Adding db and migrations.

lib/MakeThemPay/DB.pm

@@ -0,0 +1,112 @@
+package MakeThemPay::DB;
+
+use v5.40.0;
+
+use strict;
+use warnings;
+use utf8;
+
+use DBI;
+use Path::Tiny;
+
+use MakeThemPay::DB::Migrations;
+
+my $dbh;
+
+sub connect {
+    if ( defined $dbh ) {
+        return $dbh;
+    }
+    my $class    = shift;
+    my $database = $class->database;
+    $dbh = DBI->connect(
+        "dbi:SQLite:dbname=$database",
+        ,
+        undef, undef,
+        {
+            RaiseError => 1,
+        },
+    );
+    $class->_migrate($dbh);
+    return $dbh;
+}
+
+sub database($class) {
+    my $home = $ENV{HOME};
+    my $flatpak_config_dir = $ENV{XDG_CONFIG_HOME};
+    my $db_path = '';
+    {
+	if ($flatpak_config_dir) {
+            $db_path = $flatpak_config_dir . '/';	
+            next;
+	}
+	$db_path = $home . '/' if $home; 
+    }
+    $db_path .= '.make-them-pay/db.sqlite';
+    path($db_path)->parent->mkpath;
+    return $db_path;
+
+}
+
+sub _migrate {
+    my $class = shift;
+    my $dbh   = shift;
+    local $dbh->{RaiseError} = 0;
+    local $dbh->{PrintError} = 0;
+    my @migrations = MakeThemPay::DB::Migrations::MIGRATIONS();
+    if ( $class->get_current_migration($dbh) > @migrations ) {
+        warn "Something happened there, wrong migration number.";
+    }
+    if ( $class->get_current_migration($dbh) >= @migrations ) {
+        say STDERR "Migrations already applied.";
+        return;
+    }
+    $class->_apply_migrations( $dbh, \@migrations );
+}
+
+sub _apply_migrations {
+    my $class      = shift;
+    my $dbh        = shift;
+    my $migrations = shift;
+    for (
+        my $i = $class->get_current_migration($dbh) ;
+        $i < @$migrations ;
+        $i++
+      )
+    {
+        local $dbh->{RaiseError} = 1;
+        my $current_migration = $migrations->[$i];
+        my $migration_number  = $i + 1;
+        $class->_apply_migration( $dbh, $current_migration, $migration_number );
+    }
+}
+
+sub _apply_migration {
+    my $class             = shift;
+    my $dbh               = shift;
+    my $current_migration = shift;
+    my $migration_number  = shift;
+    {
+        if (ref $current_migration eq 'CODE') {
+            $current_migration->($dbh);
+            next;
+        }
+        $dbh->do($current_migration);
+    }
+    $dbh->do( <<'EOF', undef, 'current_migration', $migration_number );
+INSERT INTO options
+VALUES ($1, $2) 
+ON CONFLICT (name) DO 
+UPDATE SET value = $2;
+EOF
+}
+
+sub get_current_migration {
+    my $class  = shift;
+    my $dbh    = shift;
+    my $result = $dbh->selectrow_hashref( <<'EOF', undef, 'current_migration' );
+select value from options where name = ?;
+EOF
+    return int( $result->{value} // 0 );
+}
+1;

lib/MakeThemPay/DB/Migrations.pm

@@ -0,0 +1,23 @@
+package MakeThemPay::DB::Migrations;
+
+use v5.40.0;
+
+use strict;
+use warnings;
+use utf8;
+
+use feature 'signatures';
+
+sub MIGRATIONS {
+    return (
+        'CREATE TABLE options (
+            name TEXT PRIMARY KEY,
+            value TEXT
+        );',
+        'CREATE TABLE licenses (
+            uuid TEXT PRIMARY KEY,
+            paid INTEGER DEFAULT 0
+        );',
+    );
+}
+1;