From bf91212c3e8086c580069c748208601de4303681 Mon Sep 17 00:00:00 2001
From: tommy <coder@tommywatson.com>
Date: Thu, 19 Oct 2023 16:40:33 -0400
Subject: [PATCH] Save "Best Difficulty" scores into NVS #20

---
 main/nvs_config.c | 40 ++++++++++++++++++++++++++++++++++++++++
 main/nvs_config.h |  3 +++
 main/system.c     | 12 +++++++++---
 3 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/main/nvs_config.c b/main/nvs_config.c
index 6b2816ea6..b86b5e544 100644
--- a/main/nvs_config.c
+++ b/main/nvs_config.c
@@ -96,3 +96,43 @@ void nvs_config_set_u16(const char * key, const uint16_t value)
     nvs_close(handle);
     return;
 }
+
+uint64_t nvs_config_get_u64(const char * key, const uint64_t default_value)
+{
+    nvs_handle handle;
+    esp_err_t err;
+    err = nvs_open(NVS_CONFIG_NAMESPACE, NVS_READONLY, &handle);
+    if (err != ESP_OK) {
+        return default_value;
+    }
+
+    uint64_t out;
+    err = nvs_get_u64(handle, key, &out);
+
+    if (err != ESP_OK) {
+        return default_value;
+    }
+
+    nvs_close(handle);
+    return out;
+}
+
+void nvs_config_set_u64(const char * key, const uint64_t value)
+{
+
+    nvs_handle handle;
+    esp_err_t err;
+    err = nvs_open(NVS_CONFIG_NAMESPACE, NVS_READWRITE, &handle);
+    if (err != ESP_OK) {
+        ESP_LOGW(TAG, "Could not open nvs");
+        return;
+    }
+
+    err = nvs_set_u64(handle, key, value);
+    if (err != ESP_OK) {
+        ESP_LOGW(TAG, "Could not write nvs key: %s, value: %llu", key, value);
+        return;
+    }
+    nvs_close(handle);
+    return;
+}
diff --git a/main/nvs_config.h b/main/nvs_config.h
index 9d43fc0d2..90a088581 100644
--- a/main/nvs_config.h
+++ b/main/nvs_config.h
@@ -16,10 +16,13 @@
 #define NVS_CONFIG_BOARD_VERSION "boardversion"
 #define NVS_CONFIG_FLIP_SCREEN "flipscreen"
 #define NVS_CONFIG_INVERT_SCREEN "invertscreen"
+#define NVS_CONFIG_BEST_DIFF "bestdiff"
 
 char * nvs_config_get_string(const char * key, const char * default_value);
 void nvs_config_set_string(const char * key, const char * default_value);
 uint16_t nvs_config_get_u16(const char * key, const uint16_t default_value);
 void nvs_config_set_u16(const char * key, const uint16_t value);
+uint64_t nvs_config_get_u64(const char * key, const uint64_t default_value);
+void nvs_config_set_u64(const char * key, const uint64_t value);
 
 #endif // MAIN_NVS_CONFIG_H
diff --git a/main/system.c b/main/system.c
index b65fbdbf9..e4ac987e6 100644
--- a/main/system.c
+++ b/main/system.c
@@ -43,14 +43,14 @@ static void _init_system(GlobalState * global_state, SystemModule * module)
     module->screen_page = 0;
     module->shares_accepted = 0;
     module->shares_rejected = 0;
-    module->best_nonce_diff = 0;
+    module->best_nonce_diff = nvs_config_get_u64(NVS_CONFIG_BEST_DIFF, 0);
     module->start_time = esp_timer_get_time();
     module->lastClockSync = 0;
     module->FOUND_BLOCK = false;
     module->startup_done = false;
 
-    // set the best diff string to 0
-    _suffix_string(0, module->best_diff_string, DIFF_STRING_SIZE, 0);
+    // set the best diff string
+    _suffix_string(module->best_nonce_diff, module->best_diff_string, DIFF_STRING_SIZE, 0);
 
     // set the ssid string to blank
     memset(module->ssid, 0, 20);
@@ -275,7 +275,13 @@ static void _check_for_best_diff(SystemModule * module, double diff, uint32_t nb
     if (diff < module->best_nonce_diff) {
         return;
     }
+
+    uint64_t old = module->best_nonce_diff;
     module->best_nonce_diff = diff;
+    // only write to flash if new > old
+    if(module->best_nonce_diff > old) {
+        nvs_config_set_u64(NVS_CONFIG_BEST_DIFF, module->best_nonce_diff);
+    }
     // make the best_nonce_diff into a string
     _suffix_string((uint64_t) diff, module->best_diff_string, DIFF_STRING_SIZE, 0);
     double network_diff = _calculate_network_difficulty(nbits);