-- +goose Up
ALTER TABLE devices
    ADD COLUMN accessibility_enabled INTEGER NOT NULL DEFAULT 0
        CHECK (accessibility_enabled IN (0, 1));

ALTER TABLE devices
    ADD COLUMN pdd_installed INTEGER NOT NULL DEFAULT 0
        CHECK (pdd_installed IN (0, 1));

ALTER TABLE devices
    ADD COLUMN readiness_reported_at TEXT;

ALTER TABLE purchase_tasks
    ADD COLUMN claimed_by_user_id TEXT
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT;

ALTER TABLE purchase_tasks
    ADD COLUMN claimed_by_device_id TEXT
        REFERENCES devices(id) ON UPDATE RESTRICT ON DELETE RESTRICT;

ALTER TABLE purchase_tasks
    ADD COLUMN claim_generation INTEGER NOT NULL DEFAULT 0
        CHECK (claim_generation >= 0);

ALTER TABLE purchase_tasks
    ADD COLUMN claim_token_hash TEXT
        CHECK (
            claim_token_hash IS NULL
            OR (
                length(claim_token_hash) = 64
                AND claim_token_hash NOT GLOB '*[^0-9a-f]*'
            )
        );

ALTER TABLE purchase_tasks
    ADD COLUMN claim_issued_at TEXT;

ALTER TABLE purchase_tasks
    ADD COLUMN claim_expires_at TEXT;

ALTER TABLE purchase_tasks
    ADD COLUMN cancel_requested_at TEXT;

ALTER TABLE purchase_tasks
    ADD COLUMN cancel_requested_by_user_id TEXT
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT;

CREATE UNIQUE INDEX purchase_tasks_active_device_idx
    ON purchase_tasks (claimed_by_device_id)
    WHERE claimed_by_device_id IS NOT NULL
      AND status IN ('CLAIMED', 'RUNNING', 'WAITING_CONFIRMATION');

CREATE TABLE task_executions (
    id TEXT PRIMARY KEY NOT NULL
        CHECK (length(id) = 36),
    task_id TEXT NOT NULL
        REFERENCES purchase_tasks(id) ON UPDATE RESTRICT ON DELETE CASCADE,
    attempt_no INTEGER NOT NULL
        CHECK (attempt_no > 0),
    claim_generation INTEGER NOT NULL
        CHECK (claim_generation > 0),
    user_id TEXT NOT NULL
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    device_id TEXT NOT NULL
        REFERENCES devices(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    current_step TEXT NOT NULL
        CHECK (
            length(trim(current_step)) > 0
            AND length(CAST(current_step AS BLOB)) <= 64
        ),
    last_heartbeat_at TEXT NOT NULL,
    order_submitted INTEGER NOT NULL DEFAULT 0
        CHECK (order_submitted = 0),
    started_at TEXT NOT NULL,
    finished_at TEXT,
    UNIQUE (task_id, attempt_no),
    UNIQUE (task_id, claim_generation)
);

CREATE UNIQUE INDEX task_executions_active_task_idx
    ON task_executions (task_id)
    WHERE finished_at IS NULL;

CREATE INDEX task_executions_device_heartbeat_idx
    ON task_executions (device_id, last_heartbeat_at DESC);

CREATE TABLE lifecycle_requests (
    user_id TEXT NOT NULL
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    device_id TEXT NOT NULL
        REFERENCES devices(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    operation TEXT NOT NULL
        CHECK (
            operation IN ('CLAIM_NEXT', 'START', 'RELEASE', 'CANCEL_ACK')
        ),
    idempotency_key TEXT NOT NULL
        CHECK (
            length(trim(idempotency_key)) > 0
            AND length(CAST(idempotency_key AS BLOB)) <= 128
        ),
    request_sha256 TEXT NOT NULL
        CHECK (
            length(request_sha256) = 64
            AND request_sha256 NOT GLOB '*[^0-9a-f]*'
        ),
    result_kind TEXT NOT NULL
        CHECK (result_kind IN ('TASK', 'NO_TASK', 'EXECUTION')),
    task_id TEXT
        REFERENCES purchase_tasks(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    claim_generation INTEGER
        CHECK (claim_generation IS NULL OR claim_generation > 0),
    execution_id TEXT
        REFERENCES task_executions(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    created_at TEXT NOT NULL,
    PRIMARY KEY (user_id, device_id, operation, idempotency_key),
    CHECK (
        (
            operation = 'CLAIM_NEXT'
            AND result_kind = 'NO_TASK'
            AND task_id IS NULL
            AND claim_generation IS NULL
            AND execution_id IS NULL
        )
        OR (
            operation = 'CLAIM_NEXT'
            AND result_kind = 'TASK'
            AND task_id IS NOT NULL
            AND claim_generation IS NOT NULL
            AND execution_id IS NULL
        )
        OR (
            operation = 'START'
            AND result_kind = 'EXECUTION'
            AND task_id IS NOT NULL
            AND claim_generation IS NOT NULL
            AND execution_id IS NOT NULL
        )
        OR (
            operation = 'RELEASE'
            AND result_kind = 'TASK'
            AND task_id IS NOT NULL
            AND claim_generation IS NOT NULL
            AND execution_id IS NULL
        )
        OR (
            operation = 'CANCEL_ACK'
            AND result_kind = 'TASK'
            AND task_id IS NOT NULL
            AND claim_generation IS NOT NULL
            AND execution_id IS NOT NULL
        )
    )
);

ALTER TABLE task_events RENAME TO task_events_v3;

CREATE TABLE task_events (
    id TEXT PRIMARY KEY NOT NULL
        CHECK (length(id) = 36),
    task_id TEXT NOT NULL
        REFERENCES purchase_tasks(id) ON UPDATE RESTRICT ON DELETE CASCADE,
    event_type TEXT NOT NULL
        CHECK (
            event_type IN (
                'TASK_CREATED',
                'TASK_CLAIMED',
                'TASK_RECLAIMED',
                'TASK_RELEASED',
                'TASK_STARTED',
                'TASK_CANCEL_REQUESTED',
                'TASK_CANCELED'
            )
        ),
    message TEXT NOT NULL,
    occurred_at TEXT NOT NULL,
    actor_user_id TEXT
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT,
    actor_device_id TEXT
        REFERENCES devices(id) ON UPDATE RESTRICT ON DELETE RESTRICT
);

INSERT INTO task_events (
    id,
    task_id,
    event_type,
    message,
    occurred_at,
    actor_user_id,
    actor_device_id
)
SELECT
    id,
    task_id,
    event_type,
    message,
    occurred_at,
    actor_user_id,
    NULL
FROM task_events_v3;

DROP TABLE task_events_v3;

CREATE INDEX task_events_task_occurred_idx
    ON task_events (task_id, occurred_at ASC, id ASC);

CREATE INDEX task_events_actor_user_idx
    ON task_events (actor_user_id, occurred_at DESC, id DESC);

CREATE INDEX task_events_actor_device_idx
    ON task_events (actor_device_id, occurred_at DESC, id DESC);

-- +goose Down
CREATE TEMP TABLE task_events_v4_down_guard (
    allowed INTEGER NOT NULL
        CHECK (allowed = 1)
);

INSERT INTO task_events_v4_down_guard (allowed)
SELECT CASE
    WHEN EXISTS (
        SELECT 1
        FROM task_events
        WHERE event_type NOT IN ('TASK_CREATED', 'TASK_CANCELED')
           OR actor_device_id IS NOT NULL
    )
    THEN 0
    ELSE 1
END;

DROP TABLE task_events_v4_down_guard;

ALTER TABLE task_events RENAME TO task_events_v4;

CREATE TABLE task_events (
    id TEXT PRIMARY KEY NOT NULL
        CHECK (length(id) = 36),
    task_id TEXT NOT NULL
        REFERENCES purchase_tasks(id) ON UPDATE RESTRICT ON DELETE CASCADE,
    event_type TEXT NOT NULL
        CHECK (event_type IN ('TASK_CREATED', 'TASK_CANCELED')),
    message TEXT NOT NULL,
    occurred_at TEXT NOT NULL,
    actor_user_id TEXT
        REFERENCES users(id) ON UPDATE RESTRICT ON DELETE RESTRICT
);

INSERT INTO task_events (
    id,
    task_id,
    event_type,
    message,
    occurred_at,
    actor_user_id
)
SELECT
    id,
    task_id,
    event_type,
    message,
    occurred_at,
    actor_user_id
FROM task_events_v4;

DROP TABLE task_events_v4;

CREATE INDEX task_events_task_occurred_idx
    ON task_events (task_id, occurred_at ASC, id ASC);

CREATE INDEX task_events_actor_user_idx
    ON task_events (actor_user_id, occurred_at DESC, id DESC);

DROP TABLE lifecycle_requests;
DROP INDEX task_executions_device_heartbeat_idx;
DROP INDEX task_executions_active_task_idx;
DROP TABLE task_executions;
DROP INDEX purchase_tasks_active_device_idx;

ALTER TABLE purchase_tasks DROP COLUMN cancel_requested_by_user_id;
ALTER TABLE purchase_tasks DROP COLUMN cancel_requested_at;
ALTER TABLE purchase_tasks DROP COLUMN claim_expires_at;
ALTER TABLE purchase_tasks DROP COLUMN claim_issued_at;
ALTER TABLE purchase_tasks DROP COLUMN claim_token_hash;
ALTER TABLE purchase_tasks DROP COLUMN claim_generation;
ALTER TABLE purchase_tasks DROP COLUMN claimed_by_device_id;
ALTER TABLE purchase_tasks DROP COLUMN claimed_by_user_id;

ALTER TABLE devices DROP COLUMN readiness_reported_at;
ALTER TABLE devices DROP COLUMN pdd_installed;
ALTER TABLE devices DROP COLUMN accessibility_enabled;