using Microsoft.Data.Sqlite;

namespace MoShiro.Backend.Storage.Sqlite;

/// <summary>表结构。版本记录在 <c>PRAGMA user_version</c>；以后的迁移是按版本号追加的内置 SQL。</summary>
internal static class Schema
{
    public const int CurrentVersion = 7;

    public static void Migrate(SqliteConnection connection)
    {
        int version = connection.Scalar<int>("PRAGMA user_version");
        if (version > CurrentVersion)
        {
            throw new InvalidOperationException($"database schema version {version} is newer than this build supports ({CurrentVersion})");
        }

        if (version < 1)
        {
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec(V1);
            connection.Exec("PRAGMA user_version = 1");
            transaction.Commit();
        }

        if (version < 2)
        {
            // 测试属于一条线路（Probe，Agent）：旧测试没有 Probe，留空
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("ALTER TABLE tests ADD COLUMN probe_id TEXT NOT NULL DEFAULT ''");
            connection.Exec("CREATE INDEX ix_tests_line ON tests (agent_id, probe_id, requested_at)");
            connection.Exec("PRAGMA user_version = 2");
            transaction.Commit();
        }

        if (version < 3)
        {
            // 主机资源占用的历史（每个 Agent 每分钟一行）
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("""
                CREATE TABLE host_samples (
                  agent_id TEXT NOT NULL,
                  at INTEGER NOT NULL,
                  cpu REAL,
                  mem_used INTEGER,
                  mem_total INTEGER,
                  disk_used INTEGER,
                  disk_total INTEGER,
                  net_rx_bps INTEGER,
                  net_tx_bps INTEGER,
                  uptime INTEGER,
                  PRIMARY KEY (agent_id, at)
                ) WITHOUT ROWID;
                """);
            connection.Exec("PRAGMA user_version = 3");
            transaction.Commit();
        }

        if (version < 4)
        {
            // 节点的展示信息：系统、架构、国家、运营商；geo_host 是查询用的地址，只在 Backend 内部用
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("""
                CREATE TABLE node_meta (
                  node_id TEXT PRIMARY KEY,
                  kind TEXT NOT NULL,
                  os TEXT,
                  os_name TEXT,
                  arch TEXT,
                  country TEXT,
                  isp_key TEXT,
                  isp_name TEXT,
                  geo_host TEXT,
                  geo_at INTEGER NOT NULL DEFAULT 0,
                  updated_at INTEGER NOT NULL DEFAULT 0
                ) WITHOUT ROWID
                """);
            connection.Exec("PRAGMA user_version = 4");
            transaction.Commit();
        }

        if (version < 5)
        {
            // 节点自报的构建信息：版本、tag、提交、构建时间
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("ALTER TABLE node_meta ADD COLUMN version TEXT");
            connection.Exec("ALTER TABLE node_meta ADD COLUMN tag TEXT");
            connection.Exec("ALTER TABLE node_meta ADD COLUMN commit_id TEXT");
            connection.Exec("ALTER TABLE node_meta ADD COLUMN built_at TEXT");
            connection.Exec("PRAGMA user_version = 5");
            transaction.Commit();
        }

        if (version < 6)
        {
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("ALTER TABLE agents ADD COLUMN ipv6_host TEXT NOT NULL DEFAULT ''");
            connection.Exec("ALTER TABLE agents ADD COLUMN ipv6_supported INTEGER NOT NULL DEFAULT 0");
            connection.Exec("ALTER TABLE tests ADD COLUMN ip_version TEXT NOT NULL DEFAULT 'ipv4'");
            connection.Exec("CREATE INDEX ix_tests_path ON tests (agent_id, probe_id, ip_version, requested_at)");
            connection.Exec("PRAGMA user_version = 6");
            transaction.Commit();
        }

        if (version < 7)
        {
            using SqliteTransaction transaction = connection.BeginTransaction();
            connection.Exec("ALTER TABLE agents ADD COLUMN ipv6_diagnostics TEXT");
            connection.Exec("ALTER TABLE probes ADD COLUMN ipv6_diagnostics TEXT");
            connection.Exec("PRAGMA user_version = 7");
            transaction.Commit();
        }
    }

    /// <summary>
    /// 新增 Kind 或指标都不需要改表结构：指标是 <c>metric_*.metrics</c> 里的一个键，Kind 只是 <c>raw_chunks.kind</c> 的一个取值。
    /// </summary>
    private const string V1 = """
        CREATE TABLE agents (
          id TEXT PRIMARY KEY,
          name TEXT NOT NULL,
          status TEXT NOT NULL,
          pubkey BLOB NOT NULL,
          tls_spki BLOB NOT NULL,
          public_host TEXT NOT NULL DEFAULT '',
          probe_tcp_port INTEGER NOT NULL DEFAULT 7443,
          probe_udp_ports TEXT NOT NULL DEFAULT '[7443]',
          labels TEXT NOT NULL DEFAULT '[]',
          public_visible INTEGER NOT NULL DEFAULT 1,
          kinds TEXT NOT NULL DEFAULT '[]',
          agent_version TEXT,
          local_limits TEXT,
          task_version INTEGER NOT NULL DEFAULT 0,
          applied_task_version INTEGER NOT NULL DEFAULT 0,
          rejected TEXT,
          task_hash TEXT,
          meta TEXT,
          created_at INTEGER NOT NULL,
          last_seen_at INTEGER,
          row_version INTEGER NOT NULL DEFAULT 0
        );
        -- 同名节点只允许一个已建立的（pending 的可以重名，等待管理员接管或改名）
        CREATE UNIQUE INDEX ux_agents_name ON agents (name) WHERE status <> 'pending';

        CREATE TABLE join_tokens (
          id TEXT PRIMARY KEY,
          token_sha256 BLOB NOT NULL UNIQUE,
          note TEXT,
          labels TEXT NOT NULL DEFAULT '[]',
          auto_approve INTEGER NOT NULL,
          max_uses INTEGER NOT NULL,
          uses INTEGER NOT NULL DEFAULT 0,
          expires_at INTEGER NOT NULL,
          revoked_at INTEGER,
          created_at INTEGER NOT NULL
        );

        CREATE TABLE probes (
          id TEXT PRIMARY KEY,
          name TEXT NOT NULL,
          pubkey BLOB NOT NULL,
          created_at INTEGER NOT NULL,
          revoked_at INTEGER
        );

        CREATE TABLE users (
          id TEXT PRIMARY KEY,
          username TEXT NOT NULL UNIQUE,
          password_hash BLOB NOT NULL,
          password_salt BLOB NOT NULL,
          iterations INTEGER NOT NULL,
          created_at INTEGER NOT NULL
        );
        CREATE TABLE sessions (
          id_sha256 BLOB PRIMARY KEY,
          user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
          csrf_token BLOB NOT NULL,
          created_at INTEGER NOT NULL,
          expires_at INTEGER NOT NULL
        );
        CREATE TABLE api_tokens (
          id TEXT PRIMARY KEY,
          name TEXT NOT NULL,
          scope TEXT NOT NULL,
          token_sha256 BLOB NOT NULL UNIQUE,
          created_at INTEGER NOT NULL,
          last_used_at INTEGER,
          revoked_at INTEGER
        );
        CREATE TABLE settings (key TEXT PRIMARY KEY, value TEXT NOT NULL);

        CREATE TABLE tasks (
          id TEXT PRIMARY KEY,
          scope TEXT NOT NULL,
          agent_id TEXT REFERENCES agents(id) ON DELETE CASCADE,
          base_task_id TEXT REFERENCES tasks(id) ON DELETE CASCADE,
          kind TEXT NOT NULL,
          target TEXT,
          params TEXT NOT NULL DEFAULT '{}',
          schedule TEXT NOT NULL,
          enabled INTEGER NOT NULL DEFAULT 1,
          updated_at INTEGER NOT NULL,
          row_version INTEGER NOT NULL DEFAULT 0
        );

        CREATE TABLE tests (
          id TEXT PRIMARY KEY,
          agent_id TEXT NOT NULL,
          plan TEXT NOT NULL,
          params TEXT NOT NULL,
          trigger TEXT NOT NULL,
          status TEXT NOT NULL,
          error_code TEXT,
          phase INTEGER,
          phase_count INTEGER NOT NULL DEFAULT 0,
          requested_at INTEGER NOT NULL,
          started_at INTEGER,
          finished_at INTEGER
        );
        CREATE INDEX ix_tests_agent ON tests (agent_id, requested_at);
        CREATE TABLE test_results (
          test_id TEXT PRIMARY KEY,
          metrics BLOB NOT NULL,
          series BLOB NOT NULL
        ) WITHOUT ROWID;

        CREATE TABLE raw_segments (
          id INTEGER PRIMARY KEY,
          day TEXT NOT NULL,
          path TEXT NOT NULL UNIQUE,
          bytes INTEGER NOT NULL DEFAULT 0
        );
        CREATE TABLE raw_chunks (
          chunk_id TEXT PRIMARY KEY,
          segment_id INTEGER NOT NULL REFERENCES raw_segments(id),
          offset INTEGER NOT NULL,
          length INTEGER NOT NULL,
          agent_id TEXT NOT NULL,
          series TEXT NOT NULL,
          kind TEXT NOT NULL,
          task_id TEXT,
          test_id TEXT,
          phase INTEGER,
          start_ts INTEGER NOT NULL,
          duration_ms INTEGER NOT NULL,
          partial INTEGER NOT NULL
        ) WITHOUT ROWID;
        CREATE INDEX ix_raw_series ON raw_chunks (agent_id, series, start_ts);
        CREATE INDEX ix_raw_test ON raw_chunks (test_id) WHERE test_id IS NOT NULL;
        CREATE INDEX ix_raw_segment ON raw_chunks (segment_id);

        CREATE TABLE metric_10s (agent_id TEXT NOT NULL, series TEXT NOT NULL, window_start INTEGER NOT NULL, partial INTEGER NOT NULL, metrics BLOB NOT NULL, PRIMARY KEY (agent_id, series, window_start)) WITHOUT ROWID;
        CREATE TABLE metric_1m  (agent_id TEXT NOT NULL, series TEXT NOT NULL, window_start INTEGER NOT NULL, partial INTEGER NOT NULL, metrics BLOB NOT NULL, PRIMARY KEY (agent_id, series, window_start)) WITHOUT ROWID;
        CREATE TABLE metric_5m  (agent_id TEXT NOT NULL, series TEXT NOT NULL, window_start INTEGER NOT NULL, partial INTEGER NOT NULL, metrics BLOB NOT NULL, PRIMARY KEY (agent_id, series, window_start)) WITHOUT ROWID;
        CREATE TABLE metric_1h  (agent_id TEXT NOT NULL, series TEXT NOT NULL, window_start INTEGER NOT NULL, partial INTEGER NOT NULL, metrics BLOB NOT NULL, PRIMARY KEY (agent_id, series, window_start)) WITHOUT ROWID;
        CREATE INDEX ix_metric_10s_time ON metric_10s (window_start);
        CREATE INDEX ix_metric_1m_time ON metric_1m (window_start);
        CREATE INDEX ix_metric_5m_time ON metric_5m (window_start);

        CREATE TABLE metric_versions (
          metric_id TEXT PRIMARY KEY,
          fingerprint TEXT NOT NULL,
          recompute_from INTEGER,
          recompute_cursor INTEGER
        );

        CREATE TABLE analysis_queue (
          agent_id TEXT NOT NULL,
          series TEXT NOT NULL,
          window_start INTEGER NOT NULL,
          not_before INTEGER NOT NULL,
          reason TEXT NOT NULL,
          seq INTEGER NOT NULL DEFAULT 1,
          PRIMARY KEY (agent_id, series, window_start)
        ) WITHOUT ROWID;
        CREATE INDEX ix_queue_due ON analysis_queue (not_before);
        CREATE TABLE rollup_dirty (
          level INTEGER NOT NULL,
          agent_id TEXT NOT NULL,
          series TEXT NOT NULL,
          bucket_start INTEGER NOT NULL,
          PRIMARY KEY (level, agent_id, series, bucket_start)
        ) WITHOUT ROWID;

        CREATE TABLE events (
          id INTEGER PRIMARY KEY,
          agent_id TEXT,
          kind TEXT NOT NULL,
          at INTEGER NOT NULL,
          detail TEXT
        );
        CREATE INDEX ix_events_time ON events (at);
        CREATE INDEX ix_events_agent ON events (agent_id, at);
        """;
}