(* goaljobs
 * Copyright (C) 2013 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *)

(** {1 Goaljobs library API} *)

(** {2 Target and require} *)

val target : bool -> unit
  (** [target] {i condition} defines the target condition that {b will}
      be met once the current goal has run.

      You can think of the target as a promise or contract that you
      make, which is met by running the rest of the goal.

      Goaljobs is much more flexible than [make].  In [make] only a
      single type of target is possible.  The following are roughly
      equivalent:

      {v
      foo.o: foo.c
        ...
      v}

      {v
      let goal compiled () =
        target (more_recent ["foo.o"] ["foo.c"]);
        require (file_exists "foo.c");
        ...
      v}

      Targets in goaljobs can be any arbitrary expression.  For
      example, it can access network resources or test URLs.

      Almost every goal should have one target, which should
      accurately state the outcome once the goal has been run.

      It is possible to have no target.  This means the goal
      always runs (like using "force" in make).

      You should not have multiple targets in a single goal.  They
      won't work the way you expect, and future versions of goaljobs
      will likely stop you from doing this.

      Normally you put the target(s) early on in the goal, before any
      running code and before any [require]s.  This is not a
      hard-and-fast rule and it is not enforced, but doing it will
      ensure the goal runs most efficiently since if the target is met
      already then the rest of the goal doesn't run. *)

val target_all : bool list -> unit
  (** [target_all [t1; t2; ...]] is the same as writing
      [target (t1 && t2 && ...)] *)

val target_exists : bool list -> unit
  (** [target_exists [t1; t2; ...]] is the same as writing
      [target (t1 || t2 || ...)] *)

val require : string -> (unit -> unit) -> unit
  (** [require] {i goal} defines the requirements of this goal, that
      is, other goals that have to be met before the rest of the
      goal is able to run.

      In terms of [make], [require]s are roughly equivalent to the
      right hand side after the [:], but in goaljobs the requirements
      can be much richer than simply "that file must exist".

      Some very simple goals don't need any [require]s.  You can
      have as many [require]s as you need in a goal, and you can
      use a loop or make them conditional if you want.

      Unlike [make], the requirements of a goal can be
      placed anywhere within the goal, as long as you put them
      before they are needed. *)

(** {2 Periodic jobs} *)

(* This is what lets you write '30 minutes' etc: *)
type period_t = Seconds | Days | Months | Years
val seconds : int * period_t
val sec : int * period_t
val secs : int * period_t
val second : int * period_t
val minutes : int * period_t
val min : int * period_t
val mins : int * period_t
val minute : int * period_t
val hours : int * period_t
val hour : int * period_t
val days : int * period_t
val day : int * period_t
val weeks : int * period_t
val week : int * period_t
val months : int * period_t
val month : int * period_t
val years : int * period_t
val year : int * period_t

val every : ?name:string -> int -> int * period_t -> (unit -> unit) -> unit
  (** [every N (seconds|minutes|hours|days|weeks|months|years) f]
      runs the function [f] periodically.

      The optional [~name] parameter can be used to name the job
      (for debugging). *)

(** {2 File and URL testing}

    Various functions to test the existence of files, URLs.
*)

val file_exists : string -> bool
  (** Return true if the named file exists.

      This function also exists as a goal.  Writing:
      {v require (file_exists "somefile"); v}
      will die unless ["somefile"] exists. *)

val directory_exists : string -> bool
  (** Return true if the named directory exists.

      There is also a goal version of this function. *)

val file_newer_than : string -> string -> bool
  (** [file_newer_than file_a file_b] returns true if [file_a] is
      newer than [file_b].  Note that if [file_a] does not exist, it
      returns false.  If [file_b] does not exist, it is an error.

      There is also a goal version of this function. *)

val more_recent : string list -> string list -> bool
  (** [more_recent objects sources] expresses the [make] relationship:

      {v object(s) ...: source(s) ... v}

      in a convenient way:

      {v
      let goal built objects sources =
        target (more_recent objects sources);
        ... code to rebuild ...
      v}

      It is roughly equivalent to checking that all the object files
      exist and are newer than all of the source files.

      Note that both parameters are lists (since in [make] you can
      have a list of source files and a list of object files).  If you
      don't want a list, pass a single-element list containing the
      single the object/source file.

      There is also a goal version of this function. *)

val url_exists : string -> bool
  (** The URL is tested to see if it exists.

      There is also a goal version of this function. *)

val file_contains_string : string -> string -> bool
  (** [file_contains_string filename str] checks if the named file
      contains the given substring [str].

      There is also a goal version of this function. *)

val url_contains_string : string -> string -> bool
  (** [url_contains_string url str] downloads the URL and checks
      whether the content contains the given substring [str].

      There is also a goal version of this function. *)

val (//) : string -> string -> string
  (** Concatenate two paths. *)

val quote : string -> string
  (** Quote the string to make it safe to pass directly to the shell. *)

(** {2 Shell} *)

val sh : ?tmpdir:bool -> ('a, unit, string, unit) format4 -> 'a
  (** Run the command(s).

      The command runs in a newly created temporary directory (which
      is deleted after the command exits), {i unless} you use
      [~tmpdir:false]. *)

val shout : ?tmpdir:bool -> ('a, unit, string, string) format4 -> 'a
  (** Run the command(s).

      Anything printed on stdout is returned as a string.
      The trailing [\n] character, if any, is not returned.

      The command runs in a newly created temporary directory (which
      is deleted after the command exits), {i unless} you use
      [~tmpdir:false]. *)

val shlines : ?tmpdir:bool -> ('a, unit, string, string list) format4 -> 'a
  (** Run the command(s).

      Any lines printed to stdout is returned as a list of strings.
      Trailing [\n] characters are not returned.

      The command runs in a newly created temporary directory (which
      is deleted after the command exits), {i unless} you use
      [~tmpdir:false]. *)

val shell : string ref
  (** Set this variable to override the default shell ([/bin/sh]). *)

(** {2 String functions}

    Most string functions are provided by the OCaml standard
    library (see the module [String]).  For convenience some
    extra functions are provided here. *)

(*
val replace_substring : string -> string -> string -> string
  (** [replace_substring patt repl string] replaces all occurrences
      of [patt] with [repl] in [string]. *)
*)

val change_file_extension : string -> string -> string
  (** [change_file_extension ext filename] changes the file extension
      of [filename] to [.ext].  For example
      [change_file_extension "o" "main.c"] returns ["main.o"].
      If the original filename has no extension, this function
      adds the extension. *)

(*
val filter_file_extension : string -> string list -> string
  (** [filter_file_extension ext filenames] returns only those
      filenames in the list which have the given file extension.
      For example [filter_file_extension "o" ["foo.c"; "bar.o"]]
      would return [["bar.o"]] (a single element list). *)
*)

(** {2 Memory (persistent key/value storage)} *)

val memory_exists : string -> bool
  (** [memory_exists key] checks that the named [key] exists in
      the Memory.  It doesn't matter what value it has.

      This is also available as a goal, so you can write
      [require (memory_exists key)] *)

val memory_set : string -> string -> unit
  (** Set [key] to [value] in the Memory. *)

val memory_get : string -> string option
  (** Return the current value of [key] in the Memory.  Returns [None]
      if the key has never been set or was deleted. *)

val memory_delete : string -> unit
  (** Delete the [key].  If the key doesn't exist, has no effect. *)

(** {2 Publishing goals} *)

val publish : string -> (string list -> unit) -> unit
  (** Publish the named goal.

      Use this function as in this example:

      {v
      let goal compiled program sources =
        ... stuff for building the program from sources ...

      let () = publish "compiled" (
        fun args ->
          let program = List.hd args in
          let sources = List.tl args in
          require (compiled program sources)
      )
      v}

      This could be used as follows:

      {v ./script compiled program main.c utils.c v}

      You will notice you have to write a bit of OCaml code to
      map the string arguments from the command line on to the
      goal arguments.  In the example it means taking the first
      string argument as the program name, and the rest of the
      string arguments as the source filenames.  This is also
      the place to perform string to int conversion, checks, and
      so on (remember that OCaml is strongly typed). *)

(** {2 Logging script output} *)

val log_program_output : unit -> string
  (** [log_program_output] should be called at most once, usually at
      the top-level of the script.  It creates a temporary file
      and redirects stdout and stderr into this file (they are still
      sent to the ordinary output, so it acts like [tee]).  The
      filename of the temporary file is returned. *)

(** {2 Sending email} *)

val mailto : ?from:string -> subject:string -> ?attach:string list-> string -> unit
  (** Send email.

      Optional [?from] is the sender email address.

      Required [~subject] is the subject line.

      Optional [?attach] is a list of attachments (filenames).

      The bare argument is the destination email address. *)

(**/**)

(* Goal versions of some common functions.  You are using these
 * versions when you write something like:
 *   require (file_exists "foo");
 * They work the same way as the regular function, except they die
 * if the predicate returns false.
 *)
val goal_file_exists : string -> unit
val goal_directory_exists : string -> unit
val goal_file_newer_than : string -> string -> unit
val goal_more_recent : string list -> string list -> unit
val goal_url_exists : string -> unit
val goal_file_contains_string : string -> string -> unit
val goal_url_contains_string : string -> string -> unit
val goal_memory_exists : string -> unit

(* A single call to this function is added by the 'goaljobs' script.
 * It is responsible for parsing the command line and so on.
 *)
val init : unit -> unit

(* Export this so the macros can catch these exceptions. *)
type goal_result_t = Goal_OK | Goal_failed of string
exception Goal_result of goal_result_t

(* Called to print debug message when we enter or leave a goal. *)
val _enter_goal : string -> unit
val _leave_goal : string -> unit