// ============================================================================
// drivers/console/framebuffer.cpp — Framebuffer console driver + device
//
// FramebufferDevice describes the GOP framebuffer hardware (base address,
// resolution, pixel format). FramebufferConsole is the driver that renders
// text to it using a built-in 8x16 VGA bitmap font.
//
// Both are early-allocated (static storage, no heap).
// ============================================================================

#include <kernel/console_driver.h>
#include <kernel/early_driver.h>
#include <kernel/early_device.h>
#include <kernel/platform_bus.h>
#include <boot/boot_info.h>

// ── Minimal 8x16 bitmap font (ASCII 32-126) ──────────────────────────────

static constexpr int FONT_FIRST = 32;
static constexpr int FONT_LAST  = 126;

// clang-format off
static const uint8_t g_font[][16] = {
    // 32: space
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 33: !
    {0x00,0x00,0x18,0x3C,0x3C,0x3C,0x18,0x18,0x18,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
    // 34: "
    {0x00,0x66,0x66,0x66,0x24,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 35: #
    {0x00,0x00,0x00,0x6C,0x6C,0xFE,0x6C,0x6C,0xFE,0x6C,0x6C,0x00,0x00,0x00,0x00,0x00},
    // 36: $
    {0x00,0x10,0x10,0x7C,0xD6,0xD0,0x7C,0x16,0xD6,0x7C,0x10,0x10,0x00,0x00,0x00,0x00},
    // 37: %
    {0x00,0x00,0x00,0x00,0xC2,0xC6,0x0C,0x18,0x30,0x60,0xC6,0x86,0x00,0x00,0x00,0x00},
    // 38: &
    {0x00,0x00,0x38,0x6C,0x6C,0x38,0x76,0xDC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
    // 39: '
    {0x00,0x30,0x30,0x30,0x60,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 40: (
    {0x00,0x00,0x0C,0x18,0x30,0x30,0x30,0x30,0x30,0x30,0x18,0x0C,0x00,0x00,0x00,0x00},
    // 41: )
    {0x00,0x00,0x30,0x18,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x18,0x30,0x00,0x00,0x00,0x00},
    // 42: *
    {0x00,0x00,0x00,0x00,0x00,0x66,0x3C,0xFF,0x3C,0x66,0x00,0x00,0x00,0x00,0x00,0x00},
    // 43: +
    {0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x7E,0x18,0x18,0x00,0x00,0x00,0x00,0x00,0x00},
    // 44: ,
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x18,0x30,0x00,0x00,0x00},
    // 45: -
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 46: .
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
    // 47: /
    {0x00,0x00,0x00,0x00,0x02,0x06,0x0C,0x18,0x30,0x60,0xC0,0x80,0x00,0x00,0x00,0x00},
    // 48-57: 0-9
    {0x00,0x00,0x7C,0xC6,0xC6,0xCE,0xDE,0xF6,0xE6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x18,0x38,0x78,0x18,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0x06,0x0C,0x18,0x30,0x60,0xC0,0xC6,0xFE,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0x06,0x06,0x3C,0x06,0x06,0x06,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x0C,0x1C,0x3C,0x6C,0xCC,0xFE,0x0C,0x0C,0x0C,0x1E,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFE,0xC0,0xC0,0xC0,0xFC,0x06,0x06,0x06,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x38,0x60,0xC0,0xC0,0xFC,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFE,0xC6,0x06,0x06,0x0C,0x18,0x30,0x30,0x30,0x30,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x7C,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x7E,0x06,0x06,0x06,0x0C,0x78,0x00,0x00,0x00,0x00},
    // 58: :
    {0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x00,0x00},
    // 59: ;
    {0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x18,0x18,0x30,0x00,0x00,0x00,0x00},
    // 60: <
    {0x00,0x00,0x00,0x06,0x0C,0x18,0x30,0x60,0x30,0x18,0x0C,0x06,0x00,0x00,0x00,0x00},
    // 61: =
    {0x00,0x00,0x00,0x00,0x00,0x7E,0x00,0x00,0x7E,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 62: >
    {0x00,0x00,0x00,0x60,0x30,0x18,0x0C,0x06,0x0C,0x18,0x30,0x60,0x00,0x00,0x00,0x00},
    // 63: ?
    {0x00,0x00,0x7C,0xC6,0xC6,0x0C,0x18,0x18,0x18,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
    // 64: @
    {0x00,0x00,0x7C,0xC6,0xC6,0xDE,0xDE,0xDE,0xDC,0xC0,0xC0,0x7C,0x00,0x00,0x00,0x00},
    // 65-90: A-Z
    {0x00,0x00,0x10,0x38,0x6C,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x66,0x66,0x66,0x66,0xFC,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x3C,0x66,0xC2,0xC0,0xC0,0xC0,0xC0,0xC2,0x66,0x3C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xF8,0x6C,0x66,0x66,0x66,0x66,0x66,0x66,0x6C,0xF8,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFE,0x66,0x62,0x68,0x78,0x68,0x60,0x62,0x66,0xFE,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFE,0x66,0x62,0x68,0x78,0x68,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x3C,0x66,0xC2,0xC0,0xC0,0xDE,0xC6,0xC6,0x66,0x3A,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x3C,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x1E,0x0C,0x0C,0x0C,0x0C,0x0C,0xCC,0xCC,0xCC,0x78,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xE6,0x66,0x66,0x6C,0x78,0x78,0x6C,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xF0,0x60,0x60,0x60,0x60,0x60,0x60,0x62,0x66,0xFE,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xEE,0xFE,0xFE,0xD6,0xC6,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xE6,0xF6,0xFE,0xDE,0xCE,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x60,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xD6,0xDE,0x7C,0x0C,0x0E,0x00,0x00},
    {0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x6C,0x66,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x7C,0xC6,0xC6,0x60,0x38,0x0C,0x06,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFF,0xDB,0x99,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x10,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xD6,0xD6,0xD6,0xFE,0xEE,0x6C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xC6,0xC6,0x6C,0x7C,0x38,0x38,0x7C,0x6C,0xC6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xCC,0xCC,0xCC,0xCC,0x78,0x30,0x30,0x30,0x30,0x78,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xFE,0xC6,0x86,0x0C,0x18,0x30,0x60,0xC2,0xC6,0xFE,0x00,0x00,0x00,0x00},
    // 91: [
    {0x00,0x00,0x3C,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x3C,0x00,0x00,0x00,0x00},
    // 92: backslash
    {0x00,0x00,0x00,0x80,0xC0,0x60,0x30,0x18,0x0C,0x06,0x02,0x00,0x00,0x00,0x00,0x00},
    // 93: ]
    {0x00,0x00,0x3C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x3C,0x00,0x00,0x00,0x00},
    // 94: ^
    {0x10,0x38,0x6C,0xC6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 95: _
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00},
    // 96: `
    {0x00,0x30,0x18,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
    // 97-122: a-z
    {0x00,0x00,0x00,0x00,0x00,0x78,0x0C,0x7C,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
    {0x00,0x00,0xE0,0x60,0x60,0x78,0x6C,0x66,0x66,0x66,0x66,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xC0,0xC0,0xC0,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x1C,0x0C,0x0C,0x3C,0x6C,0xCC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xFE,0xC0,0xC0,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x38,0x6C,0x64,0x60,0xF0,0x60,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x76,0xCC,0xCC,0xCC,0xCC,0xCC,0x7C,0x0C,0xCC,0x78,0x00},
    {0x00,0x00,0xE0,0x60,0x60,0x6C,0x76,0x66,0x66,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x18,0x18,0x00,0x38,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x06,0x06,0x00,0x0E,0x06,0x06,0x06,0x06,0x06,0x06,0x66,0x66,0x3C,0x00},
    {0x00,0x00,0xE0,0x60,0x60,0x66,0x6C,0x78,0x78,0x6C,0x66,0xE6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x38,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xEC,0xFE,0xD6,0xD6,0xD6,0xD6,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xDC,0x66,0x66,0x66,0x66,0x66,0x66,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xDC,0x66,0x66,0x66,0x66,0x66,0x7C,0x60,0x60,0xF0,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x76,0xCC,0xCC,0xCC,0xCC,0xCC,0x7C,0x0C,0x0C,0x1E,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xDC,0x76,0x66,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0x60,0x38,0x0C,0xC6,0x7C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x10,0x30,0x30,0xFC,0x30,0x30,0x30,0x30,0x36,0x1C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xCC,0xCC,0xCC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xC6,0xC6,0xD6,0xD6,0xD6,0xFE,0x6C,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xC6,0x6C,0x38,0x38,0x38,0x6C,0xC6,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7E,0x06,0x0C,0xF8,0x00},
    {0x00,0x00,0x00,0x00,0x00,0xFE,0xCC,0x18,0x30,0x60,0xC6,0xFE,0x00,0x00,0x00,0x00},
    // 123: {
    {0x00,0x00,0x0E,0x18,0x18,0x18,0x70,0x18,0x18,0x18,0x18,0x0E,0x00,0x00,0x00,0x00},
    // 124: |
    {0x00,0x00,0x18,0x18,0x18,0x18,0x00,0x18,0x18,0x18,0x18,0x18,0x00,0x00,0x00,0x00},
    // 125: }
    {0x00,0x00,0x70,0x18,0x18,0x18,0x0E,0x18,0x18,0x18,0x18,0x70,0x00,0x00,0x00,0x00},
    // 126: ~
    {0x00,0x00,0x76,0xDC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
};
// clang-format on

// ── FramebufferDevice ─────────────────────────────────────────────────────

class FramebufferDevice : public Device, public EarlyDevice<FramebufferDevice> {
public:
    explicit FramebufferDevice(const FramebufferInfo& fb)
        : base_(fb.base), width_(fb.width), height_(fb.height)
        , pitch_(fb.pitch), format_(fb.format)
    {}

    const char* name() const override { return "framebuffer0"; }

    uint64_t    base()   const { return base_; }
    uint32_t    width()  const { return width_; }
    uint32_t    height() const { return height_; }
    uint32_t    pitch()  const { return pitch_; }
    PixelFormat format() const { return format_; }

private:
    uint64_t    base_;
    uint32_t    width_;
    uint32_t    height_;
    uint32_t    pitch_;
    PixelFormat format_;
};

// ── FramebufferConsole driver ─────────────────────────────────────────────

class FramebufferConsole : public ConsoleDriver,
                           public EarlyDriver<FramebufferConsole> {
public:
    FramebufferConsole() = default;

    const char* name() const override { return "framebuffer-console"; }

    bool init() override {
        auto* dev = static_cast<FramebufferDevice*>(device());
        fb_     = reinterpret_cast<uint32_t*>(dev->base());
        width_  = dev->width();
        height_ = dev->height();
        pitch_  = dev->pitch();
        is_bgr_ = (dev->format() == PixelFormat::BGR);
        clear();
        return true;
    }

    void shutdown() override {}

    void putchar(char c) override {
        uint32_t max_cols = width_ / CHAR_W;
        uint32_t max_rows = height_ / CHAR_H;

        if (c == '\n') {
            col_ = 0;
            row_++;
        } else if (c == '\r') {
            col_ = 0;
        } else if (c == '\t') {
            col_ = (col_ + 4) & ~3u;
        } else {
            render_char(col_, row_, c);
            col_++;
        }

        if (col_ >= max_cols) {
            col_ = 0;
            row_++;
        }

        if (row_ >= max_rows) {
            scroll();
            row_ = max_rows - 1;
        }
    }

    void clear() override {
        for (uint32_t y = 0; y < height_; y++) {
            for (uint32_t x = 0; x < width_; x++) {
                put_pixel(x, y, BG_COLOR);
            }
        }
        col_ = 0;
        row_ = 0;
    }

private:
    uint32_t* fb_       = nullptr;
    uint32_t  width_    = 0;
    uint32_t  height_   = 0;
    uint32_t  pitch_    = 0;
    bool      is_bgr_   = false;
    uint32_t  col_      = 0;
    uint32_t  row_      = 0;

    static constexpr uint32_t CHAR_W = 8;
    static constexpr uint32_t CHAR_H = 16;
    static constexpr uint32_t FG_COLOR = CONFIG_FBCON_FG_COLOR;
    static constexpr uint32_t BG_COLOR = CONFIG_FBCON_BG_COLOR;

    void put_pixel(uint32_t x, uint32_t y, uint32_t rgb) {
        if (x >= width_ || y >= height_) return;

        uint32_t color;
        if (is_bgr_) {
            color = ((rgb & 0xFF) << 16) | (rgb & 0xFF00) | ((rgb >> 16) & 0xFF);
        } else {
            color = rgb;
        }

        auto* row = reinterpret_cast<uint32_t*>(
            reinterpret_cast<uint8_t*>(fb_) + y * pitch_);
        row[x] = color;
    }

    void scroll() {
        uint32_t row_bytes = pitch_;
        uint32_t shift = CHAR_H * row_bytes;
        uint32_t total = height_ * row_bytes;

        auto* fb = reinterpret_cast<uint8_t*>(fb_);

        for (uint32_t i = 0; i < total - shift; i++) {
            fb[i] = fb[i + shift];
        }
        for (uint32_t i = total - shift; i < total; i++) {
            fb[i] = 0;
        }
        uint32_t start_y = height_ - CHAR_H;
        for (uint32_t y = start_y; y < height_; y++) {
            for (uint32_t x = 0; x < width_; x++) {
                put_pixel(x, y, BG_COLOR);
            }
        }
    }

    void render_char(uint32_t col, uint32_t row, char c) {
        int idx = static_cast<int>(c) - FONT_FIRST;
        if (idx < 0 || idx > (FONT_LAST - FONT_FIRST)) idx = 0;

        uint32_t px = col * CHAR_W;
        uint32_t py = row * CHAR_H;

        for (uint32_t y = 0; y < CHAR_H; y++) {
            uint8_t bits = g_font[idx][y];
            for (uint32_t x = 0; x < CHAR_W; x++) {
                uint32_t color = (bits & (0x80 >> x)) ? FG_COLOR : BG_COLOR;
                put_pixel(px + x, py + y, color);
            }
        }
    }
};

// ── Driver init function ──────────────────────────────────────────────────

namespace console {

void init_framebuffer(const FramebufferInfo& fb) {
    // Create device on the platform bus
    auto* dev = FramebufferDevice::create(fb);
    platform::bus().add_device(dev);

    // Create driver and bind to device
    auto* drv = FramebufferConsole::create();
    drv->bind(dev);
    drv->init();

    // Register as active console
    console::register_driver(drv);
    console::set_active(drv);
}

} // namespace console