcommands.auth then
	local user, token = args[1], args[2]
	if not user then return printError("No user specified.") end

	if flags.delete then
		github.Auth.delete(user)
		print(('Deleted github token for user %s'):format(user))
	else
		if not token then return printError("No token specified.") end
		local auth = github.Auth.new('oauth', user, token)
		if auth:checkToken() then
			auth:save()
			print(('Saved github token for user %s'):format(auth.user))
		else
			return printError("Invalid token!")
		end
	end

	return
end

print(action.usage)