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

/* Wrapper for the static function under test (provided by the module). */
extern int test_renameEditSql(
  sqlite3_context *pCtx,
  RenameCtx *pRename,
  const char *zSql,
  const char *zNew,
  int bQuote
);

/* Helper: add a RenameToken covering the span [start, start+n) within zSql. */
static void addTokenSpan(sqlite3 *db, RenameCtx *p, const char *zSql, int start, int n){
  RenameToken *pTok = (RenameToken*)sqlite3DbMallocZero(db, sizeof(RenameToken));
  TEST_ASSERT_NOT_NULL_MESSAGE(pTok, "Failed to allocate RenameToken");
  pTok->t.z = zSql + start;
  pTok->t.n = n;
  pTok->pNext = p->pList;
  p->pList = pTok;
  p->nList++;
}

/* Helper: find and add token for the first occurrence of substring sub in zSql. */
static void addTokenForSubstring(sqlite3 *db, RenameCtx *p, const char *zSql, const char *sub){
  const char *pos = strstr(zSql, sub);
  TEST_ASSERT_NOT_NULL_MESSAGE(pos, "Substring not found in SQL");
  int start = (int)(pos - zSql);
  addTokenSpan(db, p, zSql, start, (int)strlen(sub));
}

/* Helper: initialize a sqlite3_context that can be used by renameEditSql */
static void initContext(sqlite3_context *pCtx, sqlite3 *db, Vdbe *pVdbe){
  memset(pCtx, 0, sizeof(*pCtx));
  memset(pVdbe, 0, sizeof(*pVdbe));
  pVdbe->db = db;
  pCtx->pVdbe = pVdbe;
  sqlite3VdbeMemInit(&pCtx->s, db, 0);
}

/* Helper: call test_renameEditSql and fetch result string from context. 
   Returns rc and sets *pzOut to point to the Mem string (owned by pCtx->s). */
static int call_and_result(sqlite3 *db, RenameCtx *pRename, const char *zSql,
                           const char *zNew, int bQuote, char const **pzOut){
  sqlite3_context ctx;
  Vdbe vdbe;
  initContext(&ctx, db, &vdbe);

  int rc = test_renameEditSql(&ctx, pRename, zSql, zNew, bQuote);
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, rc);
  TEST_ASSERT_NOT_NULL_MESSAGE(ctx.s.z, "No result text produced");
  *pzOut = (const char*)ctx.s.z;

  /* We intentionally do not release ctx.s here to allow caller to inspect it.
     Caller must call sqlite3VdbeMemRelease on a copy of the Mem. */
  /* Make a shallow copy of Mem to release after check */
  Mem sCopy = ctx.s;
  /* Zero original to avoid double-free after release of sCopy */
  memset(&ctx.s, 0, sizeof(ctx.s));
  sqlite3VdbeMemRelease(&sCopy);
  return rc;
}

void setUp(void) {
  /* Setup code here, or leave empty */
}
void tearDown(void) {
  /* Cleanup code here, or leave empty */
}

/* Test 1: Basic unquoted replacement with multiple tokens. */
void test_renameEditSql_basic_unquoted_multiple(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  const char *zSql = "CREATE TABLE t (old, b, old);";
  RenameCtx ctxRename;
  memset(&ctxRename, 0, sizeof(ctxRename));

  /* Add both occurrences of "old" as tokens (add in reverse order to
     test that order of pList is not required to be sorted). */
  const char *first = strstr(zSql, "old");
  const char *second = strstr(first+1, "old");
  TEST_ASSERT_NOT_NULL(first);
  TEST_ASSERT_NOT_NULL(second);
  addTokenSpan(db, &ctxRename, zSql, (int)(second - zSql), 3);
  addTokenSpan(db, &ctxRename, zSql, (int)(first - zSql), 3);

  const char *zNew = "newname";
  const char *zOut = NULL;
  call_and_result(db, &ctxRename, zSql, zNew, 0, &zOut);

  TEST_ASSERT_EQUAL_STRING("CREATE TABLE t (newname, b, newname);", zOut);
  /* The function should have consumed all tokens */
  TEST_ASSERT_NULL(ctxRename.pList);

  sqlite3_close(db);
}

/* Test 2: Force quoting with bQuote==1. */
void test_renameEditSql_force_quote_bQuote1(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  const char *zSql = "CREATE TABLE t (old);";
  RenameCtx ctxRename;
  memset(&ctxRename, 0, sizeof(ctxRename));

  addTokenForSubstring(db, &ctxRename, zSql, "old");

  const char *zNew = "col name"; /* requires quoting */
  const char *zOut = NULL;
  call_and_result(db, &ctxRename, zSql, zNew, 1, &zOut);

  TEST_ASSERT_EQUAL_STRING("CREATE TABLE t (\"col name\");", zOut);
  TEST_ASSERT_NULL(ctxRename.pList);

  sqlite3_close(db);
}

/* Test 3: Original token is quoted, bQuote==0 still results in quoted replacement. */
void test_renameEditSql_quoted_input_bQuote0(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  const char *zSql = "SELECT \"old\" FROM t;";
  RenameCtx ctxRename;
  memset(&ctxRename, 0, sizeof(ctxRename));

  addTokenForSubstring(db, &ctxRename, zSql, "\"old\"");

  const char *zNew = "foo";
  const char *zOut = NULL;
  call_and_result(db, &ctxRename, zSql, zNew, 0, &zOut);

  TEST_ASSERT_EQUAL_STRING("SELECT \"foo\" FROM t;", zOut);
  TEST_ASSERT_NULL(ctxRename.pList);

  sqlite3_close(db);
}

/* Test 4: zNew==NULL converts double-quoted token to single-quoted text and
   inserts a space if immediately followed by a single-quote. */
void test_renameEditSql_null_zNew_single_quote_conversion_with_space(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  /* Case with following single-quote -> space should be inserted */
  {
    const char *zSql = "SELECT \"string\"'alias'";
    RenameCtx ctxRename;
    memset(&ctxRename, 0, sizeof(ctxRename));
    addTokenForSubstring(db, &ctxRename, zSql, "\"string\"");
    const char *zOut = NULL;
    call_and_result(db, &ctxRename, zSql, NULL, 0, &zOut);
    TEST_ASSERT_EQUAL_STRING("SELECT 'string' 'alias'", zOut);
    TEST_ASSERT_NULL(ctxRename.pList);
  }

  /* Case without following single-quote -> no extra space */
  {
    const char *zSql = "SELECT \"data\";";
    RenameCtx ctxRename;
    memset(&ctxRename, 0, sizeof(ctxRename));
    addTokenForSubstring(db, &ctxRename, zSql, "\"data\"");
    const char *zOut = NULL;
    call_and_result(db, &ctxRename, zSql, NULL, 0, &zOut);
    TEST_ASSERT_EQUAL_STRING("SELECT 'data';", zOut);
    TEST_ASSERT_NULL(ctxRename.pList);
  }

  sqlite3_close(db);
}

/* Test 5: No tokens -> SQL should be returned unchanged (zNew non-NULL). */
void test_renameEditSql_no_tokens_sql_unchanged(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  const char *zSql = "CREATE VIEW v AS SELECT a, b FROM t;";
  RenameCtx ctxRename;
  memset(&ctxRename, 0, sizeof(ctxRename));

  const char *zOut = NULL;
  call_and_result(db, &ctxRename, zSql, "x", 0, &zOut);
  TEST_ASSERT_EQUAL_STRING(zSql, zOut);
  TEST_ASSERT_NULL(ctxRename.pList);

  sqlite3_close(db);
}

/* Test 6: Multiple tokens out-of-order in pList, ensure all replaced correctly. */
void test_renameEditSql_multiple_tokens_out_of_order(void){
  sqlite3 *db = 0;
  TEST_ASSERT_EQUAL_INT(SQLITE_OK, sqlite3_open(":memory:", &db));

  const char *zSql = "UPDATE t SET old = 1, x = old, y = old;";
  RenameCtx ctxRename;
  memset(&ctxRename, 0, sizeof(ctxRename));

  /* Find three occurrences of "old" and add them in jumbled order */
  const char *p = zSql;
  int offs[3];
  for(int i=0;i<3;i++){
    p = strstr(p, "old");
    TEST_ASSERT_NOT_NULL(p);
    offs[i] = (int)(p - zSql);
    p += 3;
  }
  /* Add in order 2,0,1 */
  addTokenSpan(db, &ctxRename, zSql, offs[2], 3);
  addTokenSpan(db, &ctxRename, zSql, offs[0], 3);
  addTokenSpan(db, &ctxRename, zSql, offs[1], 3);

  const char *zOut = NULL;
  call_and_result(db, &ctxRename, zSql, "nn", 0, &zOut);

  TEST_ASSERT_EQUAL_STRING("UPDATE t SET nn = 1, x = nn, y = nn;", zOut);
  TEST_ASSERT_NULL(ctxRename.pList);

  sqlite3_close(db);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_renameEditSql_basic_unquoted_multiple);
  RUN_TEST(test_renameEditSql_force_quote_bQuote1);
  RUN_TEST(test_renameEditSql_quoted_input_bQuote0);
  RUN_TEST(test_renameEditSql_null_zNew_single_quote_conversion_with_space);
  RUN_TEST(test_renameEditSql_no_tokens_sql_unchanged);
  RUN_TEST(test_renameEditSql_multiple_tokens_out_of_order);
  return UNITY_END();
}