#include "store/migrations.hpp"

#include <algorithm>

// Generated at build time from store/migrations/*.sql by embed_migrations.cmake.
#include "migrations_embedded.hpp"

namespace velox::daemon::store {

std::span<const Migration> embedded_migrations() {
    return {kEmbeddedMigrations.data(), kEmbeddedMigrations.size()};
}

DbResult<MigrationOutcome> migrate_to_head(Db& db) {
    const auto all = embedded_migrations();

    MigrationOutcome out;
    out.from_version = db.user_version();
    out.to_version = out.from_version;
    if (out.from_version < 0) {
        return std::unexpected(DbError{0, "could not read PRAGMA user_version"});
    }

    for (const auto& m : all) {
        if (m.version <= out.from_version) continue;

        // Each migration is one transaction: a failure half-way leaves user_version and
        // the schema exactly where they were.
        auto r = db.transaction([&]() -> DbResult<void> {
            if (auto e = db.exec(m.sql); !e) return e;
            return db.set_user_version(m.version);
        });
        if (!r) {
            return std::unexpected(DbError{r.error().code, "migration " + std::string(m.name) +
                                                              " failed: " + r.error().message});
        }
        out.to_version = m.version;
        ++out.applied;
    }

    return out;
}

}  // namespace velox::daemon::store