Create the sorted index of modes and palettes at startup (#1741)

* Very incomplete work toward sorting.

* Sort modes and palettes upon startup so I don't have to maintain the static index array.

* Remove cpp test file I used for development

* Added ModeSortUsermod, modified the other two usermods to use it.

* Update platformio_override.ini.sample and readme for ModeSortUsermod

* restore methods accidentally removed.

usermods/usermod_v2_mode_sort/readme.md

@@ -0,0 +1,33 @@
+# Mode Sort
+
+v2 usermod that provides data about modes and
+palettes to other usermods. Notably it provides:
+* A direct method for a mode or palette name
+* Ability to retrieve mode and palette names in 
+  alphabetical order
+
+```char **getModesQStrings()```
+
+Provides an array of char* (pointers) to the names of the
+palettes within JSON_mode_names, in the same order as 
+JSON_mode_names. These strings end in double quote (")
+(or \0 if there is a problem).
+
+```byte *getModesAlphaIndexes()```
+
+An array of byte designating the indexes of names of the
+modes in alphabetical order. "Solid" will always remain 
+at the front of the list.
+
+```char **getPalettesQStrings()```
+
+Provides an array of char* (pointers) to the names of the
+palettes within JSON_palette_names, in the same order as 
+JSON_palette_names. These strings end in double quote (")
+(or \0 if there is a problem).
+
+```byte *getPalettesAlphaIndexes()```
+
+An array of byte designating the indexes of names of the
+palettes in alphabetical order. "Default" and those
+starting with "(" will always remain at the front of the list.

usermods/usermod_v2_mode_sort/usermod_v2_mode_sort.h

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+#pragma once
+
+#include "wled.h"
+
+//
+// v2 usermod that provides data about modes and
+// palettes to other usermods. Notably it provides:
+// * A direct method for a mode or palette name
+// * Ability to retrieve mode and palette names in 
+//   alphabetical order
+// 
+// char **getModesQStrings()
+// Provides an array of char* (pointers) to the names of the
+// palettes within JSON_mode_names, in the same order as 
+// JSON_mode_names. These strings end in double quote (")
+// (or \0 if there is a problem).
+//
+// byte *getModesAlphaIndexes()
+// An array of byte designating the indexes of names of the
+// modes in alphabetical order. "Solid" will always remain 
+// at the front of the list.
+//
+// char **getPalettesQStrings()
+// Provides an array of char* (pointers) to the names of the
+// palettes within JSON_palette_names, in the same order as 
+// JSON_palette_names. These strings end in double quote (")
+// (or \0 if there is a problem).
+//
+// byte *getPalettesAlphaIndexes()
+// An array of byte designating the indexes of names of the
+// palettes in alphabetical order. "Default" and those
+// starting with "(" will always remain at the front of the list.
+//
+
+// Number of modes at the start of the list to not sort
+#define MODE_SORT_SKIP_COUNT 1
+
+// Which list is being sorted
+char **listBeingSorted = nullptr;
+
+/**
+ * Modes and palettes are stored as strings that
+ * end in a quote character. Compare two of them.
+ * We are comparing directly within either
+ * JSON_mode_names or JSON_palette_names.
+ */
+int re_qstringCmp(const void *ap, const void *bp) {
+    char *a = listBeingSorted[*((byte *)ap)];
+    char *b = listBeingSorted[*((byte *)bp)];
+    int i = 0;
+    do {
+        char aVal = pgm_read_byte_near(a + i);
+        if (aVal >= 97 && aVal <= 122) {
+            // Lowercase
+            aVal -= 32;
+        }
+        char bVal = pgm_read_byte_near(b + i);
+        if (bVal >= 97 && bVal <= 122) {
+            // Lowercase
+            bVal -= 32;
+        }
+        // Relly we shouldn't ever get to '\0'
+        if (aVal == '"' || bVal == '"' || aVal == '\0' || bVal == '\0') {
+            // We're done. one is a substring of the other
+            // or something happenend and the quote didn't stop us.
+            if (aVal == bVal) {
+                // Same value, probably shouldn't happen
+                // with this dataset
+                return 0;
+            }
+            else if (aVal == '"' || aVal == '\0') {
+                return -1;
+            }
+            else {
+                return 1;
+            }
+        }
+        if (aVal == bVal) {
+            // Same characters. Move to the next.
+            i++;
+            continue;
+        }
+        // We're done
+        if (aVal < bVal) {
+            return -1;
+        }
+        else {
+            return 1;
+        }
+    } while (true);
+    // We shouldn't get here.
+    return 0;
+}
+
+class ModeSortUsermod : public Usermod {
+private:
+
+    // Pointers the start of the mode names within JSON_mode_names
+    char **modes_qstrings = nullptr;
+
+    // Array of mode indexes in alphabetical order.
+    byte *modes_alpha_indexes = nullptr;
+
+    // Pointers the start of the palette names within JSON_palette_names
+    char **palettes_qstrings = nullptr;
+
+    // Array of palette indexes in alphabetical order.
+    byte *palettes_alpha_indexes = nullptr;
+
+public:
+    /**
+     * setup() is called once at boot. WiFi is not yet connected at this point.
+     * You can use it to initialize variables, sensors or similar.
+     */
+    void setup() {
+        // Sort the modes and palettes on startup
+        // as they are guarantted to change.
+        sortModesAndPalettes();
+    }
+
+    char **getModesQStrings() {
+        return modes_qstrings;
+    }
+
+    byte *getModesAlphaIndexes() {
+        return modes_alpha_indexes;
+    }
+
+    char **getPalettesQStrings() {
+        return palettes_qstrings;
+    }
+
+    byte *getPalettesAlphaIndexes() {
+        return palettes_alpha_indexes;
+    }
+
+    /**
+     * This Usermod doesn't have anything for loop.
+     */
+    void loop() {}
+
+    /**
+     * Sort the modes and palettes to the index arrays
+     * modes_alpha_indexes and palettes_alpha_indexes.
+     */
+    void sortModesAndPalettes() {
+        modes_qstrings = re_findModeStrings(JSON_mode_names, strip.getModeCount());
+        modes_alpha_indexes = re_initIndexArray(strip.getModeCount());
+        re_sortModes(modes_qstrings, modes_alpha_indexes, strip.getModeCount(), MODE_SORT_SKIP_COUNT);
+
+        palettes_qstrings = re_findModeStrings(JSON_palette_names, strip.getPaletteCount());
+        palettes_alpha_indexes = re_initIndexArray(strip.getPaletteCount());
+
+        int skipPaletteCount = 1;
+        while (true) {
+            // How many palette names start with '*' and should not be sorted?
+            // (Also skipping the first one, 'Default').
+            if (pgm_read_byte_near(palettes_qstrings[skipPaletteCount]) == '*') {
+                skipPaletteCount++;
+            }
+            else {
+                break;
+            }
+        }
+
+        re_sortModes(palettes_qstrings, palettes_alpha_indexes, strip.getPaletteCount(), skipPaletteCount);
+    }
+
+    byte *re_initIndexArray(int numModes) {
+        byte *indexes = (byte *)malloc(sizeof(byte) * numModes);
+        for (byte i = 0; i < numModes; i++) {
+            indexes[i] = i;
+        }
+        return indexes;
+    }
+
+    /**
+     * Return an array of mode or palette names from the JSON string.
+     * They don't end in '\0', they end in '"'. 
+     */
+    char **re_findModeStrings(const char json[], int numModes) {
+        char **modeStrings = (char **)malloc(sizeof(char *) * numModes);
+        uint8_t modeIndex = 0;
+        bool insideQuotes = false;
+        // advance past the mark for markLineNum that may exist.
+        char singleJsonSymbol;
+
+        // Find the mode name in JSON
+        bool complete = false;
+        for (size_t i = 0; i < strlen_P(json); i++) {
+            singleJsonSymbol = pgm_read_byte_near(json + i);
+            switch (singleJsonSymbol) {
+            case '"':
+                insideQuotes = !insideQuotes;
+                if (insideQuotes) {
+                    // We have a new mode or palette
+                    modeStrings[modeIndex] = (char *)(json + i + 1);
+                }
+                break;
+            case '[':
+                break;
+            case ']':
+                complete = true;
+                break;
+            case ',':
+                modeIndex++;
+            default:
+                if (!insideQuotes) {
+                    break;
+                }
+            }
+            if (complete) {
+                break;
+            }
+        }
+        return modeStrings;
+    }
+
+    /**
+   * Sort either the modes or the palettes using quicksort.
+   */
+    void re_sortModes(char **modeNames, byte *indexes, int count, int numSkip) {
+        listBeingSorted = modeNames;
+        qsort(indexes + numSkip, count - numSkip, sizeof(byte), re_qstringCmp);
+        listBeingSorted = nullptr;
+    }
+
+    /*
+     * addToJsonState() can be used to add custom entries to the /json/state part of the JSON API (state object).
+     * Values in the state object may be modified by connected clients
+     */
+    void addToJsonState(JsonObject &root) {}
+
+    /*
+     * readFromJsonState() can be used to receive data clients send to the /json/state part of the JSON API (state object).
+     * Values in the state object may be modified by connected clients
+     */
+    void readFromJsonState(JsonObject &root) {}
+
+    /*
+     * getId() allows you to optionally give your V2 usermod an unique ID (please define it in const.h!).
+     * This could be used in the future for the system to determine whether your usermod is installed.
+     */
+    uint16_t getId()
+    {
+        return USERMOD_ID_MODE_SORT;
+    }
+};