#!/usr/bin/perl
use strict;
use warnings;
use DBI;
use File::Temp qw( tempfile );


# This program is under the GPL.
# Copyright (C) 2003 by Dylan William Hardison.

eval {
    require Time::Duration;
    1;
};


my ($cmd, $project, $sql, $db, $did_config) = (shift, shift);

while(1) {
    eval {
        $sql = require("$ENV{HOME}/.timesheetrc.pl");
    };
    if ($@) {
        write_config_file("$ENV{HOME}/.timesheetrc.pl");
        $did_config = 1;
    } else {
        last;
    }
}

eval {
    $db = DBI->connect("dbi:mysql:$sql->{db}",
        $sql->{user},
        $sql->{pass}, 
        { RaiseError => 1, PrintError => 0}
    );
};

if ($@) {
    warn "Error: " . DBI->errstr . "\n\n";
    if (DBI->err == 1044) {
        print <<"PRT";
    Why this happened:
You don't have permission to access the database...
This is because either the database doesn't exist,
or because you're not allowed to use it.

Create a database named $sql->{db},
with user $sql->{user} and password $sql->{pass}.
(You can configure those in by deleting $ENV{HOME}/.timesheetrc.pl
and re-running this program.)

PRT
    }
    exit(255);
}
        


check_db_table();
unless (defined $cmd) {
    die "Usage: ts <cmd> [project|project id] [args]\n" if not $did_config;
    exit(0);
}



if ($cmd eq 'start' or $cmd eq 'begin') {
    die "Undef project!" unless defined $project;
    
    my $proj = $db->quote($project);
    my $time = time();
    my $sql = qq{ INSERT INTO $sql->{table}
                  (project,start)
                  VALUES ($proj, FROM_UNIXTIME($time));
    };
    $db->do($sql);
    print "Started working on $project\n";
} elsif ($cmd eq 'stop' or $cmd eq 'end') {
    die "Undef project!" unless defined $project;
    
    my ($select, $update, $result, $id, $start, $pname);
    if ($project =~ /\D/) {
        $select = qq{ SELECT id,UNIX_TIMESTAMP(start),project FROM $sql->{table}
                      WHERE (project = ? AND stop IS NULL);
        };
    } else {
        $select = qq{ SELECT id,UNIX_TIMESTAMP(start),project FROM $sql->{table}
                      WHERE (id = ? AND stop IS NULL);
        };
    }

    $update = qq{ UPDATE $sql->{table}
                  SET stop = FROM_UNIXTIME(?)
                  WHERE (id = ?)
    };
    $result = $db->prepare($select);
    $result->execute($project);
    
    ($id, $start, $pname) = $result->fetchrow_array;
    if (defined $id) {
        my $stop = time();
        my $diff = $stop - $start;
    
        print "Worked on $pname for ", duration($diff, 5) ,"\n";
        $result = $db->prepare($update);
        $result->execute($stop, $id);
    } else {
        if ($project =~ /\D/) {
            print "But, we haven't ever started $pname!\n";
        } else {
            print "We already stopped working on $pname!\n";
        }
    }
} elsif ($cmd eq 'total') {
    if (defined $project) {
        show_total($project);
    } else {
        show_total_all();
    }
} elsif ($cmd eq 'active' or $cmd eq 'act') {
    my $select = qq{
        SELECT project,id FROM $sql->{table}
        WHERE stop IS NULL;
    };
    my $result = $db->prepare($select);
    $result->execute();
    my ($p, $id);
    while (($p,$id) = $result->fetchrow_array) {
        print "Active: $p ($id)\n";
    }
} elsif ($cmd eq 'list' or $cmd eq 'ls') {
    my $select = qq{
        SELECT DISTINCT project FROM $sql->{table};
    };
    my $result = $db->prepare($select);
    $result->execute();
    my $list = $result->fetchall_arrayref;
    my $count = @$list;

    unless ($count == 0) {
        print "Found $count projects:\n";
        foreach my $item (@$list) {
            print "\t- $item->[0]\n";
        }
    } else {
        print "No projects found.\n";
    }
} elsif ($cmd eq 'index') {
    my $select = qq{
        SELECT id,project FROM $sql->{table};
    };
    my $result = $db->prepare($select);
    $result->execute();
    my $list = $result->fetchall_arrayref;
    my $count = @$list;

    unless ($count == 0) {
        print "Index of Projects:\n";
        foreach my $item (@$list) {
            print "\t- $item->[1] ($item->[0])\n";
        }
    } else {
        print "No projects found.\n";
    }
} elsif ($cmd eq 'average' or $cmd eq 'avg') {
    my $select = qq(
        SELECT project,AVG(UNIX_TIMESTAMP(stop) - UNIX_TIMESTAMP(start)) AS average
        FROM $sql->{table}
        #WHERE#
        GROUP BY project
        ORDER BY id ASC
    );
    if (defined $project) {
        my $p = $db->quote($project);
        $select =~ s/#WHERE#\n/WHERE (project = $p)\n/;
    } else {
        $select =~ s/#WHERE#\n//;
    }

    my $result = $db->prepare($select);
    $result->execute();
    my $item;

    my $did_loop = 0;
    while ($item = $result->fetchrow_hashref) {
        $did_loop++;
        print "$item->{project}: Average time was ", duration($item->{average}, 5), "\n";
    }

    unless ($did_loop) {
        print "No average time...\n";
    }
} elsif ($cmd eq 'purge') {
    my $e = prompt("Are you sure you want to purge timesheet?\n(yes/no, default no)");
    if ($e =~ /^y(es?)$/) {
        print "Deleted everything from database.\n";
        $db->do("DELETE FROM $sql->{table};");
    }
} elsif ($cmd eq 'delete' or $cmd eq 'del') {
    die "Undef project!" unless defined $project;
    my $delete;
    my $name;

    if ($project =~ /\D/) {
        # $project is project name.
        $delete = qq(
            DELETE FROM $sql->{table} WHERE project = ?
        );
        $name = $project;
    } else {
        # $project is project id.
        $name = id_to_project($project); # get name of project id.
        $delete = qq{
            DELETE FROM $sql->{table} WHERE id = ?
        };
    }
    my $result = $db->prepare($delete);
    $result->execute($project);
    print "Deleted $name from database.\n";
} else {    print "Unknown command: $cmd\n";
}
    

END {
    if ($db) {
        $db->disconnect;
    }
}

sub show_total {
    my ($project) = @_;
    my $select = qq{
        SELECT sum(UNIX_TIMESTAMP(stop) - UNIX_TIMESTAMP(start)) AS diff_sum
        FROM $sql->{table}
        WHERE (project = ? AND start IS NOT NULL AND stop IS NOT NULL)
        GROUP BY project;
    };
    my ($total, $entry, $result);
    $total = 0;
    $result = $db->prepare($select);
    $result->execute($project);
    ($total) = $result->fetchrow_array() || 0;

    if ($total > 0) {
        print $project, ": Worked on for ", duration($total, 5),"\n";
    } else {
        print "Haven't ever worked on $project...\n";
    }
}

sub show_total_all {
    my ($project) = @_;
    my $select = qq{
        SELECT project,sum(UNIX_TIMESTAMP(stop) - UNIX_TIMESTAMP(start)) AS diff_sum
        FROM $sql->{table}
        WHERE (start IS NOT NULL AND stop IS NOT NULL)
        GROUP BY project
        ORDER BY diff_sum DESC
    };
    my ($total, $result, $name);
    $total = 0;
    $result = $db->prepare($select);
    $result->execute();
    
    while (($name, $total) = $result->fetchrow_array) {
        if ($total > 0) {
            print $name, ": Worked on for ", duration($total, 5),"\n";
        } else {
            print "Haven't ever worked on $name...\n";
        }
    }
}


sub id_to_project {
    my ($id) = @_;
    my $select = qq{
        SELECT project
        FROM $sql->{table}
        WHERE id = $id;
    };
    my $result = $db->prepare($select);
    $result->execute();
    my ($name) = $result->fetchrow_array;

    return $name;
}

sub write_config_file {
    my ($file) = @_;
    my $cfg = <<CONFIG;
#!/usr/bin/perl

{
    table => "timesheet", # Table name. DO NOT CHANGE!
    db => "DBNAME",       # Database name. Change.
    user => "USER",       # Username. Change.
    pass => "PASSWORD",   # Password. Change.
};
CONFIG

    if (not -f $file) {
        while (1) {
            my $in = prompt(
                "Config file doesn't exist. Do you want to create it now?\n"
                ."(yes/no)"
            );
            if ($in =~ /^y(es)?$/) {
                my ($dbname, $user, $password);
                print "\nOkay, I'm going to ask you some questions about ",
                "your mysql database account,\n",
                "I need this information to function.\n";
                $user     = prompt("User name");
                $password = prompt("Password");
                $dbname   = prompt("Name of database", $user);
                $cfg =~ s/DBNAME/$dbname/g;
                $cfg =~ s/USER/$user/g;
                $cfg =~ s/PASSWORD/$password/g;
                write_str_to_file($cfg, $file);
                my $edit = prompt("Edit config file? (yes/no, default: no)");
                if ($edit =~ /^y(es)?$/) {
                    edit_file($file);
                }
                print "Thanks!\n";
                last;
            } elsif ($in =~ /^no?$/) {
                last;
            } else {
                print "I don't understand that.\n";
                next;
            }
        }
    }
}

sub write_str_to_file {
    my ($s, $file) = @_;
    open my $fh, ">$file" or die "Can't open $file for writting: $!";
    print $fh $s;
    close $fh;
    chmod 0600, $file;
}

sub prompt {
    my ($prompt, $default) = @_;
    my $value;

    if (have("Term::ReadLine")) {
        
    } else {
        if (defined $default) {
            print "$prompt (default: $default): ";
        } else {
            print $prompt, ": ";
        }
        $value = readline STDIN;
        chomp $value;
        return $value || $default || '';
    }
}

sub duration {
    if (have("Time::Duration")) {
        goto &Time::Duration::duration;
    } else {
        $_[0] += 0;
        return "$_[0] seconds";
    }
}

sub have {
    my ($file) = @_;
    $file =~ s!::!/!;
    $file .= ".pm";

    return exists $INC{$file};
}

sub check_db_table {
    eval {
        $db->do("SELECT id FROM $sql->{table} LIMIT 1");
    };
    if ($@) {
        if ($db->errstr =~ /Table '$sql->{db}\.$sql->{table}' doesn't exist/i) {
            configure_db_table();
        }
    }
}

sub configure_db_table {
    print "Configuring database table automagically.\n";
    local $/ = undef;
    my $s = readline DATA;
    $s =~ s/#TABLE#/$sql->{table}/g;
    $db->do($s);

}

sub edit_file {
    my ($file) = @_;
    system($ENV{VISUAL} || $ENV{EDITOR} || "vi", $file);
}

__DATA__

CREATE TABLE #TABLE# (
    id INTEGER NOT NULL AUTO_INCREMENT,
    project VARCHAR(80),
    start DATETIME,
    stop DATETIME,
    PRIMARY KEY (id)
);