#include <boost/test/unit_test.hpp>

#include <cmath>
#include <filesystem>
#include <fstream>
#include <map>
#include <string>

#include <boost/json/parse.hpp>
#include <boost/json/object.hpp>

#include <raylib.h>

#include <vamp_pico/screen.hpp>
#include <vamp_zero/menu_view.hpp>
#include <vamp_zero/page_control.hpp>


namespace {

auto read_bytes(std::filesystem::path const &path) -> std::string {
  auto input = std::ifstream{path, std::ios::binary};
  BOOST_REQUIRE(input.good());
  return {std::istreambuf_iterator<std::char_t>{input}, std::istreambuf_iterator<std::char_t>{}};
}

auto color(luma::color value) -> Color {
  return {value.r, value.g, value.b, value.a};
}

auto rectangle(luma::rect value) -> Rectangle {
  return {value.x, value.y, value.width, value.height};
}

// Uses the same raylib glyph rasterizer and metrics as Luma, without a GPU/window.

class image_context final : public luma::draw_context {
public:
  image_context() = default;
  ~image_context() override {
    UnloadImage(image);
    for (auto const &[size, font] : fonts_) {
      UnloadFontData(font.glyphs, font.glyphCount);
      MemFree(font.recs);
    }
  }
  auto fill_rect(luma::rect bounds, luma::color value) -> void override {
    ImageDrawRectangleRec(&image, rectangle(bounds), color(value));
  }
  auto stroke_rect(luma::rect bounds, std::float32_t thickness, luma::color value) -> void override {
    ImageDrawRectangleLines(&image, rectangle(bounds), static_cast<std::int32_t>(thickness), color(value));
  }
  auto stroke_line(luma::point from, luma::point to, std::float32_t thickness, luma::color value) -> void override {
    ImageDrawLineEx(&image, {from.x, from.y}, {to.x, to.y}, static_cast<std::int32_t>(thickness), color(value));
  }
  auto fill_ellipse(luma::rect bounds, luma::color value) -> void override {
    BOOST_TEST(bounds.width == bounds.height);
    ImageDrawCircle(&image, static_cast<std::int32_t>(bounds.x + bounds.width / 2.0F), static_cast<std::int32_t>(bounds.y + bounds.height / 2.0F), static_cast<std::int32_t>(bounds.width / 2.0F), color(value));
  }
  auto stroke_ellipse(luma::rect, std::float32_t, luma::color) -> void override {
    BOOST_FAIL("unexpected ellipse outline");
  }
  auto draw_texture(luma::texture const &, luma::rect, luma::rect, luma::color) -> void override {
    BOOST_FAIL("menu must not load score textures");
  }
  auto draw_text(std::string_view text, luma::point origin, luma::text_style const &style, luma::color value) -> void override {
    BOOST_TEST(style.font == vamp_style::ui_font_path);
    auto measured = measure_text(text, style);
    BOOST_REQUIRE(clip_.has_value());
    BOOST_TEST(measured.width <= clip_->width);
    BOOST_TEST(origin.y >= clip_->y);
    BOOST_TEST(origin.y + measured.height <= clip_->y + clip_->height);
    auto face = font(style.size);
    auto owned = std::string{text};
    auto x = origin.x;
    for (auto i = std::size_t{}; i < owned.size();) {
      auto bytes = std::int32_t{};
      auto codepoint = GetCodepointNext(owned.c_str() + i, &bytes);
      auto index = GetGlyphIndex(face, codepoint);
      auto const &glyph = face.glyphs[index];
      if (codepoint != ' ') {
        ImageDraw(&image, glyph.image, {0.0F, 0.0F, face.recs[index].width, face.recs[index].height}, {x + static_cast<std::float32_t>(glyph.offsetX), origin.y + static_cast<std::float32_t>(glyph.offsetY), face.recs[index].width, face.recs[index].height}, color(value));
      }
      x += (glyph.advanceX == 0 ? face.recs[index].width : static_cast<std::float32_t>(glyph.advanceX)) + 1.0F;
      i += static_cast<std::size_t>(bytes);
    }
  }
  auto push_clip(luma::rect bounds) -> void override {
    BOOST_TEST(bounds.x >= 0.0F);
    BOOST_TEST(bounds.y >= 0.0F);
    BOOST_TEST(bounds.x + bounds.width <= 1024.0F);
    BOOST_TEST(bounds.y + bounds.height <= 600.0F);
    clip_ = bounds;
  }
  auto pop_clip() -> void override {
    clip_.reset();
  }
  auto measure_text(std::string_view text, luma::text_style const &style) const -> luma::size override {
    auto size = MeasureTextEx(font(style.size), std::string{text}.c_str(), style.size, 1.0F);
    return {size.x, size.y};
  }
  Image image{GenImageColor(1024, 600, {vamp_style::background.r, vamp_style::background.g, vamp_style::background.b, 255})};
private:
  auto font(std::float32_t size) const -> Font {
    auto key = static_cast<std::int32_t>(std::ceil(size));
    auto found = fonts_.find(key);
    if (found != fonts_.end()) {
      return found->second;
    }
    auto bytes = read_bytes(std::filesystem::path{VAMP_TEST_SOURCE_DIR} / "package/assets/fonts/petaluma/PetalumaScript.otf");
    auto face = Font{};
    face.baseSize = key;
    face.glyphs = LoadFontData(reinterpret_cast<std::uchar_t const *>(bytes.data()), static_cast<std::int32_t>(bytes.size()), key, nullptr, 95, FONT_DEFAULT, &face.glyphCount);
    BOOST_REQUIRE(face.glyphs != nullptr);
    auto atlas = GenImageFontAtlas(face.glyphs, &face.recs, face.glyphCount, key, 4, 0);
    BOOST_REQUIRE(atlas.data != nullptr);
    for (auto i = std::int32_t{}; i < face.glyphCount; ++i) {
      UnloadImage(face.glyphs[i].image);
      face.glyphs[i].image = ImageFromImage(atlas, face.recs[i]);
    }
    UnloadImage(atlas);
    face.texture.id = 1U;
    fonts_.emplace(key, face);
    return face;
  }
  mutable std::map<std::int32_t, Font> fonts_{};
  std::optional<luma::rect> clip_{};
};

auto preview(vamp_zero::app_state const &state, std::string const &name, vamp_pico::link_status link = vamp_pico::link_status::CONNECTED, std::bool_t busy = false) -> void {
  auto directory = std::filesystem::path{VAMP_TEST_UI_DIR};
  std::filesystem::create_directories(directory);
  auto context = image_context{};
  vamp_zero::draw_header(context, {0.0F, 0.0F, 1024.0F, 600.0F}, state);
  vamp_zero::draw_menu(context, {0.0F, 80.0F, 1024.0F, 520.0F}, state);
  BOOST_REQUIRE(ExportImage(context.image, (directory / ("zero_" + name + ".png")).c_str()));
  auto remote = vamp_pico::remote_display_state{};
  BOOST_REQUIRE(vamp_pico::parse_remote_display_body(vamp_zero::remote_display_text(state), remote));
  auto title = vamp_pico::title_cache{};
  if (remote.title_image[0] != 0) {
    title.select(remote.title_image.data());
    BOOST_REQUIRE(title.accept(remote.title_image.data(), read_bytes(std::filesystem::path{VAMP_TEST_ASSETS_DIR} / "pico/titles" / (std::string{remote.title_image.data()} + ".mask"))));
  }
  auto atlas = read_bytes(directory / "static.p4");
  auto image = GenImageColor(320, 240, WHITE);
  auto row = std::array<std::uint16_t, vamp_pico::display_width>{};
  auto ink = std::size_t{};
  for (auto y = 0U; y < 240U; ++y) {
    vamp_pico::render_scanline(row, y, remote, link, busy, title, atlas);
    for (auto x = 0U; x < 320U; ++x) {
      auto pixel = row[x];
      auto value = Color{static_cast<std::uint8_t>((pixel >> 11U) * 255U / 31U), static_cast<std::uint8_t>(((pixel >> 5U) & 63U) * 255U / 63U), static_cast<std::uint8_t>((pixel & 31U) * 255U / 31U), 255};
      ImageDrawPixel(&image, x, y, value);
      ink += value.r > 128U && value.g > 128U && value.b > 128U ? 1U : 0U;
    }
  }
  BOOST_TEST(ink > 200U);
  BOOST_TEST(ink < 320U * 240U / 2U);
  BOOST_REQUIRE(ExportImage(image, (directory / ("pico_" + name + ".png")).c_str()));
  UnloadImage(image);
}

}

BOOST_AUTO_TEST_CASE(device_menu_rendering_uses_petaluma_and_fits_both_displays) {
  auto state = vamp_zero::app_state{};
  preview(state, "main");
  preview(state, "offline", vamp_pico::link_status::OFFLINE);
  preview(state, "busy", vamp_pico::link_status::CONNECTED, true);
  state.mode = vamp_zero::app_mode::SETTINGS_MENU;
  state.pico_connected = true;
  state.audio.playback_enabled = true;
  state.audio.metronome_enabled = true;
  preview(state, "settings");
  state.selected_settings_index = 3U;
  state.audio.tempo_editing = true;
  preview(state, "tempo");
  state.audio.tempo_editing = false;
  state.mode = vamp_zero::app_mode::PERFORMANCE_SONG_MENU;
  preview(state, "empty");
  auto catalog = std::make_shared<vamp_zero::catalog>();
  auto score = boost::json::parse(read_bytes(std::filesystem::path{VAMP_TEST_ASSETS_DIR} / "songs/autumn_leaves_electric.json"));
  auto title = std::string{score.at("presentation").at("title_image").as_string()};
  catalog->parts.push_back({.id = "electric", .title = "Autumn Leaves", .composer = "Joseph Kosma", .part = "Electric", .total_pages = 32U, .title_image = title});
  catalog->groups.push_back({"Autumn Leaves", "Joseph Kosma", {0U}});
  state.catalog = catalog;
  state.selected_song_index = 1U;
  preview(state, "songs");
  state.mode = vamp_zero::app_mode::PERFORMANCE_PART_MENU;
  state.selected_part_index = 1U;
  preview(state, "parts");
  catalog->groups[0].title = std::string(200U, 'M');
  catalog->groups[0].composer = std::string(200U, 'W');
  preview(state, "long_title");
}