-- sql/init.sql
-- Initialize PostgreSQL database for Project Defrag

-- Enable useful extensions
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
CREATE EXTENSION IF NOT EXISTS "pgcrypto";

-- Files table
CREATE TABLE IF NOT EXISTS files (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    path TEXT NOT NULL,
    size BIGINT NOT NULL,
    modified_time TIMESTAMP WITH TIME ZONE,
    created_time TIMESTAMP WITH TIME ZONE,
    file_hash VARCHAR(64),  -- SHA-256 hash
    category VARCHAR(50),
    disk_label VARCHAR(50),
    last_verified TIMESTAMP WITH TIME ZONE,

    -- Metadata
    metadata JSONB DEFAULT '{}',

    -- Audit fields
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,

    -- Constraints
    CONSTRAINT unique_file_path UNIQUE(path)
);

-- Operations table (audit log)
CREATE TABLE IF NOT EXISTS operations (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    operation_type VARCHAR(50) NOT NULL,
    source_path TEXT,
    target_path TEXT,
    status VARCHAR(20) NOT NULL,

    -- File reference
    file_id UUID REFERENCES files(id) ON DELETE SET NULL,

    -- Performance metrics
    duration_ms INTEGER,
    bytes_processed BIGINT,

    -- Error information
    error_message TEXT,
    error_details JSONB,

    -- Context
    session_id VARCHAR(100),
    user_agent TEXT,

    -- Audit fields
    started_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    completed_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Deduplication hash store
CREATE TABLE IF NOT EXISTS deduplication_store (
    hash VARCHAR(64) PRIMARY KEY,
    canonical_path TEXT NOT NULL,
    reference_count INTEGER DEFAULT 1,
    first_seen TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    last_seen TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- Migration plan table
CREATE TABLE IF NOT EXISTS migration_plans (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    name VARCHAR(100) NOT NULL,
    source_disk VARCHAR(50) NOT NULL,
    target_disk VARCHAR(50) NOT NULL,
    plan_json JSONB NOT NULL,

    -- Statistics
    total_files INTEGER DEFAULT 0,
    total_size BIGINT DEFAULT 0,
    estimated_duration INTEGER,  -- in seconds

    -- Status
    status VARCHAR(20) DEFAULT 'draft',

    -- Audit
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    executed_at TIMESTAMP WITH TIME ZONE,
    completed_at TIMESTAMP WITH TIME ZONE
);

-- Indexes for performance
CREATE INDEX IF NOT EXISTS idx_files_path ON files(path);
CREATE INDEX IF NOT EXISTS idx_files_hash ON files(file_hash);
CREATE INDEX IF NOT EXISTS idx_files_disk ON files(disk_label);
CREATE INDEX IF NOT EXISTS idx_files_category ON files(category);

CREATE INDEX IF NOT EXISTS idx_operations_status ON operations(status);
CREATE INDEX IF NOT EXISTS idx_operations_created ON operations(created_at);
CREATE INDEX IF NOT EXISTS idx_operations_file_id ON operations(file_id);

CREATE INDEX IF NOT EXISTS idx_dedup_canonical ON deduplication_store(canonical_path);

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

-- Triggers for automatic updated_at
CREATE TRIGGER update_files_updated_at BEFORE UPDATE ON files
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

-- View for operational dashboard
CREATE OR REPLACE VIEW operational_dashboard AS
SELECT
    o.status,
    COUNT(*) as operation_count,
    SUM(o.bytes_processed) as total_bytes,
    AVG(o.duration_ms) as avg_duration_ms,
    MIN(o.started_at) as earliest_operation,
    MAX(o.completed_at) as latest_operation
FROM operations o
WHERE o.started_at > CURRENT_TIMESTAMP - INTERVAL '24 hours'
GROUP BY o.status;

-- View for disk usage statistics
CREATE OR REPLACE VIEW disk_usage_stats AS
SELECT
    disk_label,
    COUNT(*) as file_count,
    SUM(size) as total_size,
    AVG(size) as avg_file_size,
    MIN(created_time) as oldest_file,
    MAX(modified_time) as newest_file
FROM files
GROUP BY disk_label;

-- Insert default configuration
INSERT INTO migration_plans (name, source_disk, target_disk, plan_json, status)
VALUES (
    'Default Migration Plan',
    'disk_d',
    'disk_e',
    '{"strategy": "hardlink", "verify_copies": true, "preserve_timestamps": true}'::jsonb,
    'draft'
) ON CONFLICT DO NOTHING;

-- Create read-only user for monitoring
DO $$
BEGIN
    IF NOT EXISTS (SELECT FROM pg_catalog.pg_roles WHERE rolname = 'monitor_user') THEN
        CREATE USER monitor_user WITH PASSWORD 'monitor_password';
    END IF;
END
$$;

GRANT CONNECT ON DATABASE disk_reorganizer_db TO monitor_user;
GRANT USAGE ON SCHEMA public TO monitor_user;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO monitor_user;
GRANT SELECT ON operational_dashboard TO monitor_user;
GRANT SELECT ON disk_usage_stats TO monitor_user;