feat: add Config with account, query, and sync parsing

Accounts use [account.work] rather than [account/work]: QSettings' INI
backend treats "/" as its own hierarchical group separator, so a literal
slash in a section header parses as a nested group and trips
QSettings::FormatError, silently breaking childGroups() enumeration. A
dot carries no such meaning and keeps the format flat.

Saved-query order is alphabetical (QSettings::childKeys() sorts), not
file order; documented in code and tests rather than left to a false
assumption.

1 files changed, 62 insertions, 0 deletions

diff --git a/src/config.h b/src/config.h
new file mode 100644
index 0000000..f037db5
--- /dev/null
+++ b/src/config.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include <QList>
+#include <QString>
+#include <QStringList>
+
+/// One mail account. notmuch has no concept of accounts; it sees a single flat
+/// tree. An account is therefore a path prefix within that tree plus an
+/// identity.
+struct Account
+{
+    QString key;      ///< INI group suffix, e.g. "work" from [account/work].
+    QString name;
+    QString address;
+    QString maildir;  ///< Relative to notmuch's database.path.
+    QString drafts;   ///< Unused in v1; send is v2.
+
+    bool isValid() const { return !key.isEmpty() && !maildir.isEmpty(); }
+
+    /// Restricts a notmuch query to this account's subtree.
+    QString scopedQuery(const QString &query) const;
+};
+
+struct SavedQuery
+{
+    QString name;
+    QString query;
+};
+
+/// Reads ~/.config/qtmaildir/qtmaildir.conf.
+///
+/// The Maildir path is deliberately NOT configurable here: notmuch already
+/// stores it as database.path and libnotmuch reads it. Duplicating it would
+/// allow the GUI to index a different tree than the CLI.
+class Config
+{
+public:
+    /// Path used when load() is called with no argument.
+    static QString defaultPath();
+
+    void load(const QString &path);
+
+    QList<Account> accounts() const { return m_accounts; }
+    Account account(const QString &key) const;
+    QList<SavedQuery> savedQueries() const { return m_savedQueries; }
+
+    /// Empty when unset; the caller disables the Sync button in that case.
+    QString syncCommand() const { return m_syncCommand; }
+
+    /// Optional alternate notmuch config file. Empty means "let notmuch decide".
+    QString notmuchConfig() const { return m_notmuchConfig; }
+
+    /// Non-fatal problems, shown once in a startup banner.
+    QStringList warnings() const { return m_warnings; }
+
+private:
+    QList<Account> m_accounts;
+    QList<SavedQuery> m_savedQueries;
+    QString m_syncCommand;
+    QString m_notmuchConfig;
+    QStringList m_warnings;
+};