-- Royal Enfield Workflow Management System Database Schema
-- PostgreSQL 16.x
-- Generated from ERD_Mermaid.txt

-- Enable UUID extension
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

-- Create custom types
CREATE TYPE priority_type AS ENUM ('STANDARD', 'EXPRESS');
CREATE TYPE workflow_status AS ENUM ('DRAFT', 'PENDING', 'IN_PROGRESS', 'APPROVED', 'REJECTED', 'CLOSED');
CREATE TYPE approval_status AS ENUM ('PENDING', 'IN_PROGRESS', 'APPROVED', 'REJECTED', 'SKIPPED');
CREATE TYPE participant_type AS ENUM ('SPECTATOR', 'INITIATOR', 'APPROVER', 'CONSULTATION');
CREATE TYPE tat_status AS ENUM ('ON_TRACK', 'APPROACHING', 'BREACHED');
CREATE TYPE notification_priority AS ENUM ('LOW', 'MEDIUM', 'HIGH', 'URGENT');
CREATE TYPE document_category AS ENUM ('SUPPORTING', 'APPROVAL', 'REFERENCE', 'FINAL', 'OTHER');
CREATE TYPE work_note_type AS ENUM ('COMMENT', 'QUESTION', 'CLARIFICATION', 'UPDATE', 'SYSTEM');
CREATE TYPE activity_severity AS ENUM ('INFO', 'WARNING', 'ERROR', 'CRITICAL');
CREATE TYPE setting_type AS ENUM ('STRING', 'NUMBER', 'BOOLEAN', 'JSON', 'ARRAY');

-- Users table
CREATE TABLE users (
    user_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    employee_id VARCHAR(50), -- Optional - HR System Employee ID
    okta_sub VARCHAR(100) UNIQUE NOT NULL, -- Okta subject identifier (unique)
    email VARCHAR(255) UNIQUE NOT NULL, -- Primary identifier for user lookup
    first_name VARCHAR(100), -- Optional
    last_name VARCHAR(100), -- Optional
    display_name VARCHAR(200), -- Optional
    department VARCHAR(100),
    designation VARCHAR(100),
    phone VARCHAR(20),
    location JSONB,
    is_active BOOLEAN DEFAULT true,
    is_admin BOOLEAN DEFAULT false,
    last_login TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Workflow Requests table
CREATE TABLE workflow_requests (
    request_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_number VARCHAR(20) UNIQUE NOT NULL,
    initiator_id UUID NOT NULL REFERENCES users(user_id),
    template_type VARCHAR(20) DEFAULT 'CUSTOM',
    title VARCHAR(500) NOT NULL,
    description TEXT NOT NULL,
    priority priority_type DEFAULT 'STANDARD',
    status workflow_status DEFAULT 'DRAFT',
    current_level INTEGER DEFAULT 1,
    total_levels INTEGER DEFAULT 1 CHECK (total_levels <= 10),
    total_tat_hours DECIMAL(10,2) DEFAULT 0,
    submission_date TIMESTAMP WITH TIME ZONE,
    closure_date TIMESTAMP WITH TIME ZONE,
    conclusion_remark TEXT,
    ai_generated_conclusion TEXT,
    is_draft BOOLEAN DEFAULT true,
    is_deleted BOOLEAN DEFAULT false,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Approval Levels table
CREATE TABLE approval_levels (
    level_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    level_number INTEGER NOT NULL,
    level_name VARCHAR(100),
    approver_id UUID NOT NULL REFERENCES users(user_id),
    approver_email VARCHAR(255) NOT NULL,
    approver_name VARCHAR(200) NOT NULL,
    tat_hours DECIMAL(10,2) NOT NULL,
    tat_days INTEGER GENERATED ALWAYS AS (CEIL(tat_hours / 24)) STORED,
    status approval_status DEFAULT 'PENDING',
    level_start_time TIMESTAMP WITH TIME ZONE,
    level_end_time TIMESTAMP WITH TIME ZONE,
    action_date TIMESTAMP WITH TIME ZONE,
    comments TEXT,
    rejection_reason TEXT,
    is_final_approver BOOLEAN DEFAULT false,
    elapsed_hours DECIMAL(10,2) DEFAULT 0,
    remaining_hours DECIMAL(10,2) GENERATED ALWAYS AS (GREATEST(0, tat_hours - elapsed_hours)) STORED,
    tat_percentage_used DECIMAL(5,2) GENERATED ALWAYS AS (LEAST(100, (elapsed_hours / NULLIF(tat_hours, 0)) * 100)) STORED,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    UNIQUE(request_id, level_number)
);

-- Participants table
CREATE TABLE participants (
    participant_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(user_id),
    user_email VARCHAR(255) NOT NULL,
    user_name VARCHAR(200) NOT NULL,
    participant_type participant_type NOT NULL,
    can_comment BOOLEAN DEFAULT true,
    can_view_documents BOOLEAN DEFAULT true,
    can_download_documents BOOLEAN DEFAULT false,
    notification_enabled BOOLEAN DEFAULT true,
    added_by UUID NOT NULL REFERENCES users(user_id),
    added_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    is_active BOOLEAN DEFAULT true,
    UNIQUE(request_id, user_id)
);

-- Documents table
CREATE TABLE documents (
    document_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    uploaded_by UUID NOT NULL REFERENCES users(user_id),
    file_name VARCHAR(255) NOT NULL,
    original_file_name VARCHAR(255) NOT NULL,
    file_type VARCHAR(100) NOT NULL,
    file_extension VARCHAR(10) NOT NULL,
    file_size BIGINT NOT NULL CHECK (file_size <= 10485760), -- 10MB limit
    file_path VARCHAR(500) NOT NULL,
    storage_url VARCHAR(500),
    mime_type VARCHAR(100) NOT NULL,
    checksum VARCHAR(64) NOT NULL,
    is_google_doc BOOLEAN DEFAULT false,
    google_doc_url VARCHAR(500),
    category document_category DEFAULT 'OTHER',
    version INTEGER DEFAULT 1,
    parent_document_id UUID REFERENCES documents(document_id),
    is_deleted BOOLEAN DEFAULT false,
    download_count INTEGER DEFAULT 0,
    uploaded_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Work Notes table
CREATE TABLE work_notes (
    note_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(user_id),
    user_name VARCHAR(200) NOT NULL,
    user_role VARCHAR(50) NOT NULL,
    message TEXT NOT NULL CHECK (LENGTH(message) <= 2000),
    message_type work_note_type DEFAULT 'COMMENT',
    is_priority BOOLEAN DEFAULT false,
    has_attachment BOOLEAN DEFAULT false,
    parent_note_id UUID REFERENCES work_notes(note_id),
    mentioned_users UUID[],
    reactions JSONB DEFAULT '{}',
    is_edited BOOLEAN DEFAULT false,
    is_deleted BOOLEAN DEFAULT false,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Work Note Attachments table
CREATE TABLE work_note_attachments (
    attachment_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    note_id UUID NOT NULL REFERENCES work_notes(note_id) ON DELETE CASCADE,
    file_name VARCHAR(255) NOT NULL,
    file_type VARCHAR(100) NOT NULL,
    file_size BIGINT NOT NULL,
    file_path VARCHAR(500) NOT NULL,
    storage_url VARCHAR(500),
    is_downloadable BOOLEAN DEFAULT true,
    download_count INTEGER DEFAULT 0,
    uploaded_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Activities table
CREATE TABLE activities (
    activity_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    user_id UUID REFERENCES users(user_id),
    user_name VARCHAR(200),
    activity_type VARCHAR(100) NOT NULL,
    activity_description TEXT NOT NULL,
    activity_category VARCHAR(50),
    severity activity_severity DEFAULT 'INFO',
    metadata JSONB DEFAULT '{}',
    is_system_event BOOLEAN DEFAULT false,
    ip_address INET,
    user_agent TEXT,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Notifications table
CREATE TABLE notifications (
    notification_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(user_id),
    request_id UUID REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    notification_type VARCHAR(100) NOT NULL,
    title VARCHAR(200) NOT NULL,
    message TEXT NOT NULL,
    is_read BOOLEAN DEFAULT false,
    priority notification_priority DEFAULT 'MEDIUM',
    action_url VARCHAR(500),
    action_required BOOLEAN DEFAULT false,
    metadata JSONB DEFAULT '{}',
    sent_via VARCHAR(20)[] DEFAULT '{"IN_APP"}',
    email_sent BOOLEAN DEFAULT false,
    sms_sent BOOLEAN DEFAULT false,
    push_sent BOOLEAN DEFAULT false,
    read_at TIMESTAMP WITH TIME ZONE,
    expires_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- TAT Tracking table
CREATE TABLE tat_tracking (
    tracking_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    level_id UUID REFERENCES approval_levels(level_id) ON DELETE CASCADE,
    tracking_type VARCHAR(20) NOT NULL CHECK (tracking_type IN ('REQUEST', 'LEVEL')),
    tat_status tat_status DEFAULT 'ON_TRACK',
    total_tat_hours DECIMAL(10,2) NOT NULL,
    elapsed_hours DECIMAL(10,2) DEFAULT 0,
    remaining_hours DECIMAL(10,2) GENERATED ALWAYS AS (GREATEST(0, total_tat_hours - elapsed_hours)) STORED,
    percentage_used DECIMAL(5,2) GENERATED ALWAYS AS (LEAST(100, (elapsed_hours / NULLIF(total_tat_hours, 0)) * 100)) STORED,
    threshold_50_breached BOOLEAN DEFAULT false,
    threshold_50_alerted_at TIMESTAMP WITH TIME ZONE,
    threshold_80_breached BOOLEAN DEFAULT false,
    threshold_80_alerted_at TIMESTAMP WITH TIME ZONE,
    threshold_100_breached BOOLEAN DEFAULT false,
    threshold_100_alerted_at TIMESTAMP WITH TIME ZONE,
    alert_count INTEGER DEFAULT 0,
    last_calculated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Conclusion Remarks table
CREATE TABLE conclusion_remarks (
    conclusion_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID NOT NULL REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    ai_generated_remark TEXT,
    ai_model_used VARCHAR(50),
    ai_confidence_score DECIMAL(3,2) CHECK (ai_confidence_score >= 0 AND ai_confidence_score <= 1),
    final_remark TEXT,
    edited_by UUID REFERENCES users(user_id),
    is_edited BOOLEAN DEFAULT false,
    edit_count INTEGER DEFAULT 0,
    approval_summary JSONB DEFAULT '{}',
    document_summary JSONB DEFAULT '{}',
    key_discussion_points TEXT[],
    generated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    finalized_at TIMESTAMP WITH TIME ZONE
);

-- Audit Logs table
CREATE TABLE audit_logs (
    audit_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(user_id),
    entity_type VARCHAR(100) NOT NULL,
    entity_id UUID NOT NULL,
    action VARCHAR(50) NOT NULL,
    action_category VARCHAR(50),
    old_values JSONB,
    new_values JSONB,
    changes_summary TEXT,
    ip_address INET,
    user_agent TEXT,
    session_id VARCHAR(255),
    request_method VARCHAR(10),
    request_url VARCHAR(500),
    response_status INTEGER,
    execution_time_ms INTEGER,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- User Sessions table
CREATE TABLE user_sessions (
    session_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(user_id),
    session_token VARCHAR(500) UNIQUE NOT NULL,
    refresh_token VARCHAR(500) UNIQUE,
    ip_address INET,
    user_agent TEXT,
    device_type VARCHAR(20) DEFAULT 'WEB',
    browser VARCHAR(50),
    os VARCHAR(50),
    login_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    last_activity_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    logout_at TIMESTAMP WITH TIME ZONE,
    expires_at TIMESTAMP WITH TIME ZONE NOT NULL,
    is_active BOOLEAN DEFAULT true,
    logout_reason VARCHAR(100)
);

-- Email Logs table
CREATE TABLE email_logs (
    email_log_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    notification_id UUID REFERENCES notifications(notification_id) ON DELETE CASCADE,
    recipient_email VARCHAR(255) NOT NULL,
    recipient_user_id UUID REFERENCES users(user_id),
    cc_emails TEXT[],
    bcc_emails TEXT[],
    subject VARCHAR(500) NOT NULL,
    body TEXT NOT NULL,
    email_type VARCHAR(50),
    status VARCHAR(20) DEFAULT 'QUEUED',
    send_attempts INTEGER DEFAULT 0,
    sent_at TIMESTAMP WITH TIME ZONE,
    failed_at TIMESTAMP WITH TIME ZONE,
    failure_reason TEXT,
    opened_at TIMESTAMP WITH TIME ZONE,
    clicked_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- SMS Logs table
CREATE TABLE sms_logs (
    sms_log_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    request_id UUID REFERENCES workflow_requests(request_id) ON DELETE CASCADE,
    notification_id UUID REFERENCES notifications(notification_id) ON DELETE CASCADE,
    recipient_phone VARCHAR(20) NOT NULL,
    recipient_user_id UUID REFERENCES users(user_id),
    message TEXT NOT NULL,
    sms_type VARCHAR(50),
    status VARCHAR(20) DEFAULT 'QUEUED',
    send_attempts INTEGER DEFAULT 0,
    sent_at TIMESTAMP WITH TIME ZONE,
    delivered_at TIMESTAMP WITH TIME ZONE,
    failed_at TIMESTAMP WITH TIME ZONE,
    failure_reason TEXT,
    sms_provider VARCHAR(50),
    sms_provider_message_id VARCHAR(100),
    cost DECIMAL(10,4),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- System Settings table
CREATE TABLE system_settings (
    setting_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    setting_key VARCHAR(100) UNIQUE NOT NULL,
    setting_value TEXT NOT NULL,
    setting_type setting_type NOT NULL,
    setting_category VARCHAR(50),
    description TEXT,
    is_editable BOOLEAN DEFAULT true,
    is_sensitive BOOLEAN DEFAULT false,
    validation_rules JSONB,
    default_value TEXT,
    updated_by UUID REFERENCES users(user_id),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Workflow Templates table
CREATE TABLE workflow_templates (
    template_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    template_name VARCHAR(200) NOT NULL,
    template_description TEXT,
    template_category VARCHAR(100),
    approval_levels_config JSONB NOT NULL,
    default_tat_hours DECIMAL(10,2) DEFAULT 24,
    is_active BOOLEAN DEFAULT true,
    usage_count INTEGER DEFAULT 0,
    created_by UUID NOT NULL REFERENCES users(user_id),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Report Cache table
CREATE TABLE report_cache (
    cache_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    report_type VARCHAR(100) NOT NULL,
    report_params JSONB NOT NULL,
    report_data JSONB NOT NULL,
    generated_by UUID NOT NULL REFERENCES users(user_id),
    generated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    expires_at TIMESTAMP WITH TIME ZONE NOT NULL,
    access_count INTEGER DEFAULT 0,
    last_accessed_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Create indexes for better performance
CREATE INDEX idx_users_employee_id ON users(employee_id);
CREATE INDEX idx_users_email ON users(email);
CREATE INDEX idx_users_active ON users(is_active);

CREATE INDEX idx_workflow_requests_initiator ON workflow_requests(initiator_id);
CREATE INDEX idx_workflow_requests_status ON workflow_requests(status);
CREATE INDEX idx_workflow_requests_number ON workflow_requests(request_number);
CREATE INDEX idx_workflow_requests_created ON workflow_requests(created_at);

CREATE INDEX idx_approval_levels_request ON approval_levels(request_id);
CREATE INDEX idx_approval_levels_approver ON approval_levels(approver_id);
CREATE INDEX idx_approval_levels_status ON approval_levels(status);

CREATE INDEX idx_participants_request ON participants(request_id);
CREATE INDEX idx_participants_user ON participants(user_id);
CREATE INDEX idx_participants_type ON participants(participant_type);

CREATE INDEX idx_documents_request ON documents(request_id);
CREATE INDEX idx_documents_uploader ON documents(uploaded_by);
CREATE INDEX idx_documents_category ON documents(category);

CREATE INDEX idx_work_notes_request ON work_notes(request_id);
CREATE INDEX idx_work_notes_user ON work_notes(user_id);
CREATE INDEX idx_work_notes_parent ON work_notes(parent_note_id);

CREATE INDEX idx_activities_request ON activities(request_id);
CREATE INDEX idx_activities_user ON activities(user_id);
CREATE INDEX idx_activities_type ON activities(activity_type);
CREATE INDEX idx_activities_created ON activities(created_at);

CREATE INDEX idx_notifications_user ON notifications(user_id);
CREATE INDEX idx_notifications_request ON notifications(request_id);
CREATE INDEX idx_notifications_read ON notifications(is_read);
CREATE INDEX idx_notifications_type ON notifications(notification_type);

CREATE INDEX idx_tat_tracking_request ON tat_tracking(request_id);
CREATE INDEX idx_tat_tracking_level ON tat_tracking(level_id);
CREATE INDEX idx_tat_tracking_status ON tat_tracking(tat_status);

CREATE INDEX idx_audit_logs_user ON audit_logs(user_id);
CREATE INDEX idx_audit_logs_entity ON audit_logs(entity_type, entity_id);
CREATE INDEX idx_audit_logs_created ON audit_logs(created_at);

CREATE INDEX idx_user_sessions_user ON user_sessions(user_id);
CREATE INDEX idx_user_sessions_token ON user_sessions(session_token);
CREATE INDEX idx_user_sessions_active ON user_sessions(is_active);

-- Create triggers for updated_at timestamps
CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = CURRENT_TIMESTAMP;
    RETURN NEW;
END;
$$ language 'plpgsql';

CREATE TRIGGER update_users_updated_at BEFORE UPDATE ON users FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
CREATE TRIGGER update_workflow_requests_updated_at BEFORE UPDATE ON workflow_requests FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
CREATE TRIGGER update_approval_levels_updated_at BEFORE UPDATE ON approval_levels FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
CREATE TRIGGER update_work_notes_updated_at BEFORE UPDATE ON work_notes FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
CREATE TRIGGER update_system_settings_updated_at BEFORE UPDATE ON system_settings FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
CREATE TRIGGER update_workflow_templates_updated_at BEFORE UPDATE ON workflow_templates FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();