1 files changed, 124 insertions, 0 deletions
diff --git a/db.c b/db.c
new file mode 100644
index 0000000..ff9388c
--- /dev/null
+++ b/db.c
@@ -0,0 +1,124 @@
+//
+// Created by yuuta on 11/28/21.
+//
+
+#include "db.h"
+#include "log.h"
+#include "botd.h"
+
+#include <stdio.h>
+#include <sqlite3.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdbool.h>
+
+#ifndef SQL_PATH
+#define SQL_PATH "../sql/"
+#endif
+
+sqlite3 *db = NULL;
+
+void db_init(void) {
+    int r;
+    r = sqlite3_open(cmd.db_path, &db);
+    if (r) {
+        LOGFEV("Cannot open SQLite3 database: %s", r, sqlite3_errstr(r));
+    }
+    char *errmsg = NULL;
+    /* Enable foreign key support */
+    r = sqlite3_exec(db, "PRAGMA foreign_keys = ON;", NULL, NULL, &errmsg);
+    if (r) {
+        goto sql_err;
+        sql_err:
+        db_close();
+        LOGFEV("%s", r, errmsg);
+    }
+    /* Get user_version */
+    sqlite3_stmt *stmt;
+    r = sqlite3_prepare_v2(db, "PRAGMA user_version", -1, &stmt, 0);
+    if (r) {
+        goto sql_err;
+    }
+    r = sqlite3_step(stmt);
+    if (r != SQLITE_ROW) {
+        sqlite3_finalize(stmt);
+        goto sql_err;
+    }
+    const int current_var = sqlite3_column_int(stmt, 0);
+    r = sqlite3_finalize(stmt);
+    /* Upgrade one by one */
+    FILE *fd_sql = NULL;
+    char *path_sql = NULL;
+    const unsigned int path_len = strlen(SQL_PATH) + 20;
+    path_sql = calloc(path_len, sizeof(char));
+    if (path_sql == NULL) {
+        r = errno;
+        db_close();
+        LOGFEV("Cannot allocate memory: %s", r, strerror(r));
+    }
+    for (int i = current_var; true; i++) {
+        snprintf(path_sql, path_len - 1, "%s/%d_%d.sql", SQL_PATH, i, i + 1);
+        fd_sql = fopen(path_sql, "r");
+        if (fd_sql == NULL) {
+            if (errno != ENOENT) {
+                r = errno;
+                free(path_sql);
+                db_close();
+                LOGFEV("Cannot upgrade database to %d: %s", r, i + 1, strerror(r));
+            }
+            break;
+        }
+        char *sql_str = NULL;
+        char *line = NULL;
+        size_t len = 0;
+        ssize_t tread = 0;
+        ssize_t nread;
+        while ((nread = getline(&line, &len, fd_sql)) != -1) {
+            tread += nread;
+            if (sql_str == NULL) {
+                sql_str = calloc(nread + 1, sizeof(char));
+                if (sql_str == NULL) {
+                    r = errno;
+                    fclose(fd_sql);
+                    free(line);
+                    free(path_sql);
+                    db_close();
+                    LOGFEV("Cannot allocate memory: %s", r, strerror(r));
+                }
+                strcpy(sql_str, line);
+            } else {
+                char *newptr = realloc(sql_str, (tread + 1) * sizeof(char));
+                if (newptr == NULL) {
+                    r = errno;
+                    fclose(fd_sql);
+                    free(line);
+                    free(sql_str);
+                    free(path_sql);
+                    db_close();
+                    LOGFEV("Cannot allocate memory: %s", r, strerror(r));
+                }
+                sql_str = newptr;
+                strcat(sql_str, line);
+            }
+        }
+        fclose(fd_sql);
+        free(line);
+        r = sqlite3_exec(db, sql_str, NULL, NULL, &errmsg);
+        if (r) {
+            free(sql_str);
+            db_close();
+            LOGFV("%s", errmsg);
+            break;
+        }
+        free(sql_str);
+    }
+    free(path_sql);
+}
+
+void db_close(void) {
+    if (db == NULL)
+        return;
+    sqlite3_close(db);
+    db = NULL;
+}