#include "ui.h"

#include "host_info.h"
#include "pins.h"

#include <Arduino.h>
#include <cstdio>
#include <lvgl.h>

static constexpr uint32_t COL_BG = 0x0B121A;
static constexpr uint32_t COL_INK = 0xE8EEF4;
static constexpr uint32_t COL_MUTED = 0x7A8B9C;
static constexpr uint32_t COL_LINE = 0x1A2734;
static constexpr uint32_t COL_OK = 0x3DDC97;
static constexpr uint32_t COL_WARN = 0xE8B84A;
static constexpr uint32_t COL_BAD = 0xE85D4C;
static constexpr uint32_t COL_ACCENT = 0x4FC3F7;
static constexpr uint32_t COL_BAR_BG = 0x162230;

struct MetricRow {
  lv_obj_t *lbl_tag;
  lv_obj_t *lbl_name;
  lv_obj_t *lbl_pct;
  lv_obj_t *bar;
};

static lv_obj_t *scr = nullptr;
static lv_obj_t *lbl_title = nullptr;
static lv_obj_t *lbl_host = nullptr;
static lv_obj_t *lbl_status = nullptr;
static MetricRow row_cpu = {};
static MetricRow row_gpu = {};
static MetricRow row_ram = {};
static MetricRow row_disk = {};
static uint32_t last_paint_ms = 0;

static int pct_of(float used, float total) {
  if (total <= 0.01f) {
    return 0;
  }
  int p = (int)((used * 100.0f) / total + 0.5f);
  if (p < 0) {
    p = 0;
  }
  if (p > 100) {
    p = 100;
  }
  return p;
}

static uint32_t color_for_pct(int pct) {
  if (pct >= 85) {
    return COL_BAD;
  }
  if (pct >= 65) {
    return COL_WARN;
  }
  return COL_OK;
}

static void style_bar(lv_obj_t *bar) {
  lv_obj_set_style_bg_color(bar, lv_color_hex(COL_BAR_BG), LV_PART_MAIN);
  lv_obj_set_style_bg_opa(bar, LV_OPA_COVER, LV_PART_MAIN);
  lv_obj_set_style_radius(bar, 4, LV_PART_MAIN);
  lv_obj_set_style_pad_all(bar, 0, LV_PART_MAIN);
  lv_obj_set_style_bg_color(bar, lv_color_hex(COL_OK), LV_PART_INDICATOR);
  lv_obj_set_style_bg_opa(bar, LV_OPA_COVER, LV_PART_INDICATOR);
  lv_obj_set_style_radius(bar, 4, LV_PART_INDICATOR);
  lv_bar_set_range(bar, 0, 100);
  lv_bar_set_value(bar, 0, LV_ANIM_OFF);
}

static MetricRow make_row(lv_obj_t *parent, const char *tag, int y) {
  MetricRow r = {};

  r.lbl_tag = lv_label_create(parent);
  lv_label_set_text(r.lbl_tag, tag);
  lv_obj_set_style_text_color(r.lbl_tag, lv_color_hex(COL_ACCENT), 0);
  lv_obj_set_style_text_font(r.lbl_tag, &lv_font_montserrat_14, 0);
  lv_obj_set_pos(r.lbl_tag, UX(8), UY(y));

  r.lbl_name = lv_label_create(parent);
  lv_label_set_text(r.lbl_name, "—");
  lv_label_set_long_mode(r.lbl_name, LV_LABEL_LONG_DOT);
  lv_obj_set_width(r.lbl_name, UW(190));
  lv_obj_set_style_text_color(r.lbl_name, lv_color_hex(COL_INK), 0);
  lv_obj_set_style_text_font(r.lbl_name, &lv_font_montserrat_14, 0);
  lv_obj_set_pos(r.lbl_name, UX(52), UY(y));

  r.lbl_pct = lv_label_create(parent);
  lv_label_set_text(r.lbl_pct, "--%");
  lv_obj_set_style_text_color(r.lbl_pct, lv_color_hex(COL_MUTED), 0);
  lv_obj_set_style_text_font(r.lbl_pct, &lv_font_montserrat_14, 0);
  lv_obj_align(r.lbl_pct, LV_ALIGN_TOP_RIGHT, UX(-8), UY(y));

  r.bar = lv_bar_create(parent);
  lv_obj_set_size(r.bar, UI_HOR_RES - UW(16), UH(10));
  lv_obj_set_pos(r.bar, UX(8), UY(y + 18));
  style_bar(r.bar);

  return r;
}

static void set_row_pct(MetricRow &r, int pct, const char *name, const char *right) {
  if (r.lbl_name && name) {
    lv_label_set_text(r.lbl_name, name);
  }
  if (r.lbl_pct && right) {
    lv_label_set_text(r.lbl_pct, right);
    lv_obj_set_style_text_color(r.lbl_pct, lv_color_hex(color_for_pct(pct)), 0);
  }
  if (r.bar) {
    lv_bar_set_value(r.bar, pct, LV_ANIM_OFF);
    lv_obj_set_style_bg_color(r.bar, lv_color_hex(color_for_pct(pct)),
                              LV_PART_INDICATOR);
  }
}

void ui_create() {
  scr = lv_obj_create(nullptr);
  lv_obj_set_style_bg_color(scr, lv_color_hex(COL_BG), 0);
  lv_obj_set_style_bg_opa(scr, LV_OPA_COVER, 0);
  lv_obj_clear_flag(scr, LV_OBJ_FLAG_SCROLLABLE);
  lv_screen_load(scr);

  lbl_title = lv_label_create(scr);
  lv_label_set_text(lbl_title, "PC Monitor");
  lv_obj_set_style_text_color(lbl_title, lv_color_hex(COL_INK), 0);
  lv_obj_set_style_text_font(lbl_title, &lv_font_montserrat_18, 0);
  lv_obj_set_pos(lbl_title, UX(8), UY(6));

  lbl_status = lv_label_create(scr);
  lv_label_set_text(lbl_status, "waiting");
  lv_obj_set_style_text_color(lbl_status, lv_color_hex(COL_WARN), 0);
  lv_obj_set_style_text_font(lbl_status, &lv_font_montserrat_14, 0);
  lv_obj_align(lbl_status, LV_ALIGN_TOP_RIGHT, UX(-8), UY(8));

  lbl_host = lv_label_create(scr);
  lv_label_set_text(lbl_host, "Connect USB + run host script");
  lv_label_set_long_mode(lbl_host, LV_LABEL_LONG_DOT);
  lv_obj_set_width(lbl_host, UI_HOR_RES - UW(16));
  lv_obj_set_style_text_color(lbl_host, lv_color_hex(COL_MUTED), 0);
  lv_obj_set_style_text_font(lbl_host, &lv_font_montserrat_14, 0);
  lv_obj_set_pos(lbl_host, UX(8), UY(28));

  lv_obj_t *line = lv_obj_create(scr);
  lv_obj_set_size(line, UI_HOR_RES - UW(16), 1);
  lv_obj_set_pos(line, UX(8), UY(48));
  lv_obj_set_style_bg_color(line, lv_color_hex(COL_LINE), 0);
  lv_obj_set_style_bg_opa(line, LV_OPA_COVER, 0);
  lv_obj_set_style_border_width(line, 0, 0);
  lv_obj_set_style_pad_all(line, 0, 0);
  lv_obj_clear_flag(line, LV_OBJ_FLAG_SCROLLABLE);

  row_cpu = make_row(scr, "CPU", 56);
  row_gpu = make_row(scr, "GPU", 96);
  row_ram = make_row(scr, "RAM", 136);
  row_disk = make_row(scr, "DISK", 176);

  last_paint_ms = 0;
}

static void paint() {
  const HostInfo &h = host_info_get();
  const bool live = host_info_is_live(5000);

  if (lbl_status) {
    if (!h.valid) {
      lv_label_set_text(lbl_status, "waiting");
      lv_obj_set_style_text_color(lbl_status, lv_color_hex(COL_WARN), 0);
    } else if (live) {
      lv_label_set_text(lbl_status, "live");
      lv_obj_set_style_text_color(lbl_status, lv_color_hex(COL_OK), 0);
    } else {
      lv_label_set_text(lbl_status, "stale");
      lv_obj_set_style_text_color(lbl_status, lv_color_hex(COL_BAD), 0);
    }
  }

  if (!h.valid) {
    return;
  }

  if (lbl_host) {
    lv_label_set_text(lbl_host, h.host[0] ? h.host : "(unknown host)");
  }

  char buf[48];

  int cpu_pct = (int)(h.cpu_pct + 0.5f);
  snprintf(buf, sizeof(buf), "%d%%", cpu_pct);
  set_row_pct(row_cpu, cpu_pct, h.cpu[0] ? h.cpu : "CPU", buf);

  if (h.gpu_pct < 0) {
    set_row_pct(row_gpu, 0, h.gpu[0] ? h.gpu : "GPU", "n/a");
    if (row_gpu.lbl_pct) {
      lv_obj_set_style_text_color(row_gpu.lbl_pct, lv_color_hex(COL_MUTED), 0);
    }
  } else {
    int gpu_pct = (int)(h.gpu_pct + 0.5f);
    snprintf(buf, sizeof(buf), "%d%%", gpu_pct);
    set_row_pct(row_gpu, gpu_pct, h.gpu[0] ? h.gpu : "GPU", buf);
  }

  int ram_pct = pct_of(h.ram_used_gb, h.ram_total_gb);
  snprintf(buf, sizeof(buf), "%.1f/%.0fG", (double)h.ram_used_gb,
           (double)h.ram_total_gb);
  set_row_pct(row_ram, ram_pct, "Memory", buf);

  int disk_pct = pct_of(h.disk_used_gb, h.disk_total_gb);
  snprintf(buf, sizeof(buf), "%.0f/%.0fG", (double)h.disk_used_gb,
           (double)h.disk_total_gb);
  set_row_pct(row_disk, disk_pct, "System drive", buf);
}

void ui_tick() {
  const uint32_t now = millis();
  if (now - last_paint_ms < 200) {
    return;
  }
  last_paint_ms = now;
  paint();
}