package Sietima::MailStore::FS;
use Moo;
use Sietima::Policy;
use Types::Path::Tiny qw(Dir);
use Types::Standard qw(Object ArrayRef Str slurpy);
use Type::Params qw(compile);
use Sietima::Types qw(EmailMIME);
use Digest::SHA1 qw(sha1_hex);
use namespace::clean;

with 'Sietima::MailStore';

has root => (
    is => 'ro',
    required => 1,
    isa => Dir,
    coerce => 1,
);

has [qw(_tagdir _msgdir)] => ( is => 'lazy' );
sub _build__tagdir($self) { $self->root->child('tags') }
sub _build__msgdir($self) { $self->root->child('msgs') }

sub BUILD($self,@) {
    $self->$_->mkpath for qw(_tagdir _msgdir);
    return;
}

sub clear($self) {
    do { $self->$_->remove_tree;$self->$_->mkpath } for qw(_tagdir _msgdir);
    return;
}

sub store($self,$mail,@tags) {
    state $check = compile(Object,EmailMIME,slurpy ArrayRef[Str]);$check->(@_);

    my $str = $mail->as_string;
    my $id = sha1_hex($str);

    $self->_msgdir->child($id)->spew_raw($str);

    $self->_tagdir->child($_)->append("$id\n") for @tags;

    return $id;
}

sub retrieve_by_id($self,$id) {
    state $check = compile(Object,Str);$check->(@_);

    my $msg_path = $self->_msgdir->child($id);
    return unless -e $msg_path;
    return Email::MIME->new($msg_path->slurp_raw);
}

sub _tagged_by($self,$tag) {
    my $tag_file = $self->_tagdir->child($tag);
    return unless -e $tag_file;
    return $tag_file->lines({chomp=>1});
}

sub retrieve_ids_by_tags($self,@tags) {
    state $check = compile(Object,slurpy ArrayRef[Str]);$check->(@_);

    my %msgs;
    if (@tags) {
        for my $tag (@tags) {
            $_++ for @msgs{$self->_tagged_by($tag)};
        }
    }
    else {
        $msgs{$_->basename}=0 for $self->_msgdir->children;
    }

    my @ret;
    for my $id (keys %msgs) {
        next unless $msgs{$id} == @tags;
        push @ret, $id;
    }
    return \@ret;
}

sub retrieve_by_tags($self,@tags) {
    state $check = compile(Object,slurpy ArrayRef[Str]);$check->(@_);

    my @ret;
    for my $id ($self->retrieve_ids_by_tags(@tags)->@*) {
        push @ret, {
            id => $id,
            mail => $self->retrieve_by_id($id),
        };
    }

    return \@ret;
}

sub remove($self,$id) {
    state $check = compile(Object,Str);$check->(@_);

    for my $tag_file ($self->_tagdir->children) {
        $tag_file->edit_lines( sub { $_='' if /\A\Q$id\E\n?\z/ } );
    }
    $self->_msgdir->child($id)->remove;

    return;
}

1;