-- Migration 039: Multi-Projekt-Architektur
-- Enables multiple compliance projects per tenant (Cloud-Ready Multi-Tenancy)
--
-- Changes:
-- 1. New table compliance_projects (project metadata)
-- 2. sdk_states: Drop UNIQUE(tenant_id), add project_id column with FK
-- 3. Migrate existing data: Create default project for each existing sdk_states row

-- =============================================================================
-- 1. New table: compliance_projects
-- =============================================================================

CREATE TABLE IF NOT EXISTS compliance_projects (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id VARCHAR(255) NOT NULL,
    name VARCHAR(500) NOT NULL,
    description TEXT DEFAULT '',
    customer_type VARCHAR(20) DEFAULT 'new',       -- 'new' | 'existing'
    status VARCHAR(20) DEFAULT 'active',            -- 'active' | 'archived' | 'deleted'
    project_version INTEGER DEFAULT 1,
    completion_percentage INTEGER DEFAULT 0,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    archived_at TIMESTAMPTZ
);

CREATE INDEX IF NOT EXISTS idx_compliance_projects_tenant ON compliance_projects(tenant_id);
CREATE INDEX IF NOT EXISTS idx_compliance_projects_status ON compliance_projects(tenant_id, status);

-- =============================================================================
-- 2. sdk_states: Add project_id, adjust constraints
-- Only runs if sdk_states table exists (it may not yet exist if no state
-- has been saved via the frontend state API)
-- =============================================================================

DO $$
BEGIN
    -- Check if sdk_states exists
    IF EXISTS (
        SELECT 1 FROM information_schema.tables
        WHERE table_name = 'sdk_states'
    ) THEN
        -- Drop the old UNIQUE constraint on tenant_id (allows multiple states per tenant)
        ALTER TABLE sdk_states DROP CONSTRAINT IF EXISTS sdk_states_tenant_id_key;

        -- Add project_id column (nullable initially for migration)
        ALTER TABLE sdk_states ADD COLUMN IF NOT EXISTS project_id UUID;

        -- =====================================================================
        -- 3. Data migration: Create default projects for existing states
        -- =====================================================================

        -- For each existing sdk_states row without a project, create a default project
        INSERT INTO compliance_projects (id, tenant_id, name, customer_type, status)
        SELECT
            gen_random_uuid(),
            s.tenant_id,
            COALESCE(s.state->'companyProfile'->>'companyName', 'Projekt 1'),
            COALESCE(s.state->>'customerType', 'new'),
            'active'
        FROM sdk_states s
        WHERE s.project_id IS NULL
        ON CONFLICT DO NOTHING;

        -- Link existing states to their newly created projects
        UPDATE sdk_states s
        SET project_id = p.id
        FROM compliance_projects p
        WHERE s.tenant_id = p.tenant_id AND s.project_id IS NULL;

        -- =====================================================================
        -- 4. Add constraints after migration
        -- =====================================================================

        -- Make project_id NOT NULL if all rows have a value
        IF NOT EXISTS (SELECT 1 FROM sdk_states WHERE project_id IS NULL) THEN
            ALTER TABLE sdk_states ALTER COLUMN project_id SET NOT NULL;
        END IF;

        -- Unique constraint: one state per (tenant, project)
        IF NOT EXISTS (
            SELECT 1 FROM pg_constraint WHERE conname = 'uq_sdk_states_tenant_project'
        ) THEN
            ALTER TABLE sdk_states ADD CONSTRAINT uq_sdk_states_tenant_project
                UNIQUE (tenant_id, project_id);
        END IF;

        -- Foreign key to compliance_projects
        IF NOT EXISTS (
            SELECT 1 FROM pg_constraint WHERE conname = 'fk_sdk_states_project'
        ) THEN
            ALTER TABLE sdk_states ADD CONSTRAINT fk_sdk_states_project
                FOREIGN KEY (project_id) REFERENCES compliance_projects(id) ON DELETE CASCADE;
        END IF;

        RAISE NOTICE 'sdk_states migration completed successfully';
    ELSE
        RAISE NOTICE 'sdk_states table does not exist yet — skipping sdk_states migration (will be applied on first state save)';
    END IF;
END $$;