import db from "../db.js";

/**
 * Log a field change to the history table
 */
export function logFieldChange(tableName, recordId, fieldName, oldValue, newValue, changedBy = null, reason = null) {
	// Don't log if values are the same
	if (oldValue === newValue) return null;

	const stmt = db.prepare(`
		INSERT INTO field_change_history 
		(table_name, record_id, field_name, old_value, new_value, changed_by, change_reason)
		VALUES (?, ?, ?, ?, ?, ?, ?)
	`);

	return stmt.run(
		tableName,
		recordId,
		fieldName,
		oldValue || null,
		newValue || null,
		changedBy,
		reason
	);
}

/**
 * Get field change history for a specific field
 */
export function getFieldHistory(tableName, recordId, fieldName) {
	const stmt = db.prepare(`
		SELECT 
			fch.*,
			u.name as changed_by_name,
			u.username as changed_by_username
		FROM field_change_history fch
		LEFT JOIN users u ON fch.changed_by = u.id
		WHERE fch.table_name = ? AND fch.record_id = ? AND fch.field_name = ?
		ORDER BY fch.changed_at DESC
	`);

	return stmt.all(tableName, recordId, fieldName);
}

/**
 * Get all field changes for a specific record
 */
export function getAllFieldHistory(tableName, recordId) {
	const stmt = db.prepare(`
		SELECT 
			fch.*,
			u.name as changed_by_name,
			u.username as changed_by_username
		FROM field_change_history fch
		LEFT JOIN users u ON fch.changed_by = u.id
		WHERE fch.table_name = ? AND fch.record_id = ?
		ORDER BY fch.changed_at DESC, fch.field_name ASC
	`);

	return stmt.all(tableName, recordId);
}

/**
 * Check if a field has any change history
 */
export function hasFieldHistory(tableName, recordId, fieldName) {
	const stmt = db.prepare(`
		SELECT COUNT(*) as count
		FROM field_change_history 
		WHERE table_name = ? AND record_id = ? AND field_name = ?
	`);

	const result = stmt.get(tableName, recordId, fieldName);
	return result.count > 0;
}

/**
 * Get the most recent change for a field
 */
export function getLatestFieldChange(tableName, recordId, fieldName) {
	const stmt = db.prepare(`
		SELECT 
			fch.*,
			u.name as changed_by_name,
			u.username as changed_by_username
		FROM field_change_history fch
		LEFT JOIN users u ON fch.changed_by = u.id
		WHERE fch.table_name = ? AND fch.record_id = ? AND fch.field_name = ?
		ORDER BY fch.changed_at DESC
		LIMIT 1
	`);

	return stmt.get(tableName, recordId, fieldName);
}