-- gitea-saas-core billing schema (SQLite).
--
-- Idempotent by construction: every object is created with IF NOT EXISTS,
-- so executing this file any number of times is safe.
--
-- Conventions:
--   * All amounts are INTEGER minor units (cents). No floats, ever.
--   * Currency defaults to USD.
--   * Timestamps are ISO-8601 UTC text written by the application layer;
--     the DEFAULT expressions are fallbacks for manual/one-off inserts only.
--   * ledger.kind is constrained to {credit, debit, hold, release, refund}.
--   * ledger.idempotency_key is globally UNIQUE: every mutation is replay-safe.

CREATE TABLE IF NOT EXISTS clients (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    name       TEXT    NOT NULL UNIQUE,
    tier       TEXT    NOT NULL DEFAULT 'free',
    status     TEXT    NOT NULL DEFAULT 'active',
    meta_json  TEXT    NOT NULL DEFAULT '{}',
    created_at TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
);

CREATE TABLE IF NOT EXISTS ledger (
    id              INTEGER PRIMARY KEY AUTOINCREMENT,
    client_id       INTEGER NOT NULL REFERENCES clients(id),
    kind            TEXT    NOT NULL CHECK (kind IN ('credit', 'debit', 'hold', 'release', 'refund')),
    amount_minor    INTEGER NOT NULL CHECK (amount_minor >= 0),
    currency        TEXT    NOT NULL DEFAULT 'USD',
    idempotency_key TEXT    NOT NULL UNIQUE,
    ref_type        TEXT,
    ref_id          TEXT,
    created_at      TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
);

CREATE TABLE IF NOT EXISTS holds (
    id           INTEGER PRIMARY KEY AUTOINCREMENT,
    client_id    INTEGER NOT NULL REFERENCES clients(id),
    amount_minor INTEGER NOT NULL CHECK (amount_minor >= 0),
    ref_type     TEXT,
    ref_id       TEXT,
    expires_at   TEXT    NOT NULL,
    released_at  TEXT
);

-- Balance / listing lookups.
CREATE INDEX IF NOT EXISTS idx_ledger_client_created ON ledger (client_id, created_at, id);
CREATE INDEX IF NOT EXISTS idx_ledger_client_kind    ON ledger (client_id, kind);
CREATE INDEX IF NOT EXISTS idx_holds_client          ON holds (client_id);
CREATE INDEX IF NOT EXISTS idx_holds_stale           ON holds (client_id) WHERE released_at IS NULL;