// Vibe coded since I needed more resources on my VPS :/

const Database = require('better-sqlite3');

// 1. Connect to the file (creates it if missing)
const db = new Database('project.db');
db.pragma('journal_mode = WAL'); // Faster, safer writes

class FakeMssqlRequest {
    constructor(db) {
        this.db = db;
        this.params = {}; // Stores your inputs: .input('id', 123)
    }

    // Mimic the .input() method
    // We ignore 'type' because SQLite is loosely typed
    input(name, type, value) {
        // Handle case where value is passed as 2nd arg (omitting type)
        if (value === undefined) value = type; 
        
        this.params[name] = value;
        return this; // Return 'this' to allow chaining (.input().input())
    }

    // Mimic the .query() method
    async query(sqlString) {
        try {
            let cleanSql = sqlString;

            // --- FIX 1: Handle TOP -> LIMIT ---
            // Regex detects: SELECT TOP (@amount) ... OR SELECT TOP 10 ...
            // It captures the value (@amount or 10)
            const topRegex = /SELECT\s+TOP\s*\(?(@?\w+)\)?/i;
            const topMatch = cleanSql.match(topRegex);

            if (topMatch) {
                const limitValue = topMatch[1]; // Extracts '@amount' or '10'
                
                // 1. Remove "TOP (@amount)" from the start
                cleanSql = cleanSql.replace(topRegex, 'SELECT ');
                
                // 2. Remove any trailing semicolon so we can append
                cleanSql = cleanSql.replace(/;\s*$/, '');

                // 3. Append LIMIT to the end
                cleanSql += ` LIMIT ${limitValue}`;
            }

            // 1. Compatibility Fixes (Optional but helpful)
            // Replace 'GETDATE()' with SQLite's "datetime('now')"
            cleanSql = cleanSql.replace(/GETDATE\(\)/gi, "datetime('now', 'localtime')")
            // MS SQL: SYSUTCDATETIME() -> SQLite: datetime('now') (Already UTC)
                .replace(/SYSUTCDATETIME\(\)/gi, "datetime('now')")
            // --- FIX 3: Clean up Square Brackets ---
                .replace(/\[/g, '"').replace(/\]/g, '"')

                // --- FIX 4: Handle String Concatenation in LIKE clauses ---
                // MSSQL: LIKE '%' + @param + '%'
                // SQLite: LIKE '%' || @param || '%'
                // This regex looks for: LIKE '%' + @anything + '%'
                .replace(/LIKE\s+'%'\s*\+\s*(@\w+)\s*\+\s*'%'/gi, "LIKE '%' || $1 || '%'");
            // 2. Determine if it's a SELECT or INSERT/UPDATE
            const stmt = this.db.prepare(cleanSql);
            
            if (cleanSql.trim().toUpperCase().startsWith('SELECT')) {
                // READ: Use .all()
                const rows = stmt.all(this.params);
                return { recordset: rows, rowsAffected: [rows.length] };
            } else {
                // WRITE: Use .run()
                const info = stmt.run(this.params);
                return { recordset: [], rowsAffected: [info.changes] };
            }
        } catch (err) {
            console.error("SQLite Error:", err.message);
            console.error("Query was:", sqlString);
            throw err;
        }
    }
}

// Mimic the main 'pool' object
const pool = {
    connected: true,
    request: () => new FakeMssqlRequest(db),
    close: () => db.close()
};

module.exports = {
    // Mimic the sql.connect() function
    connect: async () => {
        console.log("Connected to SQLite (via Wrapper)");
        return pool;
    },
    // Export types to prevent "sql.Int is undefined" errors
    Int: 'Int',
    NVarChar: 'NVarChar',
    Bit: 'Bit',
    DateTime: 'DateTime'
};