-- t-paliad-149 PR 1: per-user project pins.
--
-- Design: docs/design-projects-page-2026-05-07.md §4.7 (godel,
-- m-locked 2026-05-07).
--
-- Stores per-user pinned projects. A user pins a project to mark it
-- as a favourite for the /projects page (chip "Angepinnt" filters
-- the tree to pinned-only; star marker on every row toggles state).
--
-- RLS scopes every operation to the calling user — pins are personal
-- working state, not project-team metadata. There is no cross-user
-- visibility in v1; no global_admin override.
--
-- ON DELETE CASCADE on both FKs: project deletion removes pin rows;
-- user deletion removes their pins. No referential drift possible.
--
-- Sections:
--   1. CREATE paliad.user_pinned_projects (with RLS).
--   2. Indexes.

-- ============================================================================
-- 1. paliad.user_pinned_projects
-- ============================================================================

CREATE TABLE paliad.user_pinned_projects (
    user_id    uuid        NOT NULL REFERENCES paliad.users(id)    ON DELETE CASCADE,
    project_id uuid        NOT NULL REFERENCES paliad.projects(id) ON DELETE CASCADE,
    pinned_at  timestamptz NOT NULL DEFAULT now(),
    PRIMARY KEY (user_id, project_id)
);

-- ============================================================================
-- 2. Indexes
-- ============================================================================

-- Hot path: list pins for a user, most-recently-pinned first. The PK
-- already covers (user_id, project_id), but a separate index ordered
-- by pinned_at DESC keeps the "Angepinnt" filter chip fast even as a
-- user accumulates many pins.
CREATE INDEX user_pinned_projects_user_idx
    ON paliad.user_pinned_projects (user_id, pinned_at DESC);

-- ============================================================================
-- 3. RLS
-- ============================================================================

ALTER TABLE paliad.user_pinned_projects ENABLE ROW LEVEL SECURITY;

-- Owner-only access. No global_admin override.
CREATE POLICY user_pinned_projects_owner_all
    ON paliad.user_pinned_projects FOR ALL
    USING (user_id = auth.uid())
    WITH CHECK (user_id = auth.uid());