/*
 * test_parser_cmp.prg — Compare AST output: TSqlParser vs TSqlParser2 (Pratt)
 *
 * Runs identical SQL through both parsers and verifies the AST hashes
 * are structurally identical.
 *
 * Copyright (c) 2025-2026 Charles KWON (Charles KWON OhJun)
 * All rights reserved.
 */

#include "FiveSqlDef.ch"
#include "hbclass.ch"

STATIC s_nPass := 0
STATIC s_nFail := 0

PROCEDURE Main()

   ? "================================================================"
   ? "  TSqlParser vs TSqlParser2 (Pratt) — AST Comparison"
   ? "================================================================"
   ?

   Cmp( "Simple SELECT",        "SELECT name, salary FROM employees WHERE salary > 5000" )
   Cmp( "SELECT *",             "SELECT * FROM employees" )
   Cmp( "JOIN",                 "SELECT e.name, o.product FROM employees e JOIN orders o ON e.id = o.emp_id" )
   Cmp( "LEFT JOIN",            "SELECT e.name, o.product FROM employees e LEFT JOIN orders o ON e.id = o.emp_id" )
   Cmp( "GROUP BY",             "SELECT dept, COUNT(*) AS cnt FROM employees GROUP BY dept" )
   Cmp( "HAVING",               "SELECT dept, AVG(salary) AS avg_sal FROM employees GROUP BY dept HAVING AVG(salary) > 6000" )
   Cmp( "ORDER BY DESC",        "SELECT name, salary FROM employees ORDER BY salary DESC, name ASC" )
   Cmp( "DISTINCT + TOP",       "SELECT DISTINCT TOP 5 dept FROM employees" )
   Cmp( "Subquery IN",          "SELECT name FROM employees WHERE id IN (SELECT emp_id FROM orders)" )
   Cmp( "Subquery NOT IN",      "SELECT name FROM employees WHERE id NOT IN (1, 2, 3)" )
   Cmp( "BETWEEN",              "SELECT name FROM employees WHERE salary BETWEEN 5000 AND 8000" )
   Cmp( "NOT BETWEEN",          "SELECT name FROM employees WHERE salary NOT BETWEEN 1000 AND 2000" )
   Cmp( "LIKE ESCAPE",          "SELECT name FROM products WHERE name LIKE '%10!%%' ESCAPE '!'" )
   Cmp( "IS NULL",              "SELECT name FROM employees WHERE mgr_id IS NULL" )
   Cmp( "IS NOT NULL",          "SELECT name FROM employees WHERE mgr_id IS NOT NULL" )
   Cmp( "OR + AND",             "SELECT * FROM employees WHERE dept = 'Sales' OR (salary > 7000 AND mgr_id = 0)" )
   Cmp( "NOT",                  "SELECT * FROM employees WHERE NOT (salary < 5000)" )
   Cmp( "Arithmetic",           "SELECT name, salary * 12 + 1000 AS annual FROM employees" )
   Cmp( "Unary minus",          "SELECT -salary FROM employees" )
   Cmp( "String concat",        "SELECT name || ' - ' || dept FROM employees" )
   Cmp( "CASE WHEN",            "SELECT name, CASE WHEN salary > 7000 THEN 'High' WHEN salary > 5000 THEN 'Mid' ELSE 'Low' END AS tier FROM employees" )
   Cmp( "Nested function",      "SELECT UPPER(SUBSTR(name, 1, 3)) FROM employees" )
   Cmp( "COUNT(*)",             "SELECT COUNT(*) FROM employees" )
   Cmp( "Window ROW_NUMBER",    "SELECT name, ROW_NUMBER() OVER (ORDER BY salary DESC) AS rn FROM employees" )
   Cmp( "Window PARTITION",     "SELECT name, RANK() OVER (PARTITION BY dept ORDER BY salary DESC) AS rnk FROM employees" )
   Cmp( "UNION ALL",            "SELECT name FROM employees WHERE dept = 'Sales' UNION ALL SELECT name FROM employees WHERE dept = 'HR'" )
   Cmp( "INSERT",               "INSERT INTO employees (id, name) VALUES (99, 'Test')" )
   Cmp( "UPDATE",               "UPDATE employees SET salary = 9999 WHERE id = 1" )
   Cmp( "DELETE",               "DELETE FROM employees WHERE id = 99" )
   Cmp( "CTE simple",           "WITH top_e AS (SELECT name FROM employees WHERE salary > 7000) SELECT * FROM top_e" )

   ?
   ? "================================================================"
   ? "  Pass: " + hb_ntos( s_nPass ) + "/" + hb_ntos( s_nPass + s_nFail )
   IF s_nFail == 0
      ? "  ALL AST OUTPUTS IDENTICAL"
   ENDIF
   ? "================================================================"

RETURN


STATIC FUNCTION Cmp( cLabel, cSQL )

   LOCAL oLex, aTokens, oP1, oP2, h1, h2
   LOCAL cAST1, cAST2

   /* Tokenize once */
   oLex := TSqlLexer():New( cSQL )
   oLex:Tokenize()
   aTokens := oLex:GetTokens()

   /* Parse with TSqlParser (original) */
   oP1 := TSqlParser():New( AClone( aTokens ), {} )
   h1 := oP1:Parse()

   /* Parse with TSqlParser2 (Pratt) */
   oP2 := TSqlParser2():New( AClone( aTokens ), {} )
   h2 := oP2:Parse()

   /* Serialize both ASTs for comparison */
   cAST1 := hb_ValToExp( h1 )
   cAST2 := hb_ValToExp( h2 )

   IF cAST1 == cAST2
      s_nPass++
      ? "  PASS: " + cLabel
   ELSE
      s_nFail++
      ? "  FAIL: " + cLabel
      ? "    P1: " + Left( cAST1, 120 )
      ? "    P2: " + Left( cAST2, 120 )
   ENDIF

RETURN NIL