/*
  # OKR Management System - Database Schema
  
  1. New Tables
    - `users` - System users (owner/pm/member roles)
    - `projects` - Project entities with health status
    - `project_members` - Many-to-many relationship for project membership
    - `objectives` - Period-based objectives (O in OKR)
    - `krs` - Key Results with flexible periods
    - `checkins` - Daily progress updates
    - `meetings` - Meeting records with summaries
    - `metrics` - Configurable metrics library
    - `templates` - KR templates library
  
  2. Security
    - RLS disabled for all tables (no-auth system requirement)
    - All tables accessible without authentication
  
  3. Notes
    - All timestamps use timestamptz for timezone support
    - Status fields use text with CHECK constraints
    - JSON fields used for flexible template items
*/

-- Users table
CREATE TABLE IF NOT EXISTS users (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name text NOT NULL,
  role text NOT NULL CHECK (role IN ('owner', 'pm', 'member')),
  avatar_url text,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now()
);

-- Projects table
CREATE TABLE IF NOT EXISTS projects (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name text NOT NULL,
  description text,
  owner_id uuid REFERENCES users(id) ON DELETE SET NULL,
  pm_id uuid REFERENCES users(id) ON DELETE SET NULL,
  project_type text DEFAULT 'general',
  status text NOT NULL DEFAULT 'green' CHECK (status IN ('green', 'yellow', 'red')),
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now()
);

-- Project members junction table
CREATE TABLE IF NOT EXISTS project_members (
  project_id uuid REFERENCES projects(id) ON DELETE CASCADE,
  user_id uuid REFERENCES users(id) ON DELETE CASCADE,
  PRIMARY KEY (project_id, user_id)
);

-- Objectives table (period-based goals)
CREATE TABLE IF NOT EXISTS objectives (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  project_id uuid NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  title text NOT NULL,
  description text,
  period_start date NOT NULL,
  period_end date NOT NULL,
  created_by uuid REFERENCES users(id) ON DELETE SET NULL,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now(),
  CONSTRAINT valid_period CHECK (period_end >= period_start)
);

-- Key Results table
CREATE TABLE IF NOT EXISTS krs (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  project_id uuid NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  objective_id uuid REFERENCES objectives(id) ON DELETE SET NULL,
  period_type text NOT NULL DEFAULT 'custom' CHECK (period_type IN ('custom', '3d', '1w', '2w', 'monthly')),
  period_name text,
  period_start date NOT NULL,
  period_end date NOT NULL,
  title text NOT NULL,
  metric_name text NOT NULL,
  unit text NOT NULL,
  direction text NOT NULL DEFAULT 'increase' CHECK (direction IN ('increase', 'decrease')),
  target_value numeric NOT NULL CHECK (target_value > 0),
  current_value numeric NOT NULL DEFAULT 0,
  owner_user_id uuid REFERENCES users(id) ON DELETE SET NULL,
  confidence integer NOT NULL DEFAULT 80 CHECK (confidence >= 0 AND confidence <= 100),
  status text NOT NULL DEFAULT 'green' CHECK (status IN ('green', 'yellow', 'red')),
  reason_code text CHECK (reason_code IS NULL OR reason_code IN ('RESOURCE', 'DEPENDENCY', 'DECISION', 'SCOPE', 'EXECUTION', 'OTHER')),
  note text,
  need_owner_help boolean NOT NULL DEFAULT false,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now(),
  CONSTRAINT valid_kr_period CHECK (period_end >= period_start)
);

-- Checkins table
CREATE TABLE IF NOT EXISTS checkins (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  kr_id uuid NOT NULL REFERENCES krs(id) ON DELETE CASCADE,
  project_id uuid NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  user_id uuid REFERENCES users(id) ON DELETE SET NULL,
  date date NOT NULL DEFAULT CURRENT_DATE,
  current_value numeric NOT NULL,
  delta_value numeric,
  confidence integer NOT NULL CHECK (confidence >= 0 AND confidence <= 100),
  status_snapshot text NOT NULL CHECK (status_snapshot IN ('green', 'yellow', 'red')),
  reason_code text CHECK (reason_code IS NULL OR reason_code IN ('RESOURCE', 'DEPENDENCY', 'DECISION', 'SCOPE', 'EXECUTION', 'OTHER')),
  note text,
  created_at timestamptz DEFAULT now()
);

-- Meetings table
CREATE TABLE IF NOT EXISTS meetings (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  project_id uuid NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  period_start date NOT NULL,
  period_end date NOT NULL,
  summary text NOT NULL,
  decisions text,
  risks text,
  next_period_commitments text,
  created_by uuid REFERENCES users(id) ON DELETE SET NULL,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now()
);

-- Metrics library table
CREATE TABLE IF NOT EXISTS metrics (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name text NOT NULL,
  unit text NOT NULL,
  direction text NOT NULL DEFAULT 'increase' CHECK (direction IN ('increase', 'decrease')),
  category text,
  is_active boolean NOT NULL DEFAULT true,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now()
);

-- Templates library table
CREATE TABLE IF NOT EXISTS templates (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name text NOT NULL,
  description text,
  project_type text,
  tags jsonb DEFAULT '[]'::jsonb,
  items jsonb NOT NULL DEFAULT '[]'::jsonb,
  is_active boolean NOT NULL DEFAULT true,
  created_at timestamptz DEFAULT now(),
  updated_at timestamptz DEFAULT now()
);

-- Create indexes for better query performance
CREATE INDEX IF NOT EXISTS idx_projects_owner ON projects(owner_id);
CREATE INDEX IF NOT EXISTS idx_projects_pm ON projects(pm_id);
CREATE INDEX IF NOT EXISTS idx_projects_status ON projects(status);
CREATE INDEX IF NOT EXISTS idx_objectives_project ON objectives(project_id);
CREATE INDEX IF NOT EXISTS idx_objectives_period ON objectives(period_start, period_end);
CREATE INDEX IF NOT EXISTS idx_krs_project ON krs(project_id);
CREATE INDEX IF NOT EXISTS idx_krs_objective ON krs(objective_id);
CREATE INDEX IF NOT EXISTS idx_krs_owner ON krs(owner_user_id);
CREATE INDEX IF NOT EXISTS idx_krs_status ON krs(status);
CREATE INDEX IF NOT EXISTS idx_krs_period ON krs(period_start, period_end);
CREATE INDEX IF NOT EXISTS idx_checkins_kr ON checkins(kr_id);
CREATE INDEX IF NOT EXISTS idx_checkins_date ON checkins(date);
CREATE INDEX IF NOT EXISTS idx_meetings_project ON meetings(project_id);
CREATE INDEX IF NOT EXISTS idx_metrics_active ON metrics(is_active);
CREATE INDEX IF NOT EXISTS idx_templates_active ON templates(is_active);