// file      : build2/test/script/script -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef BUILD2_TEST_SCRIPT_SCRIPT
#define BUILD2_TEST_SCRIPT_SCRIPT

#include <set>

#include <build2/types>
#include <build2/utility>

#include <build2/variable>

#include <build2/test/target>

#include <build2/test/script/token> // replay_tokens

namespace build2
{
  class target;

  namespace test
  {
    namespace script
    {
      class parser; // Required by VC for 'friend class parser' declaration.

      // Pre-parse representation.
      //

      enum class line_type
      {
        var,
        cmd,
        cmd_if,
        cmd_ifn,
        cmd_elif,
        cmd_elifn,
        cmd_else,
        cmd_end
      };

      ostream&
      operator<< (ostream&, line_type);

      struct line
      {
        line_type type;
        replay_tokens tokens;

        union
        {
          const variable* var; // Pre-entered for line_type::var.
        };
      };

      // Most of the time we will have just one line (test command).
      //
      using lines = small_vector<line, 1>;

      // Parse object model.
      //

      // redirect
      //
      enum class redirect_type
      {
        none,
        pass,
        null,
        merge,
        here_string,
        here_document,
        file
      };

      struct redirect
      {
        redirect_type type;

        struct doc_type
        {
          string doc; // Note: includes trailing newline, if required.
          string end;
        };

        struct file_type
        {
          using path_type = build2::path;
          path_type path;
          bool append = false;
        };

        union
        {
          int       fd;  // Merge-to descriptor.
          string    str; // Note: includes trailing newline, if required.
          doc_type  doc;
          file_type file;
        };

        explicit
        redirect (redirect_type = redirect_type::none);

        redirect (redirect&&);
        redirect (const redirect&);
        redirect& operator= (redirect&&);
        redirect& operator= (const redirect&);

        ~redirect ();
      };

      // cleanup
      //
      enum class cleanup_type
      {
        always, // &foo  - cleanup, fail if does not exist.
        maybe,  // &?foo - cleanup, ignore if does not exist.
        never   // &!foo - don’t cleanup, ignore if doesn’t exist.
      };

      // File or directory to be automatically cleaned up at the end of the
      // scope. If the path ends with a trailing slash, then it is assumed to
      // be a directory, otherwise -- a file. A directory that is about to be
      // cleaned up must be empty.
      //
      // The last component in the path may contain a wildcard that have the
      // following semantics:
      //
      // dir/*   - remove all immediate files
      // dir/*/  - remove all immediate sub-directories (must be empty)
      // dir/**  - remove all files recursively
      // dir/**/ - remove all sub-directories recursively (must be empty)
      // dir/*** - remove directory dir with all files and sub-directories
      //           recursively
      //
      struct cleanup
      {
        cleanup_type type;
        build2::path path;
      };
      using cleanups = vector<cleanup>;

      // command_exit
      //
      enum class exit_comparison {eq, ne};

      struct command_exit
      {
        // C/C++ don't apply constraints on program exit code other than it
        // being of type int.
        //
        // POSIX specifies that only the least significant 8 bits shall be
        // available from wait() and waitpid(); the full value shall be
        // available from waitid() (read more at _Exit, _exit Open Group
        // spec).
        //
        // While the Linux man page for waitid() doesn't mention any
        // deviations from the standard, the FreeBSD implementation (as of
        // version 11.0) only returns 8 bits like the other wait*() calls.
        //
        // Windows supports 32-bit exit codes.
        //
        // Note that in shells some exit values can have special meaning so
        // using them can be a source of confusion. For bash values in the
        // [126, 255] range are such a special ones (see Appendix E, "Exit
        // Codes With Special Meanings" in the Advanced Bash-Scripting Guide).
        //
        exit_comparison comparison;
        uint8_t status;
      };

      // command
      //
      struct command
      {
        path program;
        strings arguments;

        redirect in;
        redirect out;
        redirect err;

        script::cleanups cleanups;

        command_exit exit {exit_comparison::eq, 0};
      };

      enum class command_to_stream: uint16_t
      {
        header   = 0x01,
        here_doc = 0x02,              // Note: printed on a new line.
        all      = header | here_doc
      };

      void
      to_stream (ostream&, const command&, command_to_stream);

      ostream&
      operator<< (ostream&, const command&);

      // command_pipe
      //
      using command_pipe = vector<command>;

      void
      to_stream (ostream&, const command_pipe&, command_to_stream);

      ostream&
      operator<< (ostream&, const command_pipe&);

      // command_expr
      //
      enum class expr_operator {log_or, log_and};

      struct expr_term
      {
        expr_operator op; // Ignored for the first term.
        command_pipe pipe;
      };

      using command_expr = vector<expr_term>;

      void
      to_stream (ostream&, const command_expr&, command_to_stream);

      ostream&
      operator<< (ostream&, const command_expr&);

      // description
      //
      struct description
      {
        string id;
        string summary;
        string details;

        bool
        empty () const
        {
          return id.empty () && summary.empty () && details.empty ();
        }
      };

      // scope
      //
      class script;

      class scope
      {
      public:
        scope* const parent; // NULL for the root (script) scope.
        script* const root;  // Self for the root (script) scope.

        // The chain of if-else scope alternatives. See also if_cond_ below.
        //
        unique_ptr<scope> if_chain;

        // Note that if we pass the variable name as a string, then it will
        // be looked up in the wrong pool.
        //
        variable_map vars;

        const path& id_path;     // Id path ($@, relative in POSIX form).
        const dir_path& wd_path; // Working dir ($~, absolute and normalized).

        optional<description> desc;

        test::script::cleanups cleanups;

        // Variables.
        //
      public:
        // Lookup the variable starting from this scope, continuing with outer
        // scopes, then the target being tested, then the testscript target,
        // and then outer buildfile scopes (including testscript-type/pattern
        // specific).
        //
        lookup
        find (const variable&) const;

        // As above but only look for buildfile variables.
        //
        lookup
        find_in_buildfile (const string&) const;

        // Return a value suitable for assignment. If the variable does not
        // exist in this scope's map, then a new one with the NULL value is
        // added and returned. Otherwise the existing value is returned.
        //
        value&
        assign (const variable& var) {return vars.assign (var);}

        // Return a value suitable for append/prepend. If the variable does
        // not exist in this scope's map, then outer scopes are searched for
        // the same variable. If found then a new variable with the found
        // value is added to this scope and returned. Otherwise this function
        // proceeds as assign() above.
        //
        value&
        append (const variable&);

        // Reset special $*, $N variables based on the test.* values.
        //
        void
        reset_special ();

        // Cleanup.
        //
      public:
        // Register a cleanup. If the cleanup is explicit, then override the
        // cleanup type if this path is already registered. Ignore implicit
        // registration of a path outside script working directory.
        //
        void
        clean (cleanup, bool implicit);

      public:
        virtual
        ~scope () = default;

      protected:
        scope (const string& id, scope* parent);

        // Pre-parse data.
        //
      public:
        virtual bool
        empty () const = 0;

      protected:
        friend class parser;

        location start_loc_;
        location end_loc_;

        optional<line> if_cond_;
      };

      // group
      //
      class group: public scope
      {
      public:
        vector<unique_ptr<scope>> scopes;

      public:
        group (const string& id, group& p): scope (id, &p) {}

      protected:
        group (const string& id): scope (id, nullptr) {} // For root.

        // Pre-parse data.
        //
      public:
        virtual bool
        empty () const override
        {
          return
            setup_.empty () &&
            tdown_.empty () &&
            find_if (scopes.begin (), scopes.end (),
                     [] (const unique_ptr<scope>& s)
                     {
                       return !s->empty ();
                     }) == scopes.end ();
        }

      private:
        friend class parser;

        lines setup_;
        lines tdown_;
      };

      // test
      //
      class test: public scope
      {
      public:
        test (const string& id, group& p): scope (id, &p) {}

        // Pre-parse data.
        //
      public:
        virtual bool
        empty () const override
        {
          return tests_.empty ();
        }

      private:
        friend class parser;

        lines tests_;
      };

      // script
      //
      class script_base // Make sure certain things are initialized early.
      {
      protected:
        script_base ();

      public:
        variable_pool var_pool;

        const variable& test_var; // test
        const variable& opts_var; // test.options
        const variable& args_var; // test.arguments

        const variable& wd_var;       // $~
        const variable& id_var;       // $@
        const variable& cmd_var;      // $*
        const variable* cmdN_var[10]; // $N
      };

      class script: public script_base, public group
      {
      public:
        script (target& test_target,
                testscript& script_target,
                const dir_path& root_wd);

        script (script&&) = delete;
        script (const script&) = delete;
        script& operator= (script&&) = delete;
        script& operator= (const script&) = delete;

      public:
        target& test_target;       // Target we are testing.
        testscript& script_target; // Target of the testscript file.

        // Pre-parse data.
        //
      private:
        friend class parser;

        // Testscript file paths. Specifically, replay_token::file points to
        // these paths.
        //
        std::set<path> paths_;
      };
    }
  }
}

#include <build2/test/script/script.ixx>

#endif // BUILD2_TEST_SCRIPT_SCRIPT