//
// aegis - project change supervisor
// Copyright (C) 1991-1999, 2001-2009, 2011-2014 Peter Miller
// Copyright (C) 2006-2009 Walter Franzini
//
// 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 3 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, see <http://www.gnu.org/licenses/>.
//

#include <common/ac/assert.h>
#include <common/ac/stdio.h>
#include <common/ac/stdlib.h>
#include <common/ac/unistd.h>
#include <common/ac/libintl.h>

#include <common/progname.h>
#include <common/quit.h>
#include <common/sizeof.h>
#include <common/str_list.h>
#include <common/trace.h>
#include <libaegis/ael/change/files.h>
#include <libaegis/arglex/change.h>
#include <libaegis/arglex/project.h>
#include <libaegis/arglex2.h>
#include <libaegis/change/branch.h>
#include <libaegis/change/file.h>
#include <libaegis/change/identifier.h>
#include <libaegis/commit.h>
#include <libaegis/file.h>
#include <libaegis/help.h>
#include <libaegis/lock.h>
#include <libaegis/log.h>
#include <libaegis/os.h>
#include <libaegis/project.h>
#include <libaegis/project/file.h>
#include <libaegis/search_path/base_get.h>
#include <libaegis/sub.h>
#include <libaegis/undo.h>
#include <libaegis/user.h>

#include <aegis/aecpu.h>


static void
copy_file_undo_usage(void)
{
    const char      *progname;

    progname = progname_get();
    fprintf
    (
        stderr,
        "usage: %s -CoPy_file_Undo [ <option>... ] <filename>...\n",
        progname
    );
    fprintf
    (
        stderr,
        "       %s -CoPy_file_Undo -List [ <option>... ]\n",
        progname
    );
    fprintf(stderr, "       %s -CoPy_file_Undo -Help\n", progname);
    quit(1);
}


static void
copy_file_undo_help(void)
{
    help("aecpu", copy_file_undo_usage);
}


static void
copy_file_undo_list(void)
{
    trace(("copy_file_undo_list()\n{\n"));
    arglex();
    change_identifier cid;
    cid.command_line_parse_rest(copy_file_undo_usage);
    list_change_files(cid, 0);
    trace(("}\n"));
}


static void
copy_file_undo_main(void)
{
    sub_context_ty  *scp;
    size_t          j;
    size_t          k;
    string_ty       *s1;
    string_ty       *s2;
    string_ty       *project_name;
    project      *pp;
    long            change_number;
    change::pointer cp;
    log_style_ty    log_style;
    user_ty::pointer up;
    int             config_seen;
    int             number_of_errors;
    int             tests_uncopied;

    trace(("copy_file_undo_main()\n{\n"));
    arglex();
    string_list_ty wl;
    project_name = 0;
    change_number = 0;
    log_style = log_style_append_default;
    bool unchanged = false;
    bool uninsulate = false;
    while (arglex_token != arglex_token_eoln)
    {
        switch (arglex_token)
        {
        default:
            generic_argument(copy_file_undo_usage);
            continue;

        case arglex_token_directory:
            if (arglex() != arglex_token_string)
                option_needs_dir(arglex_token_directory, copy_file_undo_usage);
            goto get_file_names;

        case arglex_token_file:
            if (arglex() != arglex_token_string)
                option_needs_files(arglex_token_file, copy_file_undo_usage);
            // fall through...

        case arglex_token_string:
            get_file_names:
            s2 = str_from_c(arglex_value.alv_string);
            wl.push_back(s2);
            str_free(s2);
            break;

        case arglex_token_keep:
        case arglex_token_interactive:
        case arglex_token_keep_not:
            user_ty::delete_file_argument(copy_file_undo_usage);
            break;

        case arglex_token_change:
            arglex();
            // fall through...

        case arglex_token_number:
            arglex_parse_change
            (
                &project_name,
                &change_number,
                copy_file_undo_usage
            );
            continue;

        case arglex_token_project:
            arglex();
            arglex_parse_project(&project_name, copy_file_undo_usage);
            continue;

        case arglex_token_nolog:
            if (log_style == log_style_none)
                duplicate_option(copy_file_undo_usage);
            log_style = log_style_none;
            break;

        case arglex_token_unchanged:
            if (unchanged)
                duplicate_option(copy_file_undo_usage);
            unchanged = true;
            break;

        case arglex_token_wait:
        case arglex_token_wait_not:
            user_ty::lock_wait_argument(copy_file_undo_usage);
            break;

        case arglex_token_base_relative:
        case arglex_token_current_relative:
            user_ty::relative_filename_preference_argument
            (
                copy_file_undo_usage
            );
            break;

        case arglex_token_symbolic_links:
        case arglex_token_symbolic_links_not:
            user_ty::symlink_pref_argument(copy_file_undo_usage);
            break;

        case arglex_token_read_only:
            if (uninsulate)
                duplicate_option(copy_file_undo_usage);
            uninsulate = true;
            break;
        }
        arglex();
    }
    if (!uninsulate && !unchanged && !wl.size())
        fatal_intl(0, i18n("no file names"));

    //
    // locate project data
    //
    if (!project_name)
    {
        nstring n = user_ty::create()->default_project();
        project_name = str_copy(n.get_ref());
    }
    pp = project_alloc(project_name);
    str_free(project_name);
    pp->bind_existing();

    //
    // locate user data
    //
    up = user_ty::create();

    //
    // locate change data
    //
    if (!change_number)
        change_number = up->default_change(pp);
    cp = change::create(pp, change_number);
    cp->bind_existing();

    //
    // lock the change file
    //
    change_cstate_lock_prepare(cp);
    lock_take();

    log_open(cp->logfile_get(), up, log_style);

    //
    // It is an error if the change is not in the in_development state.
    // It is an error if the change is not assigned to the current user.
    //
    if (!cp->is_being_developed())
        change_fatal(cp, 0, i18n("bad cp undo state"));
    if (cp->is_a_branch())
        change_fatal(cp, 0, i18n("bad cp undo branch"));
    if (nstring(cp->developer_name()) != up->name())
        change_fatal(cp, 0, i18n("not developer"));

    //
    // If no files were named and the -insulate or -unchanged options
    // were used, add all of the modified files in the change.
    // It is an error if there are none.
    //
    if (!wl.size())
        wl.push_back(cp->development_directory_get(1));

    //
    // resolve the path of each file
    // 1.   the absolute path of the file name is obtained
    // 2.   if the file is inside the development directory, ok
    // 3.   if the file is inside the baseline, ok
    // 4.   if neither, error
    //
    config_seen = 0;
    nstring_list search_path;
    cp->search_path_get(search_path, true);

    //
    // Find the base for relative filenames.
    //
    nstring base = search_path_base_get(search_path, up);

    string_list_ty wl2;
    number_of_errors = 0;
    for (j = 0; j < wl.size(); ++j)
    {
        string_list_ty  wl_in;

        s1 = wl[j];
        if (s1->str_text[0] == '/')
            s2 = str_copy(s1);
        else
            s2 = os_path_join(base.get_ref(), s1);
        up->become_begin();
        s1 = os_pathname(s2, 1);
        up->become_end();
        str_free(s2);
        s2 = 0;
        for (k = 0; k < search_path.size(); ++k)
        {
            s2 = os_below_dir(search_path[k].get_ref(), s1);
            if (s2)
                break;
        }
        str_free(s1);
        if (!s2)
        {
            scp = sub_context_new();
            sub_var_set_string(scp, "File_Name", wl[j]);
            change_error(cp, scp, i18n("$filename unrelated"));
            sub_context_delete(scp);
            ++number_of_errors;
            continue;
        }
        change_file_directory_query(cp, s2, &wl_in, 0);
        if (wl_in.size())
        {
            int             used;

            //
            // If the user named a directory, add all of the
            // source files in this change in that
            // directory, provided they were added using
            // the aecp command.
            //
            used = 0;
            for (k = 0; k < wl_in.size(); ++k)
            {
                string_ty       *s3;
                fstate_src_ty   *src_data;

                s3 = wl_in[k];
                src_data = cp->file_find(nstring(s3), view_path_first);
                assert(src_data);
                if (src_data)
                {
                    switch (src_data->action)
                    {
                    case file_action_modify:
                    case file_action_insulate:
                        if (wl2.member(s3))
                        {
                            scp = sub_context_new();
                            sub_var_set_string(scp, "File_Name", s3);
                            change_error(cp, scp, i18n("too many $filename"));
                            sub_context_delete(scp);
                            ++number_of_errors;
                        }
                        else
                            wl2.push_back(s3);
                        if (cp->file_is_config(s3))
                            ++config_seen;
                        ++used;
                        break;

                    case file_action_create:
                    case file_action_remove:
                    case file_action_transparent:
                        break;
                    }
                }
            }
            if (!used)
            {
                scp = sub_context_new();
                if (s2->str_length)
                    sub_var_set_string(scp, "File_Name", s2);
                else
                    sub_var_set_charstar(scp, "File_Name", ".");
                sub_var_set_long(scp, "Number", (long)wl_in.size());
                sub_var_optional(scp, "Number");
                change_error
                (
                    cp,
                    scp,
                    i18n("directory $filename contains no relevant files")
                );
                sub_context_delete(scp);
                ++number_of_errors;
            }
        }
        else
        {
            if (wl2.member(s2))
            {
                scp = sub_context_new();
                sub_var_set_string(scp, "File_Name", s2);
                change_error(cp, scp, i18n("too many $filename"));
                sub_context_delete(scp);
                ++number_of_errors;
            }
            else
                wl2.push_back(s2);
            if (cp->file_is_config(s2))
                ++config_seen;
        }
        str_free(s2);
    }
    wl = wl2;

    //
    // ensure that each file
    // 1. is already part of the change
    // 2. is being modified by this change
    //
    for (j = 0; j < wl.size(); ++j)
    {
        s1 = wl[j];
        fstate_src_ty *src_data = cp->file_find(nstring(s1), view_path_first);
        if (!src_data)
        {
            scp = sub_context_new();
            src_data = cp->file_find_fuzzy(nstring(s1), view_path_first);
            sub_var_set_string(scp, "File_Name", s1);
            if (src_data)
            {
                sub_var_set_string(scp, "Guess", src_data->file_name);
                change_error(cp, scp, i18n("no $filename, closest is $guess"));
            }
            else
                change_error(cp, scp, i18n("no $filename"));
            sub_context_delete(scp);
            ++number_of_errors;
            continue;
        }
        switch (src_data->action)
        {
        case file_action_modify:
        case file_action_insulate:
            break;

        case file_action_create:
        case file_action_remove:
        case file_action_transparent:
            scp = sub_context_new();
            sub_var_set_string(scp, "File_Name", s1);
            change_error(cp, scp, i18n("bad cp undo $filename"));
            sub_context_delete(scp);
            ++number_of_errors;
            continue;
        }
        if (config_seen && src_data->file_fp)
        {
            fingerprint_type.free(src_data->file_fp);
            src_data->file_fp = 0;
        }
    }
    if (!wl.size())
    {
        error_intl(0, i18n("no file names"));
        ++number_of_errors;
    }
    if (number_of_errors)
    {
        scp = sub_context_new();
        sub_var_set_long(scp, "Number", number_of_errors);
        sub_var_optional(scp, "Number");
        change_fatal(cp, scp, i18n("no files uncopied"));
        sub_context_delete(scp);
    }

    //
    // Remove each file from the development directory,
    // if it still exists.
    // Remove the difference file, too.
    //
    for (j = 0; j < wl.size(); ++j)
    {
        //
        // We cannot move the 'blf' and 'exists' declaration near the
        // first usage because some compiler (gcc-4.0.3) will complain
        // about jumps (gotos) that crosses initializazion of such
        // variables.
        //
        bool blf_unlink = false;
        bool exists = false;
        string_ty *blf = 0;

        s1 = wl[j];
        s2 = cp->file_path(s1);
        assert(s2);

        if (uninsulate)
        {
            fstate_src_ty *src_data =
                cp->file_find(nstring(s1), view_path_first);
            if (!src_data)
                goto not_this_one;
            switch (src_data->action)
            {
            case file_action_insulate:
                break;

            case file_action_create:
            case file_action_modify:
            case file_action_remove:
            case file_action_transparent:
                goto not_this_one;
            }
        }

        up->become_begin();
        exists = os_exists(s2);
        up->become_end();

        //
        // skip the changed files
        // if the user asked us to work on unchanged files
        //
        if (unchanged && exists)
        {
            int             different;
            fstate_src_ty   *src_data;
            fstate_src_ty   *psrc_data;

            //
            // Leave cross branch merges alone, even if they
            // don't change anything.  The information is
            // about the merge, not the file contents.
            //
            src_data = cp->file_find(nstring(s1), view_path_first);
            if (!src_data)
                goto not_this_one;
            if (src_data->edit_origin_new)
            {
                // Do not remove cross branch merges, the meta-data is imprtant.
                // FIXME: what about changed attributes with unchanged data?
                assert(src_data->edit_origin_new->revision);
                goto not_this_one;
            }
            switch (src_data->action)
            {
            case file_action_modify:
            case file_action_insulate:
                break;

            case file_action_create:
            case file_action_remove:
            case file_action_transparent:
                goto not_this_one;
            }

            //
            // The file could have vanished from under us,
            // so make sure this is sensable.
            //
            psrc_data = pp->file_find(src_data, view_path_extreme);
            if (!psrc_data)
                goto not_this_one;

            //
            // Compare the files.
            //
            blf = project_file_path(pp, psrc_data->file_name);
            assert(blf);
            {
                os_become_orig();
                bool blf_exists = os_exists(blf);
                os_become_undo();
                assert(blf_exists);
                if (!blf_exists)
                    blf = pp->file_version_path(psrc_data, blf_unlink);
            }

            up->become_begin();
            different = files_are_different(s2, blf);
            up->become_end();
            if (blf_unlink)
            {
                os_become_orig();
                os_unlink(blf);
                os_become_undo();
            }
            str_free(blf);
            if (different)
            {
                not_this_one:
                wl.remove(s1);
                --j;
                goto next;
            }
        }

        //
        // delete the file if it exists
        // and the users wants us to
        //
        if (exists && up->delete_file_query(nstring(s1), false, -1))
        {
            //
            // This is not as robust in the face of
            // errors as using commit.  Its merit
            // is its simplicity.
            //
            // It plays nice with the change_maintain_symlinks_to_basline
            // call, below.
            //
            // Also, the rename-and-delete shenanigans
            // take a long time over NFS, and users
            // expect this to be fast.
            //
            user_ty::become scoped(up);
            os_unlink_errok(s2);
        }

        //
        // always delete the difference file
        //
        up->become_begin();
        s1 = str_format("%s,D", s2->str_text);
        if (os_exists(s1))
            commit_unlink_errok(s1);
        str_free(s1);

        //
        // always delete the backup merge file
        //
        s1 = str_format("%s,B", s2->str_text);
        if (os_exists(s1))
            commit_unlink_errok(s1);
        str_free(s1);
        up->become_end();

        //
        // verbose success message
        // (possibly premature, but usually not)
        //
        {
            sub_context_ty sc;
            sc.var_set_string("File_Name", wl[j]);
            change_verbose(cp, &sc, i18n("copy file undo $filename complete"));
        }

        next:
        str_free(s2);
    }

    //
    // Remove each file from the change file,
    // and write it back out.
    //
    tests_uncopied = 0;
    for (j = 0; j < wl.size(); ++j)
    {
        fstate_src_ty   *psrc_data;

        cp->file_remove(wl[j]);

        //
        // See if there are any tests were uncopied by this action.
        //
        psrc_data = pp->file_find(wl[j], view_path_simple);
        if (!psrc_data)
            continue;
        switch (psrc_data->usage)
        {
        case file_usage_source:
        case file_usage_config:
        case file_usage_build:
            break;

        case file_usage_test:
        case file_usage_manual_test:
            tests_uncopied = 1;
            break;
        }
    }

    if (tests_uncopied)
    {
        int             more_tests;

        more_tests = 0;
        change_force_regression_test_exemption_undo(cp);
        for (j = 0; ; ++j)
        {
            fstate_src_ty   *src_data;

            src_data = change_file_nth(cp, j, view_path_first);
            if (!src_data)
                break;
            switch (src_data->usage)
            {
            case file_usage_test:
            case file_usage_manual_test:
                more_tests = 1;
                break;

            case file_usage_source:
            case file_usage_config:
            case file_usage_build:
                continue;
            }
            break;
        }
        if (!more_tests)
            change_rescind_test_exemption_undo(cp);
    }

    //
    // Only clear the various timestamps if we actually did something.
    //
    // This is especially important for aedist -receive, which
    // automagically calls aecpu -unch to make sure it supresses change
    // sets we already have.  But we don't want to clear the UUID if we
    // didn't remove any files from the change set.
    //
    if (wl.size() > 0)
    {
        //
        // the number of files changed,
        // so stomp on the validation fields.
        //
        change_build_times_clear(cp);

        //
        // If the file manifest of the change is altered (e.g. by aenf, aenfu,
        // aecp, aecpu, etc), or the contents of any file is changed, the
        // UUID is cleared.  This is because it is no longer the same change
        // as was received by aedist or aepatch, and the UUID is invalidated.
        //
        change_uuid_clear(cp);
    }

    //
    // Repair symlinks (etc) to the baseline.
    //
    // Warning: scarey build fu.
    //
    // On Tue, 2008-06-17 at 16:25 -0400, Cal Webster wrote:
    // > Since the recent upgrade to 4.24 "aecp -unc" has stopped recreating
    // > symbolic links for unchanged files in the development directory. They
    // > remain as real files.
    //
    // It is occasionally instructive to look at the code.
    //
    // The first thing to notice is where
    // change_create_symlinks_to_baseline is called from in the
    // code: (1) at the end of aedb, (2) on the new change after
    // aeclone, (3) after aeclean, **** (4) before aeb does anything.
    // The name is historical, it actually applies the development
    // directory style.  It's worth a read, if only to appreciate what
    // 512 development directory styles looks like.
    //
    // One of the things it can do is to replace a source file copy in
    // the dev dir with a newer version if the baseline has changed.
    // Actually, it unlinks, and does whatever the dev dir style wants,
    // e.g. a symlink.  This means that the transient files created by
    // aecpu will be sensibly replaced by a symlink should that file
    // change in the baseline.
    //
    // The next thing to look at is the
    // change_maintain_symlinks_to_baseline function, which is called by
    // all of the file undo commands (aecpu, aemvu, aemtu, aenfu, aentu)
    // after they do their thing.
    //
    // The difference between these two functions is that
    // [...]maintain[...] temporarily treats the {hard,sym}link styles
    // as copies for the purpose of undo... so there is something to
    // hang the new mod-time from, even though the contents are, well,
    // identical copies.
    //
    //
    // Now we can look at aecpu in particular.
    // The use case looks like this:
    //
    //  1. copy foo.c from baseline
    //  2. edit foo.c
    //  3. aeb, now have foo.o
    //  4. edit foo.c to be same as baseline
    //  5. aeb
    //  6. aecpu -unch (and have foo.c replaced by symlink into baseline)
    //  7. aeb does not need to rebuild foo.o, and does not
    //
    // It may be as simple as changing the last argument from
    //
    //     change_maintain_symlinks_to_baseline(cp, up, undoing);
    //
    // to
    //
    //     change_maintain_symlinks_to_baseline(cp, up, undoing && !unchanged);
    //
    // BUT there is still a problem in at least one use case:
    //
    //  1. copy foo.c from baseline
    //  2. edit foo.c
    //  3. build dev dir, now have foo.o
    //  4. edit foo.c to be same as baseline
    //     Note: no build here
    //  5. aecpu -unch
    //  6. aeb will *not* rebuild foo.o, even though it "obviously" should.
    //
    // The problem is that it isn't obvious to make.  It isn't obvious
    // to make because modtime(foo.o) > modtime (bl/foo.c) and is
    // therefore up-to-date.  Making the copy of the foo.c file in the
    // baseline into the development directory (even though it didn't
    // need to), and touching its mod time (this is The Important Bit),
    // takes care of this.
    //
    // So, no, in the general case we don't mess with the last argument.
    //
    bool undoing = true;
    change_maintain_symlinks_to_baseline(cp, up, undoing);

    // remember that we are about to
    bool recent_integration = cp->run_project_file_command_needed();
    if (recent_integration)
        cp->run_project_file_command_done();

    //
    // release the locks
    //
    cp->cstate_write();
    commit();
    lock_release();

    //
    // run the change file command
    // and the project file command if necessary
    //
    if (wl.size() > 0)
    {
        //
        // The only way to have no files is if we are doing "aecpu
        // -unch" and nothing has changed.  Every other code path which
        // would result in zero files is an error.  In the "aecpu -unch"
        // case, we don't want to perturb the change state when "aedist
        // -receive" uses this command.
        //
        cp->run_copy_file_undo_command(&wl, up);
    }
    if (recent_integration)
        cp->run_project_file_command(up);

    pp->free();
    trace(("}\n"));
}


void
copy_file_undo(void)
{
    static arglex_dispatch_ty dispatch[] =
    {
        { arglex_token_help, copy_file_undo_help, 0 },
        { arglex_token_list, copy_file_undo_list, 0 },
    };

    trace(("copy_file_undo()\n{\n"));
    arglex_dispatch(dispatch, SIZEOF(dispatch), copy_file_undo_main);
    trace(("}\n"));
}


// vim: set ts=8 sw=4 et :