#!/bin/sh
#|-*- mode:lisp -*-|#
#|
exec ros -Q -- $0 "$@"
|#
(progn ;;init forms
  (ros:ensure-asdf)
  #+quicklisp
  (ql:quickload '(log4cl)
                :silent t))

(defpackage :ros.script.upload
  (:use :cl))
(in-package :ros.script.upload)


(defvar *current-dir*)


(define-condition unable-to-proceed (simple-error)
  ((message :initarg :message
            :reader get-message))
  (:report (lambda (condition stream)
             (format stream (get-message condition)))))


(define-condition subprocess-error-with-output (uiop::subprocess-error)
  ((stdout :initarg :stdout :reader subprocess-error-stdout)
   (stderr :initarg :stderr :reader subprocess-error-stderr))
  (:report (lambda (condition stream)
             (format stream "Subprocess ~@[~S~% ~]~@[with command ~S~% ~]exited with error~@[ code ~D ~]~@[ and this text at stderr:~% ~S~]"
                     (uiop:subprocess-error-process condition)
                     (uiop:subprocess-error-command condition)
                     (uiop:subprocess-error-code condition)
                     (subprocess-error-stderr condition)))))


(defun run (command &key (raise t))
  "Runs command and returns it's stdout stderr and code.

If there was an error, raises subprocess-error-with-output, but this
behaviour could be overriden by keyword argument ``:raise t``."
  
  (multiple-value-bind (stdout stderr code)
      (uiop:run-program command
                        :output '(:string :stripped t)
                        :error-output '(:string :stripped t)
                        :ignore-error-status t)
    
    (when (and raise
               (not (eql code 0)))
      (error 'subprocess-error-with-output
             :stdout stdout
             :stderr stderr
             :code code
             :command command))
    (values stdout stderr code)))


(defun gh-pages-repository-initialized-p (docs-dir)
  "Checks if repository for documentation already initialized"
  (uiop:directory-exists-p (uiop:merge-pathnames* #P".git/"
                                                  docs-dir)))


(defun git (&rest commands)
  "Calls git command in gh-pages repository."
  
  (uiop:with-current-directory (*current-dir*)
    (let ((command (apply #'concatenate 'string
                          "git "
                          commands)))
        
      (log:info "Running" command "in" *current-dir*)
      (run command))))


(defun git-repository-was-changed-p ()
  ;; if git status returns something, then repository have uncommitted changes
  (> (length (git "status --porcelain"))
     0))


(defun get-git-upstream ()
  ;; taken from http://stackoverflow.com/a/9753364/70293
  (let ((upstream (run "git rev-parse --abbrev-ref --symbolic-full-name @{u}" :raise nil)))
    (when (> (length upstream)
           0)
      (subseq upstream
              0
              (search "/" upstream)))))


(defun get-origin-to-push ()
  (let ((upstream (get-git-upstream)))

    (cond
      (upstream
       ;; If there is already some remote upstream, then use it
       (run (concatenate 'string "git remote get-url " upstream)))
      ;; If we are running inside github actions
      ((uiop:getenv "GITHUB_ACTIONS")
       (unless (uiop:getenv "GITHUB_TOKEN")
         (error 'unable-to-proceed
                :message "Please, provide GITHUB_TOKEN environment variable."))
       (format nil "https://~A:~A@github.com/~A"
               (uiop:getenv "GITHUB_ACTOR")
               (uiop:getenv "GITHUB_TOKEN")
               (uiop:getenv "GITHUB_REPOSITORY")))
      ;; otherwise make it from travis secret token and repo slug
      (t
       (let ((repo-slug (uiop:getenv "TRAVIS_REPO_SLUG"))
             (repo-token (uiop:getenv "GH_REPO_TOKEN")))

         (unless (and repo-slug repo-token)
           (error 'unable-to-proceed
                  :message "Current branch does not track any upstream and there is no TRAVIS_REPO_SLUG and GH_REPO_TOKEN env variables. Where to push gh-pages branch?"))

         (format nil "https://~A@github.com/~A"
                 repo-token
                 repo-slug))))))  


(defun push-gh-pages (docs-dir)
  (log:info "Pushing changes to gh-pages branch")

  (let ((*current-dir* docs-dir))
  
    (unless (gh-pages-repository-initialized-p docs-dir)
      (git "init")
    
      (git "remote add origin "
           (get-origin-to-push)))

    (git "add .")
  
    (cond
      ((git-repository-was-changed-p)
       (when (uiop:getenv "GITHUB_ACTIONS")
         (git "config --global user.name \"github-actions[bot]\"")
         (git "config --global user.email \"actions@github.com\""))
       (git "commit -m 'Update docs'")
    
       (git "push --force origin master:gh-pages"))
      ;; or
      (t (log:info "Everything is up to date.")))))


(defun push-local-changes ()
  "Some documentation builders, like MGL-PAX,
   can update README file as well. In this case, we need
   to push the file into the current branch of the repository."
  (let ((*current-dir* (probe-file #P"")))
    (cond
      ((git-repository-was-changed-p)
       
       (git "add -u")
       (when (uiop:getenv "GITHUB_ACTIONS")
         (log:info "Pushing changes to gh-pages branch")

         (git "config --global user.name \"github-actions[bot]\"")
         (git "config --global user.email \"actions@github.com\""))
       (git "commit -m 'Update docs'")
    
       (cond
         ((uiop:getenv "GITHUB_HEAD_REF")
          (git "push HEAD:"
               (uiop:getenv "GITHUB_HEAD_REF")))
         (t
          (git "push"))))
      ;; or
      (t (log:info "There is no local changes.")))))


(defun main (&rest argv)
  (log:info "Uploading documentation")

  (unless argv
    (log:error "Please, specify a directory with HTML docs.")
    (uiop:quit 1))

  (let ((docs-dir (uiop:parse-unix-namestring (first argv)
                                              :ensure-directory t)))

    (handler-bind ((error (lambda (condition)
                            (uiop:print-condition-backtrace condition :stream *error-output*)
                            (uiop:quit 1))))
      (unless (probe-file docs-dir)
        (log:error "Directory \"~A not found"
                   docs-dir)
        (uiop:quit 1))
      
      (uiop:with-output-file (s (uiop:merge-pathnames* #P".nojekyll"
                                                       docs-dir)
                                :if-exists :overwrite)
        (declare (ignorable s)))
      (push-gh-pages docs-dir)
      (push-local-changes))))

;;; vim: set ft=lisp lisp: