#include "sqliteInt.h"
#include "unity.h"
#include <stdlib.h>
#include <string.h>

/* Global test database connection */
static sqlite3 *gDb = NULL;

/* Wrapper provided by the module for testing the static function */
extern void test_renameTestSchema(
  Parse *pParse,
  const char *zDb,
  int bTemp,
  const char *zWhen,
  int bNoDQS
);

/* Provide sqlite_rename_test function so nested parses compile and run */
static void xRenameTestFunc(sqlite3_context *ctx, int argc, sqlite3_value **argv){
  /* This function is used by nested parse SQL: return NULL to satisfy "=NULL" */
  SQLITE_USE(argc);
  SQLITE_USE(argv);
  sqlite3_result_null(ctx);
}

/* Helper: initialize a fresh Parse object bound to gDb */
static void initParse(Parse *p){
  memset(p, 0, sizeof(*p));
  p->db = gDb;
}

/* Helper: cleanup VDBE and error message in Parse to avoid leaks */
static void cleanupParse(Parse *p){
  if( p->pVdbe ){
    sqlite3VdbeDelete(p->pVdbe);
    p->pVdbe = 0;
  }
  if( p->zErrMsg ){
    sqlite3DbFree(p->db, p->zErrMsg);
    p->zErrMsg = 0;
  }
}

void setUp(void) {
  int rc = sqlite3_open(":memory:", &gDb);
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, rc);

  /* Register sqlite_rename_test(name in SQL) with 6 args */
  rc = sqlite3_create_function(gDb, "sqlite_rename_test", 6,
                               SQLITE_UTF8, 0,
                               xRenameTestFunc, 0, 0);
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, rc);
}

void tearDown(void) {
  if( gDb ){
    int rc = sqlite3_close(gDb);
    TEST_ASSERT_EQUAL_INT(SQLITE_OK, rc);
    gDb = NULL;
  }
}

/* Basic sanity: sets colNamesSet, creates a VDBE, and emits some code */
void test_renameTestSchema_sets_colNamesSet_and_creates_vdbe(void){
  Parse p;
  initParse(&p);

  test_renameTestSchema(&p, "main", 0, "during rename", 0);

  /* Verify colNamesSet is set */
  TEST_ASSERT_EQUAL_INT(1, p.colNamesSet);

  /* Verify a VDBE was created and has some ops */
  TEST_ASSERT_NOT_NULL(p.pVdbe);
  int nOp = sqlite3VdbeCurrentAddr(p.pVdbe);
  TEST_ASSERT_TRUE(nOp > 0);

  cleanupParse(&p);
}

/* bTemp affects the number of nested parses: 0 => two queries, 1 => one query */
void test_renameTestSchema_bTemp_affects_instruction_count(void){
  Parse p1, p2;
  initParse(&p1);
  initParse(&p2);

  /* One nested parse (temp db only) */
  test_renameTestSchema(&p1, "temp", 1, "phase A", 0);
  TEST_ASSERT_EQUAL_INT(1, p1.colNamesSet);
  TEST_ASSERT_NOT_NULL(p1.pVdbe);
  int nOp1 = sqlite3VdbeCurrentAddr(p1.pVdbe);
  TEST_ASSERT_TRUE(nOp1 > 0);

  /* Two nested parses (main + temp) */
  test_renameTestSchema(&p2, "main", 0, "phase B", 0);
  TEST_ASSERT_EQUAL_INT(1, p2.colNamesSet);
  TEST_ASSERT_NOT_NULL(p2.pVdbe);
  int nOp2 = sqlite3VdbeCurrentAddr(p2.pVdbe);
  TEST_ASSERT_TRUE(nOp2 > 0);

  /* Expect more ops when bTemp==0 due to the extra nested SELECT */
  TEST_ASSERT_TRUE(nOp2 > nOp1);

  cleanupParse(&p1);
  cleanupParse(&p2);
}

/* Using "temp" db name with bTemp==1 should still function correctly */
void test_renameTestSchema_temp_db_only(void){
  Parse p;
  initParse(&p);

  test_renameTestSchema(&p, "temp", 1, "temp-only", 1 /* bNoDQS */);

  TEST_ASSERT_EQUAL_INT(1, p.colNamesSet);
  TEST_ASSERT_NOT_NULL(p.pVdbe);
  int nOp = sqlite3VdbeCurrentAddr(p.pVdbe);
  TEST_ASSERT_TRUE(nOp > 0);

  cleanupParse(&p);
}

/* Ensure NULL zWhen and varying bNoDQS do not crash and still generate code */
void test_renameTestSchema_null_when_and_noDQS_variations(void){
  Parse pA, pB;
  initParse(&pA);
  initParse(&pB);

  /* zWhen NULL, bNoDQS = 0 */
  test_renameTestSchema(&pA, "main", 0, NULL, 0);
  TEST_ASSERT_EQUAL_INT(1, pA.colNamesSet);
  TEST_ASSERT_NOT_NULL(pA.pVdbe);
  int nOpA = sqlite3VdbeCurrentAddr(pA.pVdbe);
  TEST_ASSERT_TRUE(nOpA > 0);

  /* zWhen NULL, bNoDQS = 1 */
  test_renameTestSchema(&pB, "main", 0, NULL, 1);
  TEST_ASSERT_EQUAL_INT(1, pB.colNamesSet);
  TEST_ASSERT_NOT_NULL(pB.pVdbe);
  int nOpB = sqlite3VdbeCurrentAddr(pB.pVdbe);
  TEST_ASSERT_TRUE(nOpB > 0);

  cleanupParse(&pA);
  cleanupParse(&pB);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_renameTestSchema_sets_colNamesSet_and_creates_vdbe);
  RUN_TEST(test_renameTestSchema_bTemp_affects_instruction_count);
  RUN_TEST(test_renameTestSchema_temp_db_only);
  RUN_TEST(test_renameTestSchema_null_when_and_noDQS_variations);
  return UNITY_END();
}