1 files changed, 186 insertions, 0 deletions
diff --git a/src/config.c b/src/config.c
new file mode 100644
index 0000000..d676a41
--- /dev/null
+++ b/src/config.c
@@ -0,0 +1,186 @@
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <string.h>
+
+#include "any_log.h"
+#include "config.h"
+
+#define ANY_INI_IMPLEMENT
+#include "any_ini.h"
+
+typedef enum {
+    CONFIG_STRING,
+    CONFIG_INT_ANY,
+    CONFIG_INT_POSITIVE,
+    CONFIG_DOUBLE,
+} config_type_t;
+
+typedef struct {
+    const char *key;
+    config_type_t type;
+    size_t offset;
+} config_entry_t;
+
+static const config_entry_t config_entries[] = {
+    { "width",   CONFIG_INT_POSITIVE, offsetof(config_t, width) },
+    { "height",  CONFIG_INT_POSITIVE, offsetof(config_t, height) },
+    { "font",    CONFIG_STRING,       offsetof(config_t, font) },
+    { "monitor", CONFIG_STRING,       offsetof(config_t, monitor) },
+};
+
+static bool config_read_string(const char *value, char **result)
+{
+    if (value == NULL)
+        value = "";
+
+    size_t start = 0, end = strlen(value);
+    if (value[0] == '"' && value[end - 1] == '"') {
+        start++;
+        end--;
+    }
+
+    *result = malloc(end - start + 1);
+    memcpy(*result, value + start, end - start);
+    *result[end - start] = '\0';
+    return true;
+}
+
+static bool config_read_int(const char *value, int *result)
+{
+    char *end;
+    long n = strtol(value, &end, 0);
+    *result = n;
+
+    if (n > INT_MAX || n < INT_MIN)
+        log_debug("Integer is too big");
+
+    return *end == '\0' && n != LONG_MIN && n != LONG_MAX;
+}
+
+static bool config_read_double(const char *value, double *result)
+{
+    char *end;
+    *result = strtod(value, &end);
+    return *end == '\0';
+}
+
+static bool config_entry(config_t *config, int line, const char *section, const char *key, const char *value)
+{
+    const int n_entries = sizeof(config_entries) / sizeof(config_entry_t);
+
+    const char *types[] = {
+        "string",
+        "integer",
+        "positive integer",
+        "double float",
+    };
+
+    for (int i = 0; i < n_entries; i++) {
+        if (!strcmp(key, config_entries[i].key)) {
+            bool nullable = config_entries[i].type == CONFIG_STRING;
+
+            if ((value == NULL || *value == '\0') && !nullable) {
+                log_value_error("Empty config entry",
+                                "s:section", section,
+                                "s:key", key,
+                                "s:expected_type", types[config_entries[i].type],
+                                "i:line", line);
+                return false;
+            }
+
+            void *result = (uint8_t *)config + config_entries[i].offset;
+            switch (config_entries[i].type) {
+                case CONFIG_STRING:
+                    if (config_read_string(value, (char **)result))
+                        return true;
+                    break;
+
+                case CONFIG_INT_ANY:
+                    if (config_read_int(value, (int *)result))
+                        return true;
+                    break;
+
+                case CONFIG_INT_POSITIVE:
+                    if (config_read_int(value, (int *)result) && *(int *)result >= 0)
+                        return true;
+                    break;
+
+                case CONFIG_DOUBLE:
+                    if (config_read_double(value, (double *)result))
+                        return true;
+                    break;
+
+                default:
+                    log_panic("Unreachable");
+            }
+
+            log_value_error("Invalid config entry",
+                            "s:section", section,
+                            "s:key", key,
+                            "s:value", value,
+                            "s:expected_type", types[config_entries[i].type],
+                            "i:line", line);
+
+            return false;
+        }
+    }
+
+    log_value_warn("Unknown config entry",
+                   "s:section", section,
+                   "s:key", key,
+                   "s:value", value,
+                   "i:line", line);
+
+    return true;
+}
+
+static const config_t config_default = {
+    .font = "monospace 10",
+    .monitor = NULL,
+    .height = 50,
+    .width = 100,
+};
+
+void config_init(config_t *config, FILE *file)
+{
+    memcpy(config, &config_default, sizeof(config_t));
+    log_debug("Copied default config");
+
+    any_ini_stream_t ini;
+    any_ini_file_init(&ini, file);
+
+    int errors = 0;
+    char *section = NULL;
+
+    do {
+        bool unknown_section = section != NULL && strcmp(section, "bar");
+
+        if (unknown_section)
+            log_warn("Unknown section '%s'", section);
+
+        char *key;
+        while ((key = any_ini_stream_next_key(&ini)) != NULL) {
+            int line = ini.line;
+            char *value = any_ini_stream_next_value(&ini);
+
+            log_value_trace("Reading config entry",
+                            "s:section", section,
+                            "s:key", key,
+                            "s:value", value,
+                            "i:line", ini.line);
+
+            if (!unknown_section)
+                errors += !config_entry(config, ini.line, section, key, value);
+
+            free(key);
+            free(value);
+        }
+
+        free(section);
+    } while ((section = any_ini_stream_next_section(&ini)) != NULL);
+
+    if (errors > 0)
+        log_panic("Config file contained %d errors", errors);
+}