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

/* Globals for test */
static sqlite3 *gDb = NULL;
static Parse gParse;

/* Helper: add a RenameToken to gParse.pRename pointing at p */
static RenameToken* addRenameToken(void *p){
  RenameToken *r = (RenameToken*)sqlite3_malloc(sizeof(RenameToken));
  TEST_ASSERT_NOT_NULL(r);
  memset(r, 0, sizeof(*r));
  r->p = p;
  r->pNext = gParse.pRename;
  gParse.pRename = r;
  return r;
}

/* Helper: free all RenameToken nodes in gParse.pRename */
static void freeAllRenameTokens(void){
  RenameToken *p = gParse.pRename;
  while( p ){
    RenameToken *pNext = p->pNext;
    sqlite3_free(p);
    p = pNext;
  }
  gParse.pRename = NULL;
}

void setUp(void) {
  int rc = sqlite3_open(":memory:", &gDb);
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, rc);
  memset(&gParse, 0, sizeof(gParse));
  gParse.db = gDb;
  gParse.pRename = NULL;
}

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

/* Utility: create an ExprList with a single integer expression and assign alias */
static ExprList* makeExprListWithAlias(Parse *pParse, int val, const char *alias){
  char buf[32];
  sqlite3_snprintf(sizeof(buf), buf, "%d", val);
  Expr *pExpr = sqlite3Expr(pParse->db, TK_INTEGER, buf);
  TEST_ASSERT_NOT_NULL(pExpr);
  ExprList *pList = sqlite3ExprListAppend(pParse, NULL, pExpr);
  TEST_ASSERT_NOT_NULL(pList);
  Token t;
  t.z = (char*)alias;
  t.n = (int)strlen(alias);
  sqlite3ExprListSetName(pParse, pList, &t, 1);
  return pList;
}

/* Utility: append another integer expression with alias to an existing list */
static void appendExprWithAlias(Parse *pParse, ExprList **ppList, int val, const char *alias){
  char buf[32];
  sqlite3_snprintf(sizeof(buf), buf, "%d", val);
  Expr *pExpr = sqlite3Expr(pParse->db, TK_INTEGER, buf);
  TEST_ASSERT_NOT_NULL(pExpr);
  *ppList = sqlite3ExprListAppend(pParse, *ppList, pExpr);
  TEST_ASSERT_NOT_NULL(*ppList);
  Token t;
  t.z = (char*)alias;
  t.n = (int)strlen(alias);
  sqlite3ExprListSetName(pParse, *ppList, &t, 1);
}

/* Test: passing NULL pEList is a no-op (tokens unchanged) */
void test_sqlite3RenameExprlistUnmap_null_list_noop(void){
  int dummy1 = 0x11;
  int dummy2 = 0x22;
  RenameToken *rt1 = addRenameToken(&dummy1);
  RenameToken *rt2 = addRenameToken(&dummy2);

  sqlite3RenameExprlistUnmap(&gParse, NULL);

  TEST_ASSERT_EQUAL_PTR(&dummy1, rt1->p);
  TEST_ASSERT_EQUAL_PTR(&dummy2, rt2->p);
}

/* Test: unmaps tokens for expression nodes and zEName aliases in the list */
void test_sqlite3RenameExprlistUnmap_unmaps_expr_nodes_and_aliases(void){
  /* Build ExprList with two items: 1 AS a, 2 AS b */
  ExprList *pList = makeExprListWithAlias(&gParse, 1, "a");
  appendExprWithAlias(&gParse, &pList, 2, "b");

  /* Capture pointers to alias names and one expression node */
  TEST_ASSERT_TRUE(pList->nExpr >= 2);
  char *zName0 = pList->a[0].zEName;
  char *zName1 = pList->a[1].zEName;
  TEST_ASSERT_NOT_NULL(zName0);
  TEST_ASSERT_NOT_NULL(zName1);
  Expr *pExpr0 = pList->a[0].pExpr;
  TEST_ASSERT_NOT_NULL(pExpr0);

  /* Create RenameToken entries for:
  **  - The first expression node pointer (should be unmapped by walker)
  **  - Both alias zEName pointers (should be unmapped by explicit remap)
  **  - An unrelated pointer (should remain unchanged)
  */
  int unrelatedDummy = 0xABCD;
  RenameToken *rtExpr = addRenameToken((void*)pExpr0);
  RenameToken *rtName0 = addRenameToken((void*)zName0);
  RenameToken *rtName1 = addRenameToken((void*)zName1);
  RenameToken *rtUnrelated = addRenameToken(&unrelatedDummy);

  /* Call function under test */
  sqlite3RenameExprlistUnmap(&gParse, pList);

  /* Validate: mapped tokens for expr and names are cleared; unrelated unchanged */
  TEST_ASSERT_NULL(rtExpr->p);
  TEST_ASSERT_NULL(rtName0->p);
  TEST_ASSERT_NULL(rtName1->p);
  TEST_ASSERT_EQUAL_PTR(&unrelatedDummy, rtUnrelated->p);

  sqlite3ExprListDelete(gDb, pList);
}

/* Test: when there are no matching tokens (neither expr nodes nor zEName),
** the rename list remains unchanged. */
void test_sqlite3RenameExprlistUnmap_no_matching_tokens(void){
  ExprList *pList = makeExprListWithAlias(&gParse, 3, "c");
  /* Create a token that does not correspond to any node or alias in pList */
  int other = 123;
  RenameToken *rtOther = addRenameToken(&other);

  /* Sanity: ensure we did NOT add tokens pointing to pList's nodes or zEName */
  TEST_ASSERT_NOT_NULL(pList->a[0].pExpr);
  TEST_ASSERT_NOT_NULL(pList->a[0].zEName);
  TEST_ASSERT_NOT_EQUAL_PTR(pList->a[0].pExpr, rtOther->p);
  TEST_ASSERT_NOT_EQUAL_PTR(pList->a[0].zEName, rtOther->p);

  sqlite3RenameExprlistUnmap(&gParse, pList);

  /* No changes expected */
  TEST_ASSERT_EQUAL_PTR(&other, rtOther->p);

  sqlite3ExprListDelete(gDb, pList);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_sqlite3RenameExprlistUnmap_null_list_noop);
  RUN_TEST(test_sqlite3RenameExprlistUnmap_unmaps_expr_nodes_and_aliases);
  RUN_TEST(test_sqlite3RenameExprlistUnmap_no_matching_tokens);
  return UNITY_END();
}