-- @@SHEBANG
-- -*- Lua -*-
-- gitano-setup
--
-- Git (with) Augmented network operations -- Instance setup tool
--
-- Copyright 2012 Daniel Silverstone <dsilvers@digital-scurf.org>
--
--

-- @@GITANO_LUA_PATH

local gitano = require "gitano"
local gall = require "gall"
local luxio = require "luxio"
local sio = require "luxio.simple"
local clod = require "clod"

-- @@GITANO_BIN_PATH
-- @@GITANO_SHARE_PATH

local possible_answers = {...}

if possible_answers[1] == "--help" or
   possible_answers[1] == "-h" or
   possible_answers[1] == "--usage" then
   sio.stderr:write([[
usage: gitano-setup [<answers-file>...]

This tool creates the basic repository setup for a Gitano instance.

This is an interactive tool where if it has any questions for you, it will
visit each answers file in turn until it finds the answer.  This means
that for automation purposes you can specify multiple answers files with
the earlier ones overriding the later ones.

In summary, the behaviour is as follows:

The repository root is created if it does not exist, and a gitano-admin.git
repository is created within it.  Said repository is populated with the
example administration repository rules and an admin user and group.
]])
   return 1
end		      

local conf = clod.parse("")

gitano.log.set_prefix("gitano-setup")
gitano.log.bump_level(gitano.log.level.CHAT)

for i = #possible_answers, 1, -1 do
   gitano.log.debug("Parsing answers file:", possible_answers[1])
   local one_conf = assert(clod.parse(assert(io.open(possible_answers[1], "r")):read "*a",
				      "@" .. possible_answers[1]))
   gitano.log.debug("Combining answers into conf...")
   for k,v in one_conf:each() do
      gitano.log.ddebug(tostring(k) .. " = " .. tostring(v))
      conf.settings[k] = v
   end
end

gitano.log.chat("Welcome to the Gitano setup process")

function get(key)
   return conf.settings[key]
end

function ask_for(key, prompt, default)
   local cur_value = conf.settings[key] or default
   gitano.log.ddebug("ask_for(", tostring(key), ", ", tostring(prompt), ", ",
		     tostring(default), ") [", tostring(cur_value), " ]")
   if not conf.settings["setup.batch"] then
      local default_str = (cur_value == nil) and "" or  " [" .. tostring(cur_value) .. "]"
      sio.stdout:write((prompt or key) .. default_str .. ": ")
      local new_value = sio.stdin:read("*l")
      if new_value and new_value ~= "" then
	 cur_value = new_value
      end
   end
   gitano.log.info("Setting:", key, "is", tostring(cur_value))
   conf.settings[key] = cur_value
   return cur_value
end

function look_for_path(path)
   local ret, stat = luxio.stat(path)
   if ret ~= 0 then
      return false, path .. ": " .. luxio.strerror(stat)
   end
   if luxio.S_ISDIR(stat.mode) == 0 then
      return false, path .. ": not a directory"
   end
   return true
end

function validate_path(path)
   local ok, msg = look_for_path(path)
   if not ok then
      error(msg, 2)
   end
end

function file_exists(path)
   local fh = io.open(tostring(path), "r")
   if not fh then
      return false
   end
   fh:close()
   return true
end

function validate_name(n)
   if not n:match("^[a-z_][a-z0-9_%-]*$") then
      error("Invalid name: " .. n, 2)
   end
end

if conf.settings["setup.batch"] then
   gitano.log.info("Batch mode engaged")
else
   gitano.log.info("Interactive mode engaged")
end

gitano.log.chat("Step 1: Determine everything")

validate_path(ask_for("paths.home", "Home directory for new Gitano user",
		      os.getenv "HOME"))

ask_for("paths.ssh", "SSH directory for new Gitano user",
	get("paths.home") .. "/.ssh")

local pubkey_path
if look_for_path(get("paths.ssh")) then
   -- Try and find a pubkey to use
   for _, ktype in ipairs { "rsa", "ecdsa" } do
      local pk = get("paths.ssh") .. "/id_" .. ktype .. ".pub"
      if file_exists(pk) then
	 pubkey_path = pk
	 break
      end
   end
end

assert(file_exists(ask_for("paths.pubkey", "Public key file for admin user",
			   pubkey_path)),
       "Cannot find public key")

ask_for("paths.repos", "Repository path for new Gitano instance",
	get("paths.home") .. "/repos")

validate_name(ask_for("admin.username", "User name for admin user",
		      "admin"))
ask_for("admin.realname", "Real name for admin user",
	"Administrator")

ask_for("admin.email", "Email address for admin user",
	"admin@administrator.local")

validate_name(ask_for("admin.keyname", "Key name for administrator",
		      "default"))

ask_for("site.name", "Site name", "a random Gitano instance")
ask_for("log.prefix", "Site log prefix", "gitano")

gitano.log.chat("Step 2: Gather required content")

gitano.log.info("=> Prepare site config")
local completely_flat = {}
local site_conf = clod.parse("")
site_conf.settings["site_name"] = get "site.name"
site_conf.settings["log.prefix"] = get "log.prefix"
completely_flat["site.conf"] = site_conf:serialise()

-- Acquire the contents of the skeleton gitano-admin repository
gitano.log.info("=> Acquire skeleton gitano-admin")
local skel_path = gitano.config.share_path() .. "/skel/gitano-admin"
local skel = assert(sio.opendir(skel_path))
local function acquire(dir, base, path)
   gitano.log.ddebug("Acquire skeleton in:", path)
   for ent in dir:iterate() do
      if not (ent == "." or ent == "..") then
	 local entpath = path .. "/" .. ent
	 local treeent = base .. ent
	 if look_for_path(entpath) then
	    local subdir = assert(sio.opendir(entpath))
	    acquire(subdir, treeent .. "/", entpath)
	    subdir:close()
	 else
	    local fh = io.open(entpath, "r")
	    completely_flat[treeent] = fh:read "*a"
	    fh:close()
	 end
      end
   end
end
acquire(skel, "", skel_path)
skel:close()

-- Now build the user files
gitano.log.info("=> Preparing administration user (" .. get("admin.username") .. ")")
local userpath = "users/" .. get("admin.username") .. "/user.conf"
local keypath = "users/" .. get("admin.username") .. "/" .. get("admin.keyname") .. ".key"
local userconf = clod.parse("")
userconf.settings.real_name = get("admin.realname")
userconf.settings.email_address = get("admin.email")
completely_flat[userpath] = userconf:serialise()
completely_flat[keypath] = assert(sio.open(get("paths.pubkey"), "r")):read "*a"

-- And now the gitano-admin group
gitano.log.info("=> Preparing gitano-admin group")
local groupconf = clod.parse("")
groupconf.settings.description = "Gitano Instance Administrators"
groupconf.settings["members.*"] = get("admin.username")
completely_flat["groups/gitano-admin.conf"] = groupconf:serialise()

gitano.log.chat("Step 3: Write out paths and gitano-admin.git")

gitano.log.info("=> Make paths")
gitano.util.mkdir_p(get("paths.repos") .. "/.graveyard")
gitano.util.mkdir_p(get "paths.ssh")
assert(sio.chmod(get "paths.ssh", "0700"))
gitano.config.repo_path(get "paths.repos")

gitano.log.info("=> Prepare repository")

local raw_repo = assert(gall.repository.create(get("paths.repos") .. 
						     "/gitano-admin.git"))

gitano.log.info("=> Create a flattened tree")
for k, v in pairs(completely_flat) do
   gitano.log.debug("  => Make object", k)
   completely_flat[k] = gall.object.create(raw_repo, "blob", v)
end

gitano.log.info("=> Commit that tree")
local real_tree = assert(gall.tree.create(raw_repo, completely_flat))

local person = {
   realname = get "admin.realname",
   email = get "admin.email",
}
local commit_data = {
   author = person,
   committer = person,
   tree = real_tree,
   message = "Initial setup",
}

local commit_obj = assert(gall.commit.create(raw_repo, commit_data))

gitano.log.info("=> Attach that commit to master")

assert(raw_repo:update_ref("refs/heads/master", commit_obj.sha,
			   "Create initial master ref"))

gitano.log.info("=> Ensure we can parse our resultant admin repository")

local admin_head = raw_repo:get(raw_repo.HEAD)

if not admin_head then
   gitano.log.fatal("Unable to find the HEAD of the administration repository.  Cannot continue");
end

local config = assert(gitano.config.parse(admin_head))
-- Restore the prefix for our logging
gitano.log.set_prefix("gitano-setup")
-- Verify that our user exists

assert(config.users[get "admin.username"], "Could not find user")
assert(config.groups["gitano-admin"].filtered_members[get "admin.username"],
       "User was not a gitano-admin")

gitano.log.info("=> Change the admin ref for gitano-admin.git")
config.repo:set_description("Instance administration repository")
config.repo:set_owner(get "admin.username")

gitano.log.info("=> Write the SSH authorized_keys file out")

gitano.config.writessh(config, get("paths.ssh") .. "/authorized_keys")
assert(sio.chmod(get("paths.ssh") .. "/authorized_keys", "0600"))