-- Kanban Labels System
-- Adds label/tag support to kanban cards for categorization and filtering

-- Labels table (org-scoped)
CREATE TABLE IF NOT EXISTS kanban_labels (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    org_id UUID NOT NULL REFERENCES organizations(id) ON DELETE CASCADE,
    name TEXT NOT NULL,
    color TEXT NOT NULL DEFAULT '#6366f1',
    created_at TIMESTAMPTZ DEFAULT now(),
    UNIQUE(org_id, name)
);

-- Card-Label junction table (many-to-many)
CREATE TABLE IF NOT EXISTS card_labels (
    card_id UUID NOT NULL REFERENCES kanban_cards(id) ON DELETE CASCADE,
    label_id UUID NOT NULL REFERENCES kanban_labels(id) ON DELETE CASCADE,
    created_at TIMESTAMPTZ DEFAULT now(),
    PRIMARY KEY (card_id, label_id)
);

-- Enable RLS
ALTER TABLE kanban_labels ENABLE ROW LEVEL SECURITY;
ALTER TABLE card_labels ENABLE ROW LEVEL SECURITY;

-- Labels accessible to org members
CREATE POLICY "Labels accessible to org members" ON kanban_labels
    FOR ALL USING (
        EXISTS (
            SELECT 1 FROM org_members m
            WHERE m.org_id = kanban_labels.org_id
            AND m.user_id = auth.uid()
        )
    );

-- Card labels inherit card access
CREATE POLICY "Card labels inherit card access" ON card_labels
    FOR ALL USING (
        EXISTS (
            SELECT 1 FROM kanban_cards c
            JOIN kanban_columns col ON c.column_id = col.id
            JOIN kanban_boards b ON col.board_id = b.id
            JOIN org_members m ON b.org_id = m.org_id
            WHERE c.id = card_labels.card_id
            AND m.user_id = auth.uid()
        )
    );

-- Indexes for performance
CREATE INDEX IF NOT EXISTS idx_kanban_labels_org ON kanban_labels(org_id);
CREATE INDEX IF NOT EXISTS idx_card_labels_card ON card_labels(card_id);
CREATE INDEX IF NOT EXISTS idx_card_labels_label ON card_labels(label_id);

-- Seed default labels for existing organizations
INSERT INTO kanban_labels (org_id, name, color)
SELECT DISTINCT o.id, label.name, label.color
FROM organizations o
CROSS JOIN (
    VALUES 
        ('Bug', '#ef4444'),
        ('Feature', '#22c55e'),
        ('Enhancement', '#3b82f6'),
        ('Documentation', '#a855f7'),
        ('Urgent', '#f97316')
) AS label(name, color)
ON CONFLICT (org_id, name) DO NOTHING;