-- Medical AI Platform Database Schema
-- This is the ONLY schema file you need to run
-- Run this in Supabase SQL Editor

-- ============================================================================
-- STEP 1: Enable required extensions
-- ============================================================================

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
CREATE EXTENSION IF NOT EXISTS "vector";

-- ============================================================================
-- STEP 2: Create all tables
-- ============================================================================

-- Users table
CREATE TABLE IF NOT EXISTS public.users (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  email TEXT UNIQUE NOT NULL,
  name TEXT,
  plan TEXT NOT NULL DEFAULT 'free' CHECK (plan IN ('free', 'student', 'pro', 'admin')),
  role TEXT CHECK (role IN ('super_admin', 'admin', 'ops', 'support', 'viewer')),
  personal_api_key TEXT,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  disabled BOOLEAN NOT NULL DEFAULT FALSE
);

-- Admin allowlist table
CREATE TABLE IF NOT EXISTS public.admin_allowlist (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  email TEXT UNIQUE NOT NULL,
  role TEXT NOT NULL CHECK (role IN ('super_admin', 'admin', 'ops', 'support', 'viewer')),
  added_by UUID REFERENCES public.users(id),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Usage counters table
CREATE TABLE IF NOT EXISTS public.usage_counters (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  date DATE NOT NULL DEFAULT CURRENT_DATE,
  tokens_used INTEGER NOT NULL DEFAULT 0,
  requests_count INTEGER NOT NULL DEFAULT 0,
  pdf_uploads INTEGER NOT NULL DEFAULT 0,
  mcqs_generated INTEGER NOT NULL DEFAULT 0,
  images_used INTEGER NOT NULL DEFAULT 0,
  flashcards_generated INTEGER NOT NULL DEFAULT 0,
  UNIQUE(user_id, date)
);

-- API keys table
CREATE TABLE IF NOT EXISTS public.api_keys (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  provider TEXT NOT NULL,
  feature TEXT NOT NULL,
  key_value TEXT NOT NULL,
  priority INTEGER NOT NULL DEFAULT 0,
  status TEXT NOT NULL DEFAULT 'active' CHECK (status IN ('active', 'degraded', 'disabled')),
  failure_count INTEGER NOT NULL DEFAULT 0,
  last_used_at TIMESTAMPTZ,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Provider health table
CREATE TABLE IF NOT EXISTS public.provider_health (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  api_key_id UUID NOT NULL REFERENCES public.api_keys(id) ON DELETE CASCADE,
  checked_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  status TEXT NOT NULL CHECK (status IN ('healthy', 'degraded', 'failed')),
  response_time_ms INTEGER,
  error_message TEXT,
  quota_remaining INTEGER
);

-- System flags table
CREATE TABLE IF NOT EXISTS public.system_flags (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  flag_name TEXT UNIQUE NOT NULL,
  flag_value TEXT NOT NULL,
  updated_by UUID REFERENCES public.users(id),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Documents table
CREATE TABLE IF NOT EXISTS public.documents (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  filename TEXT NOT NULL,
  file_type TEXT NOT NULL CHECK (file_type IN ('pdf', 'image')),
  file_size INTEGER NOT NULL,
  storage_path TEXT NOT NULL,
  processing_status TEXT NOT NULL DEFAULT 'pending' CHECK (processing_status IN ('pending', 'processing', 'completed', 'failed')),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Embeddings table
CREATE TABLE IF NOT EXISTS public.embeddings (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  document_id UUID NOT NULL REFERENCES public.documents(id) ON DELETE CASCADE,
  chunk_text TEXT NOT NULL,
  chunk_index INTEGER NOT NULL,
  embedding VECTOR(768),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Chat sessions table
CREATE TABLE IF NOT EXISTS public.chat_sessions (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  title TEXT,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Messages table
CREATE TABLE IF NOT EXISTS public.messages (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  session_id UUID NOT NULL REFERENCES public.chat_sessions(id) ON DELETE CASCADE,
  role TEXT NOT NULL CHECK (role IN ('user', 'assistant', 'system')),
  content TEXT NOT NULL,
  tokens_used INTEGER,
  citations JSONB,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Study sessions table
CREATE TABLE IF NOT EXISTS public.study_sessions (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  topic TEXT NOT NULL,
  duration INTEGER NOT NULL,
  scheduled_date TIMESTAMPTZ,
  notes TEXT,
  status TEXT NOT NULL DEFAULT 'planned' CHECK (status IN ('planned', 'in_progress', 'completed', 'cancelled')),
  completed_at TIMESTAMPTZ,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Subscriptions table
CREATE TABLE IF NOT EXISTS public.subscriptions (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  plan TEXT NOT NULL CHECK (plan IN ('free', 'student', 'pro', 'admin')),
  razorpay_subscription_id TEXT UNIQUE,
  status TEXT NOT NULL CHECK (status IN ('active', 'cancelled', 'expired')),
  current_period_start TIMESTAMPTZ,
  current_period_end TIMESTAMPTZ,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Payments table
CREATE TABLE IF NOT EXISTS public.payments (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  user_id UUID NOT NULL REFERENCES public.users(id) ON DELETE CASCADE,
  subscription_id UUID REFERENCES public.subscriptions(id),
  razorpay_payment_id TEXT UNIQUE,
  amount INTEGER NOT NULL,
  currency TEXT NOT NULL DEFAULT 'INR',
  status TEXT NOT NULL CHECK (status IN ('success', 'failed', 'pending')),
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Audit logs table
CREATE TABLE IF NOT EXISTS public.audit_logs (
  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  admin_id UUID REFERENCES public.users(id),
  action_type TEXT NOT NULL,
  target_type TEXT,
  target_id TEXT,
  details JSONB,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ============================================================================
-- STEP 3: Create indexes
-- ============================================================================

CREATE INDEX IF NOT EXISTS idx_users_email ON public.users(email);
CREATE INDEX IF NOT EXISTS idx_admin_allowlist_email ON public.admin_allowlist(email);
CREATE INDEX IF NOT EXISTS idx_usage_counters_user_date ON public.usage_counters(user_id, date);
CREATE INDEX IF NOT EXISTS idx_api_keys_provider_feature ON public.api_keys(provider, feature);
CREATE INDEX IF NOT EXISTS idx_chat_sessions_user_id ON public.chat_sessions(user_id);
CREATE INDEX IF NOT EXISTS idx_messages_session_created ON public.messages(session_id, created_at);
CREATE INDEX IF NOT EXISTS idx_documents_user_id ON public.documents(user_id);
CREATE INDEX IF NOT EXISTS idx_audit_logs_admin_created ON public.audit_logs(admin_id, created_at DESC);

-- ============================================================================
-- STEP 4: Create trigger for updated_at
-- ============================================================================

CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = NOW();
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

DROP TRIGGER IF EXISTS update_users_updated_at ON public.users;
CREATE TRIGGER update_users_updated_at BEFORE UPDATE ON public.users
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

DROP TRIGGER IF EXISTS update_chat_sessions_updated_at ON public.chat_sessions;
CREATE TRIGGER update_chat_sessions_updated_at BEFORE UPDATE ON public.chat_sessions
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

-- ============================================================================
-- DONE!
-- ============================================================================

SELECT 'Schema created successfully!' as status;