/*

SSD1306 - Screen module

Copyright (C) 2018 by Xose Pérez <xose dot perez at gmail dot com>


This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <OLEDDisplay.h>
#include <Wire.h>

#include "GPS.h"
#include "NodeDB.h"
#include "configuration.h"
#include "fonts.h"
#include "images.h"
#include "main.h"
#include "mesh-pb-constants.h"
#include "screen.h"

#define FONT_HEIGHT 14 // actually 13 for "ariel 10" but want a little extra space
#define FONT_HEIGHT_16 (ArialMT_Plain_16[1] + 1)
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define TRANSITION_FRAMERATE 30 // fps
#define IDLE_FRAMERATE 10       // in fps
#define COMPASS_DIAM 44

#define NUM_EXTRA_FRAMES 2 // text message and debug frame

namespace meshtastic
{

// A text message frame + debug frame + all the node infos
static FrameCallback normalFrames[MAX_NUM_NODES + NUM_EXTRA_FRAMES];
static uint32_t targetFramerate = IDLE_FRAMERATE;
static char btPIN[16] = "888888";

static void drawBootScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    // draw an xbm image.
    // Please note that everything that should be transitioned
    // needs to be drawn relative to x and y

    display->drawXbm(x + 32, y, icon_width, icon_height, (const uint8_t *)icon_bits);

    display->setFont(ArialMT_Plain_16);
    display->setTextAlignment(TEXT_ALIGN_CENTER);
    display->drawString(64 + x, SCREEN_HEIGHT - FONT_HEIGHT_16, "meshtastic.org");
}

static void drawFrameBluetooth(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    display->setTextAlignment(TEXT_ALIGN_CENTER);
    display->setFont(ArialMT_Plain_16);
    display->drawString(64 + x, 2 + y, "Bluetooth");

    display->setFont(ArialMT_Plain_10);
    display->drawString(64 + x, SCREEN_HEIGHT - FONT_HEIGHT + y, "Enter this code");

    display->setTextAlignment(TEXT_ALIGN_CENTER);
    display->setFont(ArialMT_Plain_24);
    display->drawString(64 + x, 22 + y, btPIN);
}

/// Draw the last text message we received
static void drawTextMessageFrame(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    MeshPacket &mp = devicestate.rx_text_message;
    NodeInfo *node = nodeDB.getNode(mp.from);
    // DEBUG_MSG("drawing text message from 0x%x: %s\n", mp.from,
    // mp.payload.variant.data.payload.bytes);

    // Demo for drawStringMaxWidth:
    // with the third parameter you can define the width after which words will
    // be wrapped. Currently only spaces and "-" are allowed for wrapping
    display->setTextAlignment(TEXT_ALIGN_LEFT);
    display->setFont(ArialMT_Plain_16);
    String sender = (node && node->has_user) ? node->user.short_name : "???";
    display->drawString(0 + x, 0 + y, sender);
    display->setFont(ArialMT_Plain_10);

    // the max length of this buffer is much longer than we can possibly print
    static char tempBuf[96];
    snprintf(tempBuf, sizeof(tempBuf), "         %s", mp.payload.variant.data.payload.bytes);

    display->drawStringMaxWidth(4 + x, 10 + y, 128, tempBuf);
}

/// Draw a series of fields in a column, wrapping to multiple colums if needed
static void drawColumns(OLEDDisplay *display, int16_t x, int16_t y, const char **fields)
{
    // The coordinates define the left starting point of the text
    display->setTextAlignment(TEXT_ALIGN_LEFT);

    const char **f = fields;
    int xo = x, yo = y;
    while (*f) {
        display->drawString(xo, yo, *f);
        yo += FONT_HEIGHT;
        if (yo > SCREEN_HEIGHT - FONT_HEIGHT) {
            xo += SCREEN_WIDTH / 2;
            yo = 0;
        }
        f++;
    }
}

/// Draw a series of fields in a row, wrapping to multiple rows if needed
/// @return the max y we ended up printing to
static uint32_t drawRows(OLEDDisplay *display, int16_t x, int16_t y, const char **fields)
{
    // The coordinates define the left starting point of the text
    display->setTextAlignment(TEXT_ALIGN_LEFT);

    const char **f = fields;
    int xo = x, yo = y;
    const int COLUMNS = 2; // hardwired for two columns per row....
    int col = 0;           // track which column we are on
    while (*f) {
        display->drawString(xo, yo, *f);
        xo += SCREEN_WIDTH / COLUMNS;
        // Wrap to next row, if needed.
        if (++col >= COLUMNS) {
            xo = x;
            yo += FONT_HEIGHT;
            col = 0;
        }
        f++;
    }
    if (col != 0) {
        // Include last incomplete line in our total.
        yo += FONT_HEIGHT;
    }

    return yo;
}

/// Ported from my old java code, returns distance in meters along the globe
/// surface (by magic?)
static float latLongToMeter(double lat_a, double lng_a, double lat_b, double lng_b)
{
    double pk = (180 / 3.14169);
    double a1 = lat_a / pk;
    double a2 = lng_a / pk;
    double b1 = lat_b / pk;
    double b2 = lng_b / pk;
    double cos_b1 = cos(b1);
    double cos_a1 = cos(a1);
    double t1 = cos_a1 * cos(a2) * cos_b1 * cos(b2);
    double t2 = cos_a1 * sin(a2) * cos_b1 * sin(b2);
    double t3 = sin(a1) * sin(b1);
    double tt = acos(t1 + t2 + t3);
    if (isnan(tt))
        tt = 0.0; // Must have been the same point?

    return (float)(6366000 * tt);
}

static inline double toRadians(double deg)
{
    return deg * PI / 180;
}

static inline double toDegrees(double r)
{
    return r * 180 / PI;
}

/**
 * Computes the bearing in degrees between two points on Earth.  Ported from my
 * old Gaggle android app.
 *
 * @param lat1
 * Latitude of the first point
 * @param lon1
 * Longitude of the first point
 * @param lat2
 * Latitude of the second point
 * @param lon2
 * Longitude of the second point
 * @return Bearing between the two points in radians. A value of 0 means due
 * north.
 */
static float bearing(double lat1, double lon1, double lat2, double lon2)
{
    double lat1Rad = toRadians(lat1);
    double lat2Rad = toRadians(lat2);
    double deltaLonRad = toRadians(lon2 - lon1);
    double y = sin(deltaLonRad) * cos(lat2Rad);
    double x = cos(lat1Rad) * sin(lat2Rad) - (sin(lat1Rad) * cos(lat2Rad) * cos(deltaLonRad));
    return atan2(y, x);
}

namespace
{

/// A basic 2D point class for drawing
class Point
{
  public:
    float x, y;

    Point(float _x, float _y) : x(_x), y(_y) {}

    /// Apply a rotation around zero (standard rotation matrix math)
    void rotate(float radian)
    {
        float cos = cosf(radian), sin = sinf(radian);
        float rx = x * cos - y * sin, ry = x * sin + y * cos;

        x = rx;
        y = ry;
    }

    void translate(int16_t dx, int dy)
    {
        x += dx;
        y += dy;
    }

    void scale(float f)
    {
        x *= f;
        y *= f;
    }
};

} // namespace

static void drawLine(OLEDDisplay *d, const Point &p1, const Point &p2)
{
    d->drawLine(p1.x, p1.y, p2.x, p2.y);
}

/**
 * Given a recent lat/lon return a guess of the heading the user is walking on.
 *
 * We keep a series of "after you've gone 10 meters, what is your heading since
 * the last reference point?"
 */
static float estimatedHeading(double lat, double lon)
{
    static double oldLat, oldLon;
    static float b;

    if (oldLat == 0) {
        // just prepare for next time
        oldLat = lat;
        oldLon = lon;

        return b;
    }

    float d = latLongToMeter(oldLat, oldLon, lat, lon);
    if (d < 10) // haven't moved enough, just keep current bearing
        return b;

    b = bearing(oldLat, oldLon, lat, lon);
    oldLat = lat;
    oldLon = lon;

    return b;
}

/// Sometimes we will have Position objects that only have a time, so check for
/// valid lat/lon
static bool hasPosition(NodeInfo *n)
{
    return n->has_position && (n->position.latitude != 0 || n->position.longitude != 0);
}

/// We will skip one node - the one for us, so we just blindly loop over all
/// nodes
static size_t nodeIndex;
static int8_t prevFrame = -1;

static void drawNodeInfo(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    // We only advance our nodeIndex if the frame # has changed - because
    // drawNodeInfo will be called repeatedly while the frame is shown
    if (state->currentFrame != prevFrame) {
        prevFrame = state->currentFrame;

        nodeIndex = (nodeIndex + 1) % nodeDB.getNumNodes();
        NodeInfo *n = nodeDB.getNodeByIndex(nodeIndex);
        if (n->num == nodeDB.getNodeNum()) {
            // Don't show our node, just skip to next
            nodeIndex = (nodeIndex + 1) % nodeDB.getNumNodes();
        }
    }

    NodeInfo *node = nodeDB.getNodeByIndex(nodeIndex);

    display->setFont(ArialMT_Plain_10);

    // The coordinates define the left starting point of the text
    display->setTextAlignment(TEXT_ALIGN_LEFT);

    const char *username = node->has_user ? node->user.long_name : "Unknown Name";

    static char signalStr[20];
    snprintf(signalStr, sizeof(signalStr), "Signal: %d", node->snr);

    uint32_t agoSecs = sinceLastSeen(node);
    static char lastStr[20];
    if (agoSecs < 120) // last 2 mins?
        snprintf(lastStr, sizeof(lastStr), "%d seconds ago", agoSecs);
    else if (agoSecs < 120 * 60) // last 2 hrs
        snprintf(lastStr, sizeof(lastStr), "%d minutes ago", agoSecs / 60);
    else
        snprintf(lastStr, sizeof(lastStr), "%d hours ago", agoSecs / 60 / 60);

    static float simRadian;
    simRadian += 0.1; // For testing, have the compass spin unless both
                      // locations are valid

    static char distStr[20];
    *distStr = 0; // might not have location data
    float headingRadian = simRadian;
    NodeInfo *ourNode = nodeDB.getNode(nodeDB.getNodeNum());
    if (ourNode && hasPosition(ourNode) && hasPosition(node)) {
        Position &op = ourNode->position, &p = node->position;
        float d = latLongToMeter(p.latitude, p.longitude, op.latitude, op.longitude);
        if (d < 2000)
            snprintf(distStr, sizeof(distStr), "%.0f m", d);
        else
            snprintf(distStr, sizeof(distStr), "%.1f km", d / 1000);

        // FIXME, also keep the guess at the operators heading and add/substract
        // it.  currently we don't do this and instead draw north up only.
        float bearingToOther = bearing(p.latitude, p.longitude, op.latitude, op.longitude);
        float myHeading = estimatedHeading(p.latitude, p.longitude);
        headingRadian = bearingToOther - myHeading;
    } else {
        // Debug info for gps lock errors
        // DEBUG_MSG("ourNode %d, ourPos %d, theirPos %d\n", !!ourNode, ourNode && hasPosition(ourNode), hasPosition(node));
    }

    const char *fields[] = {username, distStr, signalStr, lastStr, NULL};
    drawColumns(display, x, y, fields);

    // coordinates for the center of the compass
    int16_t compassX = x + SCREEN_WIDTH - COMPASS_DIAM / 2 - 1, compassY = y + SCREEN_HEIGHT / 2;
    // display->drawXbm(compassX, compassY, compass_width, compass_height,
    // (const uint8_t *)compass_bits);

    Point tip(0.0f, 0.5f), tail(0.0f, -0.5f); // pointing up initially
    float arrowOffsetX = 0.2f, arrowOffsetY = 0.2f;
    Point leftArrow(tip.x - arrowOffsetX, tip.y - arrowOffsetY), rightArrow(tip.x + arrowOffsetX, tip.y - arrowOffsetY);

    Point *points[] = {&tip, &tail, &leftArrow, &rightArrow};

    for (int i = 0; i < 4; i++) {
        points[i]->rotate(headingRadian);
        points[i]->scale(COMPASS_DIAM * 0.6);
        points[i]->translate(compassX, compassY);
    }
    drawLine(display, tip, tail);
    drawLine(display, leftArrow, tip);
    drawLine(display, rightArrow, tip);

    display->drawCircle(compassX, compassY, COMPASS_DIAM / 2);
}

#if 0
void _screen_header()
{
    if (!disp)
        return;


    // Message count
    //snprintf(buffer, sizeof(buffer), "#%03d", ttn_get_count() % 1000);
    //display->setTextAlignment(TEXT_ALIGN_LEFT);
    //display->drawString(0, 2, buffer);

    // Datetime
    display->setTextAlignment(TEXT_ALIGN_CENTER);
    display->drawString(display->getWidth()/2, 2, gps.getTimeStr());

    // Satellite count
    display->setTextAlignment(TEXT_ALIGN_RIGHT);
    char buffer[10];
    display->drawString(display->getWidth() - SATELLITE_IMAGE_WIDTH - 4, 2, itoa(gps.satellites.value(), buffer, 10));
    display->drawXbm(display->getWidth() - SATELLITE_IMAGE_WIDTH, 0, SATELLITE_IMAGE_WIDTH, SATELLITE_IMAGE_HEIGHT, SATELLITE_IMAGE);
}
#endif

Screen::Screen(uint8_t address, uint8_t sda, uint8_t scl) : cmdQueue(32), dispdev(address, sda, scl), ui(&dispdev) {}

void Screen::handleSetOn(bool on)
{
    if (!useDisplay)
        return;

    if (on != screenOn) {
        if (on) {
            DEBUG_MSG("Turning on screen\n");
            dispdev.displayOn();
        } else {
            DEBUG_MSG("Turning off screen\n");
            dispdev.displayOff();
        }
        screenOn = on;
    }
}

void Screen::setup()
{
    // We don't set useDisplay until setup() is called, because some boards have a declaration of this object but the device
    // is never found when probing i2c and therefore we don't call setup and never want to do (invalid) accesses to this device.
    useDisplay = true;

    dispdev.resetOrientation();

    // Initialising the UI will init the display too.
    ui.init();
    ui.setTimePerTransition(300); // msecs
    ui.setIndicatorPosition(BOTTOM);
    // Defines where the first frame is located in the bar.
    ui.setIndicatorDirection(LEFT_RIGHT);
    ui.setFrameAnimation(SLIDE_LEFT);
    // Don't show the page swipe dots while in boot screen.
    ui.disableAllIndicators();
    // Store a pointer to Screen so we can get to it from static functions.
    ui.getUiState()->userData = this;

    // Add frames.
    static FrameCallback bootFrames[] = {drawBootScreen};
    static const int bootFrameCount = sizeof(bootFrames) / sizeof(bootFrames[0]);
    ui.setFrames(bootFrames, bootFrameCount);
    // No overlays.
    ui.setOverlays(nullptr, 0);

    // Require presses to switch between frames.
    ui.disableAutoTransition();

    // Set up a log buffer with 3 lines, 32 chars each.
    dispdev.setLogBuffer(3, 32);

#ifdef FLIP_SCREEN_VERTICALLY
    dispdev.flipScreenVertically();
#endif

    // Turn on the display.
    handleSetOn(true);

    // On some ssd1306 clones, the first draw command is discarded, so draw it
    // twice initially.
    ui.update();
    ui.update();
}

void Screen::doTask()
{
    // If we don't have a screen, don't ever spend any CPU for us.
    if (!useDisplay) {
        setPeriod(0);
        return;
    }

    // Process incoming commands.
    for (;;) {
        CmdItem cmd;
        if (!cmdQueue.dequeue(&cmd, 0)) {
            break;
        }
        switch (cmd.cmd) {
        case Cmd::SET_ON:
            handleSetOn(true);
            break;
        case Cmd::SET_OFF:
            handleSetOn(false);
            break;
        case Cmd::ON_PRESS:
            handleOnPress();
            break;
        case Cmd::START_BLUETOOTH_PIN_SCREEN:
            handleStartBluetoothPinScreen(cmd.bluetooth_pin);
            break;
        case Cmd::STOP_BLUETOOTH_PIN_SCREEN:
        case Cmd::STOP_BOOT_SCREEN:
            setFrames();
            break;
        case Cmd::PRINT:
            handlePrint(cmd.print_text);
            free(cmd.print_text);
            break;
        default:
            DEBUG_MSG("BUG: invalid cmd");
        }
    }

    if (!screenOn) { // If we didn't just wake and the screen is still off, then
                     // stop updating until it is on again
        setPeriod(0);
        return;
    }

    // Switch to a low framerate (to save CPU) when we are not in transition
    // but we should only call setTargetFPS when framestate changes, because
    // otherwise that breaks animations.
    if (targetFramerate != IDLE_FRAMERATE && ui.getUiState()->frameState == FIXED) {
        // oldFrameState = ui.getUiState()->frameState;
        DEBUG_MSG("Setting idle framerate\n");
        targetFramerate = IDLE_FRAMERATE;
        ui.setTargetFPS(targetFramerate);
    }

    // While showing the bootscreen or Bluetooth pair screen all of our
    // standard screen switching is stopped.
    if (showingNormalScreen) {
        // TODO(girts): decouple nodeDB from screen.
        // standard screen loop handling ehre
        // If the # nodes changes, we need to regen our list of screens
        if (nodeDB.updateGUI || nodeDB.updateTextMessage) {
            setFrames();
            nodeDB.updateGUI = false;
            nodeDB.updateTextMessage = false;
        }
    }

    ui.update();

    // DEBUG_MSG("want fps %d, fixed=%d\n", targetFramerate,
    // ui.getUiState()->frameState); If we are scrolling we need to be called
    // soon, otherwise just 1 fps (to save CPU) We also ask to be called twice
    // as fast as we really need so that any rounding errors still result with
    // the correct framerate
    setPeriod(1000 / targetFramerate);
}

void Screen::drawDebugInfoTrampoline(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    Screen *screen = reinterpret_cast<Screen *>(state->userData);
    screen->debugInfo.drawFrame(display, state, x, y);
}

// restore our regular frame list
void Screen::setFrames()
{
    DEBUG_MSG("showing standard frames\n");
    showingNormalScreen = true;

    size_t numnodes = nodeDB.getNumNodes();
    // We don't show the node info our our node (if we have it yet - we should)
    if (numnodes > 0)
        numnodes--;

    size_t numframes = 0;

    // If we have a text message - show it first
    if (devicestate.has_rx_text_message)
        normalFrames[numframes++] = drawTextMessageFrame;

    // then all the nodes
    for (size_t i = 0; i < numnodes; i++)
        normalFrames[numframes++] = drawNodeInfo;

    // then the debug info
    //
    // Since frames are basic function pointers, we have to use a helper to
    // call a method on debugInfo object.
    normalFrames[numframes++] = &Screen::drawDebugInfoTrampoline;

    ui.setFrames(normalFrames, numframes);
    ui.enableAllIndicators();

    prevFrame = -1; // Force drawNodeInfo to pick a new node (because our list
                    // just changed)
}

void Screen::handleStartBluetoothPinScreen(uint32_t pin)
{
    DEBUG_MSG("showing bluetooth screen\n");
    showingNormalScreen = false;

    static FrameCallback btFrames[] = {drawFrameBluetooth};

    snprintf(btPIN, sizeof(btPIN), "%06d", pin);

    ui.disableAllIndicators();
    ui.setFrames(btFrames, 1);
}

void Screen::handlePrint(const char *text)
{
    DEBUG_MSG("Screen: %s", text);
    if (!useDisplay)
        return;

    dispdev.print(text);
}

void Screen::handleOnPress()
{
    // If screen was off, just wake it, otherwise advance to next frame
    // If we are in a transition, the press must have bounced, drop it.
    if (ui.getUiState()->frameState == FIXED) {
        setPeriod(1); // redraw ASAP
        ui.nextFrame();

        DEBUG_MSG("Setting fast framerate\n");

        // We are about to start a transition so speed up fps
        targetFramerate = TRANSITION_FRAMERATE;
        ui.setTargetFPS(targetFramerate);
    }
}

void DebugInfo::drawFrame(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
{
    display->setFont(ArialMT_Plain_10);

    // The coordinates define the left starting point of the text
    display->setTextAlignment(TEXT_ALIGN_LEFT);

    char usersStr[20];
    char channelStr[20];
    char batStr[20];
    char gpsStr[20];
    {
        LockGuard guard(&lock);
        snprintf(usersStr, sizeof(usersStr), "Users %d/%d", nodesOnline, nodesTotal);
        snprintf(channelStr, sizeof(channelStr), "%s", channelName.c_str());
        if (powerStatus.haveBattery) {
            // TODO: draw a battery icon instead of letter "B".
            int batV = powerStatus.batteryVoltageMv / 1000;
            int batCv = (powerStatus.batteryVoltageMv % 1000) / 10;
            snprintf(batStr, sizeof(batStr), "B %01d.%02dV%c%c", batV, batCv, powerStatus.charging ? '+' : ' ',
                     powerStatus.usb ? 'U' : ' ');
        } else {
            snprintf(batStr, sizeof(batStr), "%s", powerStatus.usb ? "USB" : "");
        }

        if (!gpsStatus.empty()) {
            snprintf(gpsStr, sizeof(gpsStr), "GPS %s", gpsStatus.c_str());
        } else {
            gpsStr[0] = '\0'; // Just show empty string.
        }
    }

    const char *fields[] = {batStr, gpsStr, usersStr, channelStr, nullptr};
    uint32_t yo = drawRows(display, x, y, fields);

    display->drawLogBuffer(x, yo);
}

} // namespace meshtastic