#include "lora_scanner_app.h"

#include <Arduino.h>

#include <algorithm>
#include <cstdio>
#include <ctime>

#include "meshtastic_presets.h"
#include "packet_view.h"
#include "sweep_view.h"
#include "ui/canvas.h"
#include "ui/fonts.h"
#include "ui/widgets.h"

namespace roro {

namespace {
constexpr uint32_t kMessageMs = 4000;
}

void LoraScannerApp::onEnter() {
    int i = std::clamp<int>(settings_.getInt(Setting::LoraPreset), 0, meshtastic::kEu868PresetCount - 1);
    const meshtastic::Preset& p = meshtastic::kEu868Presets[i];
    if (std::string(radio_.config().name) != p.name) radio_.setPreset(p);
    radio_.listen(RadioService::App, true);
    view_ = View::Packets;
    selectedSeq_ = 0;
    followNewest_ = true;
    shownSeq_ = 0;
    requestRedraw();
}

void LoraScannerApp::onExit() {
    showSweep(false);
    radio_.listen(RadioService::App, false);
}

void LoraScannerApp::showSweep(bool on) {
    if (on == (view_ == View::Sweep)) return;
    radio_.sweep(on);
    view_ = on ? View::Sweep : View::Packets;
    peak_.clear();
    std::vector<int8_t>().swap(waterfall_);  // its memory only while shown
    sweepSteps_ = 0;
    shownSweep_ = radio_.sweeps();
    requestRedraw();
}

bool LoraScannerApp::meshtasticSettings() const { return radio_.config().syncWord == meshtastic::kSyncWord; }

void LoraScannerApp::say(const std::string& text) {
    message_ = text;
    messageMs_ = millis();
    requestRedraw();
}

bool LoraScannerApp::onKey(const KeyEvent& e) {
    if (e.key == Key::Tab && (view_ == View::Packets || view_ == View::Sweep)) {
        showSweep(view_ == View::Packets);
        return true;
    }
    if (view_ == View::Sweep) {
        if (e.key == Key::Back) {
            showSweep(false);
            return true;
        }
        return e.key != Key::Home;  // everything else stays here
    }
    if (view_ == View::Details) {
        int last = std::max<int>(0, static_cast<int>(details_.size()) - 8);
        if (e.key == Key::Up) detailsTop_ = std::max(0, detailsTop_ - 1);
        else if (e.key == Key::Down) detailsTop_ = std::min(last, detailsTop_ + 1);
        else if (e.key == Key::Back || e.key == Key::Select) view_ = View::Packets;
        else return true;
        requestRedraw();
        return true;
    }
    if (view_ == View::Presets) {
        if (e.key == Key::Up) presets_.up();
        else if (e.key == Key::Down) presets_.down();
        else if (e.key == Key::Select) {
            int i = presets_.selected();
            settings_.setInt(Setting::LoraPreset, i);
            radio_.setPreset(meshtastic::kEu868Presets[i]);
            say(std::string("Listening on ") + meshtastic::kEu868Presets[i].name);
            view_ = View::Packets;
        } else if (e.key == Key::Back) view_ = View::Packets;
        else return true;
        requestRedraw();
        return true;
    }
    // The packet list.
    if (e.key == Key::Up || e.key == Key::Down) {
        e.key == Key::Up ? packets_.up() : packets_.down();
        selectedSeq_ = packets_.selected() >= 0 ? radio_.received() - packets_.selected() : 0;
        followNewest_ = packets_.selected() <= 0;
        requestRedraw();
        return true;
    }
    if (e.key == Key::Select) {
        openDetails();
        return true;
    }
    if (e.key == Key::Char && (e.ch == 'p' || e.ch == 'P')) {
        presets_.setCount(meshtastic::kEu868PresetCount);
        presets_.select(settings_.getInt(Setting::LoraPreset));
        view_ = View::Presets;
        requestRedraw();
        return true;
    }
    if (e.key == Key::Char && (e.ch == 'c' || e.ch == 'C')) {
        if (capture_.capturing()) capture_.stop();
        else {
            std::string why = capture_.start(millis());
            if (!why.empty()) say(why);
        }
        requestRedraw();
        return true;
    }
    return false;  // Back leaves the App
}

void LoraScannerApp::openDetails() {
    RadioPacket p;
    if (!selectedSeq_ || !radio_.packet(selectedSeq_, p)) return say("That packet has left the list");
    details_.clear();
    char line[64];
    std::snprintf(line, sizeof line, "%s, %u bytes%s", timeOf(p).c_str(), p.len, p.crcOk ? "" : ", bad CRC");
    details_.push_back(line);
    std::snprintf(line, sizeof line, "%.0f dBm, SNR %.1f dB, noise %.0f", p.rx.rssi, p.rx.snr, p.rx.noiseFloor);
    details_.push_back(line);
    std::snprintf(line, sizeof line, "%.4f MHz, off by %.0f Hz", p.rx.frequencyHz / 1e6, p.frequencyError);
    details_.push_back(line);
    if (meshtasticSettings())
        for (auto& l : lora::headerLines(p.data, p.len)) details_.push_back(l);
    for (auto& l : lora::hexDump(p.data, p.len)) details_.push_back(l);
    detailsTop_ = 0;
    view_ = View::Details;
    requestRedraw();
}

std::string LoraScannerApp::timeOf(const RadioPacket& p) const {
    int64_t now = clock_.utcNow();
    if (now < 0) {  // no Clock yet: how long ago
        char ago[16];
        std::snprintf(ago, sizeof ago, "-%lus", (unsigned long)((millis() - p.ms) / 1000));
        return ago;
    }
    time_t t = static_cast<time_t>(now - static_cast<int64_t>((millis() - p.ms) / 1000));
    struct tm local;
    localtime_r(&t, &local);
    char buf[12];
    std::snprintf(buf, sizeof buf, "%02d:%02d:%02d", local.tm_hour, local.tm_min, local.tm_sec);
    return buf;
}

void LoraScannerApp::update(uint32_t nowMs) {
    if (view_ == View::Sweep) {
        if (radio_.sweeps() != shownSweep_) requestRedraw();
        return;
    }
    if (radio_.received() != shownSeq_ || nowMs - lastDrawMs_ >= 1000 ||
        (!message_.empty() && nowMs - messageMs_ >= kMessageMs))
        requestRedraw();
}

void LoraScannerApp::draw(Canvas& c) {
    lastDrawMs_ = millis();
    c.setTextDatum(top_left);
    if (!radio_.present()) {
        c.setFont(&fonts::bold);
        c.setTextColor(theme::kWarning);
        c.drawString("No LoRa radio found", 4, theme::kContent.y + 4);
        c.setFont(&fonts::body);
        c.setTextColor(theme::kMuted);
        c.drawString("Is the Cap LoRa-1262 attached?", 4, theme::kContent.y + 22);
        return;
    }
    switch (view_) {
        case View::Packets: drawPackets(c); break;
        case View::Details: drawDetails(c); break;
        case View::Presets: drawPresets(c); break;
        case View::Sweep: drawSweep(c); break;
    }
}

void LoraScannerApp::drawPackets(Canvas& c) {
    const auto& area = theme::kContent;
    RadioService::Config cfg = radio_.config();
    uint32_t newest = radio_.received();
    shownSeq_ = newest;

    // What it's listening to, and the noise floor.
    char head[64];
    std::snprintf(head, sizeof head, "%s %.3f MHz, noise %.0f", cfg.name, cfg.frequencyHz / 1e6, radio_.noiseFloor());
    c.setFont(&fonts::small);
    c.setTextColor(radio_.listening() ? theme::kMuted : theme::kWarning);
    c.drawString(radio_.listening() ? head : "Starting the radio...", 4, area.y + 2);
    if (capture_.capturing()) {
        c.setTextDatum(top_right);
        c.setTextColor(theme::kWarning);
        c.drawString(("CAP " + std::to_string(capture_.packets())).c_str(), area.w - 3, area.y + 2);
        c.setTextDatum(top_left);
    }

    // The list, newest first; the selection stays on its packet as new ones arrive.
    int count = static_cast<int>(radio_.available());
    packets_.setCount(count);
    if (!followNewest_ && selectedSeq_ && newest >= selectedSeq_ && newest - selectedSeq_ < static_cast<uint32_t>(count))
        packets_.select(static_cast<int>(newest - selectedSeq_));
    else if (count > 0) {
        followNewest_ = true;
        packets_.select(0);
        selectedSeq_ = newest;
    }
    theme::Rect list{area.x, area.y + 12, area.w, kListRows * theme::kLineHeight};
    if (count == 0) {
        c.setFont(&fonts::body);
        c.setTextColor(theme::kMuted);
        c.drawString("No packets yet.", 4, list.y + 4);
        c.drawString(meshtasticSettings() ? "Meshtastic nodes in range show here." : "Custom settings.", 4,
                     list.y + 4 + theme::kLineHeight);
    } else {
        bool mesh = meshtasticSettings();
        widgets::list(c, packets_, list, [&](int i) {
            RadioPacket p;
            if (!radio_.packet(newest - i, p)) return std::string("(gone)");
            return lora::row({p.data, p.len, p.rx.rssi, p.rx.snr, p.crcOk, mesh}, timeOf(p));
        });
    }

    // Footer: a message for a few seconds, or the keys.
    c.setFont(&fonts::small);
    bool showMessage = !message_.empty() && millis() - messageMs_ < kMessageMs;
    c.setTextColor(showMessage ? theme::kWarning : theme::kMuted);
    std::string keys = std::string("Enter: details  p: preset  Tab: sweep  c: ") + (capture_.capturing() ? "stop" : "capture");
    c.drawString(showMessage ? message_.c_str() : keys.c_str(), 4, area.y + area.h - 9);
}

void LoraScannerApp::drawDetails(Canvas& c) {
    const auto& area = theme::kContent;
    widgets::textLines(c, details_, detailsTop_, {area.x + 2, area.y + 2, area.w - 2, area.h - 2});
}

void LoraScannerApp::drawPresets(Canvas& c) {
    const auto& area = theme::kContent;
    c.setFont(&fonts::small);
    c.setTextColor(theme::kMuted);
    c.drawString("Meshtastic presets allowed in EU868", 4, area.y + 2);
    widgets::list(
        c, presets_, {area.x, area.y + 12, area.w, (kListRows + 1) * theme::kLineHeight},
        [](int i) { return std::string(meshtastic::kEu868Presets[i].name); },
        [](int i) {
            char v[24];
            const auto& p = meshtastic::kEu868Presets[i];
            std::snprintf(v, sizeof v, "SF%u %.0fk %.3f", p.sf, p.bwKHz, meshtastic::eu868FrequencyHz(p) / 1e6);
            return std::string(v);
        });
}

}  // namespace roro

namespace roro {

// Sweep (Q98): bars of the latest pass with peak hold, the waterfall underneath (newest at the
// top), and where the Sniffer's preset sits in the band.
void LoraScannerApp::drawSweep(Canvas& c) {
    const auto& area = theme::kContent;
    constexpr int kLow = -120, kHigh = -60;  // the scale, dBm: about the chip's floor to a near signal
    SweepFrame f;
    bool have = radio_.sweepFrame(f) && f.seq != 0;
    c.setFont(&fonts::small);
    c.setTextColor(theme::kMuted);
    c.drawString("Sweep, the Sniffer is paused", 4, area.y + 2);
    if (!have) {
        c.drawString("Measuring...", 4, area.y + 20);
        return;
    }
    // Keep peak hold and the waterfall for this band.
    if (f.steps != sweepSteps_) {
        sweepSteps_ = f.steps;
        peak_.assign(f.steps, -127);
        waterfall_.assign(static_cast<size_t>(kWaterfallRows) * f.steps, -127);
    }
    if (f.seq != shownSweep_) {
        shownSweep_ = f.seq;
        for (uint16_t i = 0; i < f.steps; ++i) peak_[i] = std::max(peak_[i], f.dbm[i]);
        std::copy_backward(waterfall_.begin(), waterfall_.end() - f.steps, waterfall_.end());
        std::copy(f.dbm, f.dbm + f.steps, waterfall_.begin());
    }

    // Layout: up to 3 px a step, left-aligned after the scale.
    int x0 = 26, cell = std::max(1, std::min(3, (area.w - x0 - 2) / std::max<int>(1, f.steps)));
    int barTop = area.y + 12, barH = 46, barBottom = barTop + barH;
    auto height = [&](int dbm) { return std::clamp((dbm - kLow) * barH / (kHigh - kLow), 0, barH); };
    c.setTextColor(theme::kMuted);
    c.drawString("-60", 2, barTop - 1);
    c.drawString("-120", 0, barBottom - 7);
    for (uint16_t i = 0; i < f.steps; ++i) {
        int x = x0 + i * cell, h = height(f.dbm[i]);
        if (h > 0) c.fillRect(x, barBottom - h, std::max(1, cell - 1), h, theme::kAccent);
        int ph = height(peak_[i]);
        if (ph > 0) c.drawFastHLine(x, barBottom - ph, std::max(1, cell - 1), theme::kText);
    }
    // The Sniffer's frequency, when it's in the band.
    uint32_t hz = radio_.config().frequencyHz;
    if (hz >= f.fromHz && hz <= f.fromHz + (f.steps - 1) * f.stepHz) {
        int x = x0 + static_cast<int>((hz - f.fromHz) / f.stepHz) * cell + cell / 2;
        for (int y = barTop; y < barBottom; y += 3) c.drawPixel(x, y, theme::kMessage);
    }

    // The waterfall.
    int wfTop = barBottom + 2;
    for (int r = 0; r < kWaterfallRows; ++r)
        for (uint16_t i = 0; i < f.steps; ++i) {
            int8_t v = waterfall_[static_cast<size_t>(r) * f.steps + i];
            if (v > -127) c.fillRect(x0 + i * cell, wfTop + r, cell, 1, lora::heatColor(lora::heatLevel(v, kLow, kHigh)));
        }

    // The band's edges, its floor and its strongest signal.
    lora::SweepStats st = lora::summarize(f.dbm, f.steps, f.fromHz, f.stepHz);
    char line[64];
    int y = area.y + area.h - 9;
    std::snprintf(line, sizeof line, "%.1f", f.fromHz / 1e6);
    c.drawString(line, x0, wfTop + kWaterfallRows + 1);
    std::snprintf(line, sizeof line, "%.1f MHz", (f.fromHz + (f.steps - 1) * f.stepHz) / 1e6);
    c.setTextDatum(top_right);
    c.drawString(line, x0 + f.steps * cell, wfTop + kWaterfallRows + 1);
    c.setTextDatum(top_left);
    if (st.peaks.empty())
        std::snprintf(line, sizeof line, "floor %d dBm, nothing above it   Tab: sniffer", st.floor);
    else
        std::snprintf(line, sizeof line, "floor %d, %.1f MHz at %d dBm   Tab: sniffer", st.floor, st.peaks[0].hz / 1e6,
                      st.peaks[0].dbm);
    c.setTextColor(theme::kMuted);
    c.drawString(line, 4, y);
}

}  // namespace roro