-- @@SHEBANG
-- -*- Lua -*-
-- gitano-auth
--
-- Git (with) Augmented network operations -- User authentication wrapper
--
-- 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 sp = require "luxio.subprocess"

-- @@GITANO_BIN_PATH
-- @@GITANO_SHARE_PATH

local repo_root, username, keytag = ...

gitano.config.repo_path(repo_root)

local cmdline = luxio.getenv "SSH_ORIGINAL_COMMAND" or ""

local transactionid = gitano.log.syslog.open()

if cmdline:match("^[ \t\n]*$") then
   gitano.log.fatal("No command provided, cannot continue")
end

local parsed_cmdline, warnings = gitano.util.parse_cmdline(cmdline)

local start_log_level = gitano.log.get_level()
-- Clamp level at info until we have checked if the caller
-- is an admin or not
gitano.log.cap_level(gitano.log.level.INFO)

if (#warnings > 0) then
   gitano.log.error("Warnings encountered parsing commandline.");
   gitano.log.warn("\t" ..  cmdline)
   gitano.log.warn("")
   gitano.log.warn("Parsed as:")
   for i = 1, #parsed_cmdline do
      gitano.log.warn(("  =[%2d]> %s"):format(i, parsed_cmdline[i]))
   end
   gitano.log.warn("\nWarnings were:")
   for i = 1, #warnings do
      gitano.log.warn(" * " .. warnings[i])
   end
   gitano.log.warn("")
   gitano.log.fatal("Game over, sorry\n")
end

-- Now load the administration data

local admin_repo = gall.repository.new((repo_root or "") .. "/gitano-admin.git")

if not admin_repo then
   gitano.log.fatal("Unable to locate administration repository.  Cannot continue");
end

local admin_head = admin_repo:get(admin_repo.HEAD)

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

local config, msg = gitano.config.parse(admin_head)

if not config then
   gitano.log.critical("Unable to parse administration repository.")
   gitano.log.critical("  * " .. (msg or "No error?"))
   gitano.log.fatal("Cannot continue")
end

-- Now, are we an admin?
if config.groups["gitano-admin"].filtered_members[username] then
   -- Yep, so blithely reset logging level
   gitano.log.set_level(start_log_level)
end

if not config.global.silent then
   -- Not silent, bump to chatty level automatically
   gitano.log.bump_level(gitano.log.level.CHAT)
end

local repo

-- Find the command


ip = string.match(luxio.getenv "SSH_CLIENT", "^[^ ]+") or ""

gitano.log.syslog.info("Client connected from", ip, "as", username,
                       "(" .. keytag .. ")", "Executing command:",
                       cmdline)

local cmd = gitano.command.get(parsed_cmdline[1])

if not cmd then
   gitano.log.fatal("Unknown command: " .. parsed_cmdline[1])
end

if cmd.takes_repo and #parsed_cmdline > 1 then
   -- Acquire the repository object for the target repo
   local msg
   repo, msg = gitano.repository.find(config, parsed_cmdline[2])
   if not repo then
      gitano.log.critical("Unable to locate repository.")
      gitano.log.critical("  * " .. (tostring(msg)))
      gitano.log.fatal("Cannot continue")
   end
   
   if repo.is_nascent then
      gitano.log.info("Repository " .. repo.name .. " is nascent")
   end
end

-- Validate the commandline, massaging it as necessary.

if not cmd.validate(config, repo, parsed_cmdline) then
   gitano.log.fatal("Validation of command line failed")
end

-- Construct our context ready for prep
local context = {
   source = "ssh",
   user = username,
   keytag = keytag,
}

local action, reason = cmd.prep(config, repo, parsed_cmdline, context)

if not action then
   gitano.log.crit(reason)
   gitano.log.fatal("Ruleset did not complete cleanly")
end

if action == "allow" then
   gitano.log.info(reason or "Ruleset permitted action")
else
   gitano.log.critical(reason)
   gitano.log.fatal("Ruleset denied action.  Sorry.")
end

gitano.log.debug("Welcome to " .. config.global.site_name)
gitano.log.debug("Running:")
for i = 1, #parsed_cmdline do
   gitano.log.debug(" => " .. parsed_cmdline[i])
end
gitano.log.debug("")
gitano.log.debug("On behalf of " .. username .. " using key " .. keytag)

-- Set up some useful environment variables

local env = {
   ["GITANO_ROOT"] = repo_root,
   ["GITANO_USER"] = username,
   ["GITANO_KEYTAG"] = keytag,
   ["GITANO_PROJECT"] = (repo or {}).name,
   ["GITANO_SOURCE"] = "ssh",
   ["GITANO_TRANSACTION_ID"] = transactionid,
}

local how, why = cmd.run(config, repo, parsed_cmdline, env)

if how ~= "exit" or why ~= 0 then
   gitano.log.critical("Error running sub-process:",
		       ("%s (%d)"):format(how, why))
   gitano.log.fatal("Unable to continue")
else
   gitano.log.syslog.info(cmdline, "completed successfully")
end

gitano.log.syslog.close()

return 0