-- V17: Enhanced Sharing System
-- Replaces simple share_links with comprehensive sharing capabilities

-- Enhanced shares table
CREATE TABLE shares (
    id TEXT PRIMARY KEY NOT NULL,
    target_type TEXT NOT NULL CHECK (target_type IN ('media', 'collection', 'tag', 'saved_search')),
    target_id TEXT NOT NULL,
    owner_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    recipient_type TEXT NOT NULL CHECK (recipient_type IN ('public_link', 'user', 'group', 'federated')),
    recipient_user_id TEXT REFERENCES users(id) ON DELETE CASCADE,
    recipient_group_id TEXT,
    recipient_federated_handle TEXT,
    recipient_federated_server TEXT,
    public_token TEXT UNIQUE,
    public_password_hash TEXT,
    perm_view BOOLEAN NOT NULL DEFAULT TRUE,
    perm_download BOOLEAN NOT NULL DEFAULT FALSE,
    perm_edit BOOLEAN NOT NULL DEFAULT FALSE,
    perm_delete BOOLEAN NOT NULL DEFAULT FALSE,
    perm_reshare BOOLEAN NOT NULL DEFAULT FALSE,
    perm_add BOOLEAN NOT NULL DEFAULT FALSE,
    note TEXT,
    expires_at TIMESTAMPTZ,
    access_count BIGINT NOT NULL DEFAULT 0,
    last_accessed TIMESTAMPTZ,
    inherit_to_children BOOLEAN NOT NULL DEFAULT TRUE,
    parent_share_id TEXT REFERENCES shares(id) ON DELETE CASCADE,
    created_at TIMESTAMPTZ NOT NULL,
    updated_at TIMESTAMPTZ NOT NULL,
    UNIQUE(owner_id, target_type, target_id, recipient_type, recipient_user_id)
);

CREATE INDEX idx_shares_owner ON shares(owner_id);
CREATE INDEX idx_shares_recipient_user ON shares(recipient_user_id);
CREATE INDEX idx_shares_target ON shares(target_type, target_id);
CREATE INDEX idx_shares_token ON shares(public_token);
CREATE INDEX idx_shares_expires ON shares(expires_at);

-- Share activity log
CREATE TABLE share_activity (
    id TEXT PRIMARY KEY NOT NULL,
    share_id TEXT NOT NULL REFERENCES shares(id) ON DELETE CASCADE,
    actor_id TEXT REFERENCES users(id) ON DELETE SET NULL,
    actor_ip TEXT,
    action TEXT NOT NULL,
    details TEXT,
    timestamp TIMESTAMPTZ NOT NULL
);

CREATE INDEX idx_share_activity_share ON share_activity(share_id);
CREATE INDEX idx_share_activity_timestamp ON share_activity(timestamp);

-- Share notifications
CREATE TABLE share_notifications (
    id TEXT PRIMARY KEY NOT NULL,
    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    share_id TEXT NOT NULL REFERENCES shares(id) ON DELETE CASCADE,
    notification_type TEXT NOT NULL,
    is_read BOOLEAN NOT NULL DEFAULT FALSE,
    created_at TIMESTAMPTZ NOT NULL
);

CREATE INDEX idx_share_notifications_user ON share_notifications(user_id);
CREATE INDEX idx_share_notifications_unread ON share_notifications(user_id) WHERE is_read = FALSE;

-- Migrate existing share_links to new shares table
DO $$
BEGIN
    IF EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'share_links') THEN
        INSERT INTO shares (
            id, target_type, target_id, owner_id, recipient_type,
            public_token, public_password_hash, perm_view, perm_download,
            access_count, expires_at, created_at, updated_at
        )
        SELECT
            id, 'media', media_id, created_by, 'public_link',
            token, password_hash, TRUE, TRUE,
            view_count, expires_at, created_at, created_at
        FROM share_links
        ON CONFLICT DO NOTHING;
    END IF;
END $$;