Add bonus write to json

Author: savalet

include/dataframe.h

@@ -76,4 +76,5 @@ dataframe_t *df_apply(dataframe_t *df, const char *column,
     void *(*apply_func)(void *vl));
 dataframe_t *df_to_type(dataframe_t *df, char const *column,
     column_type_t downcast);
+int df_write_json(dataframe_t *df, char const *path);
 #endif /* !DATAFRAME_H_ */

src/df_write_json.c

@@ -0,0 +1,70 @@
+/*
+** EPITECH PROJECT, 2025
+** __
+** File description:
+** _
+*/
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "dataframe.h"
+
+static
+void write_value(void *vl, FILE *file, column_type_t type, char *col_name)
+{
+    fprintf(file, "    \"%s\": ", col_name);
+    switch (type) {
+        case INT:
+            fprintf(file, "%d", *(int *)vl);
+            break;
+        case UINT:
+            fprintf(file, "%u", *(uint32_t *)vl);
+            break;
+        case FLOAT:
+            fprintf(file, "%.2f", *(float *)vl);
+            break;
+        case BOOL:
+        case STRING:
+            fprintf(file, "\"%s\"", (char *)vl);
+            break;
+        default:
+            return;
+    }
+}
+
+static
+void write_values(dataframe_t *df, FILE *file)
+{
+    fprintf(file, "[\n");
+    for (int row = 0; row < df->nb_rows; row++) {
+        fprintf(file, "  {\n");
+        for (int col = 0; col < df->nb_columns; col++) {
+            write_value(df->data[row][col], file, df->column_type[col],
+                df->column_names[col]);
+            fprintf(file, "%s", col < df->nb_columns - 1 ? ",\n" : "\n");
+        }
+        fprintf(file, "  }%s", row < df->nb_rows - 1 ? ",\n" : "\n");
+    }
+    fprintf(file, "]\n");
+}
+
+int df_write_json(dataframe_t *df, char const *path)
+{
+    int fd;
+    FILE *file;
+
+    if (df == NULL || !df->nb_rows || !df->nb_columns)
+        return -1;
+    fd = open(path, O_CREAT | O_WRONLY, 0644);
+    if (!fd)
+        return -1;
+    file = fdopen(fd, "w");
+    if (file == NULL)
+        return (close(fd), -1);
+    write_values(df, file);
+    fclose(file);
+    close(fd);
+    return 0;
+}

tests/main.c

@@ -66,6 +66,7 @@ int main(int ac, char **av)
     if (df == NULL)
         return 84;
     df_write_csv(df, "result.csv");
+    df_write_json(df, "result.json");
     printf("nb_columns= %d\n", df->nb_columns);
     printf("nb_rows= %d\n", df->nb_rows);
     df_info(df);