#include <pybind11/pybind11.h>
#include <pybind11/stl.h>
#include <pdfengine/pdf_document.hpp>
#include <pdfengine/pdf_engine.hpp>

namespace py = pybind11;

namespace {

void throw_on_error(pdfengine::EngineError err) {
    switch (err) {
        case pdfengine::EngineError::FileNotFound:
            PyErr_SetString(PyExc_FileNotFoundError, "PDF file not found");
            throw py::error_already_set();
        case pdfengine::EngineError::InvalidFormat:
            throw py::value_error("Invalid PDF format");
        case pdfengine::EngineError::PasswordRequired:
            throw py::value_error("Password required to open this PDF");
        case pdfengine::EngineError::InvalidPassword:
            throw py::value_error("Invalid password provided for this PDF");
        case pdfengine::EngineError::PageOutOfBounds:
            throw py::index_error("Page index out of bounds");
        case pdfengine::EngineError::RenderFailed:
            throw std::runtime_error("Failed to render PDF page");
        case pdfengine::EngineError::WriteFailed:
            throw std::runtime_error("Failed to write PDF data");
        default:
            throw std::runtime_error("Unknown PDF engine error");
    }
}

template<typename T>
T get_or_throw(std::expected<T, pdfengine::EngineError>&& res) {
    if (!res.has_value()) {
        throw_on_error(res.error());
    }
    return std::move(res.value());
}

void get_or_throw(std::expected<void, pdfengine::EngineError>&& res) {
    if (!res.has_value()) {
        throw_on_error(res.error());
    }
}

} 

PYBIND11_MODULE(pdfengine, m) {
    m.doc() = "Python bindings for the PdfEngine C++ Core SDK";

    m.def("engine_version", &pdfengine::engineVersion, "Get the engine version string");
    m.def("engine_build_info", &pdfengine::engineBuildInfo, "Get the engine build info string");
    m.def("engine_has_pdfium", &pdfengine::engineHasPdfium, "Check if the engine was built with PDFium support");
    m.def("engine_has_skia", &pdfengine::engineHasSkia, "Check if the engine was built with Skia support");

    py::class_<pdfengine::Point2D>(m, "Point2D")
        .def(py::init<double, double>(), py::arg("x") = 0.0, py::arg("y") = 0.0)
        .def_readwrite("x", &pdfengine::Point2D::x)
        .def_readwrite("y", &pdfengine::Point2D::y)
        .def("__repr__", [](const pdfengine::Point2D& self) {
            return "Point2D(x=" + std::to_string(self.x) + ", y=" + std::to_string(self.y) + ")";
        });

    py::class_<pdfengine::DevicePoint>(m, "DevicePoint")
        .def(py::init<int, int>(), py::arg("x") = 0, py::arg("y") = 0)
        .def_readwrite("x", &pdfengine::DevicePoint::x)
        .def_readwrite("y", &pdfengine::DevicePoint::y)
        .def("__repr__", [](const pdfengine::DevicePoint& self) {
            return "DevicePoint(x=" + std::to_string(self.x) + ", y=" + std::to_string(self.y) + ")";
        });

    py::class_<pdfengine::DocumentMetadata>(m, "DocumentMetadata")
        .def_readonly("title", &pdfengine::DocumentMetadata::title)
        .def_readonly("author", &pdfengine::DocumentMetadata::author)
        .def_readonly("creator", &pdfengine::DocumentMetadata::creator)
        .def_readonly("producer", &pdfengine::DocumentMetadata::producer)
        .def_readonly("creation_date", &pdfengine::DocumentMetadata::creationDate)
        .def_readonly("modification_date", &pdfengine::DocumentMetadata::modificationDate)
        .def("__repr__", [](const pdfengine::DocumentMetadata& self) {
            return "DocumentMetadata(title='" + self.title + "', author='" + self.author + "')";
        });

    py::class_<pdfengine::DocumentPermissions>(m, "DocumentPermissions")
        .def_readonly("is_encrypted", &pdfengine::DocumentPermissions::isEncrypted)
        .def_readonly("encryption", &pdfengine::DocumentPermissions::encryption)
        .def_readonly("security_revision", &pdfengine::DocumentPermissions::securityRevision)
        .def_readonly("owner_unlocked", &pdfengine::DocumentPermissions::ownerUnlocked)
        .def_readonly("can_print", &pdfengine::DocumentPermissions::canPrint)
        .def_readonly("can_print_high_res", &pdfengine::DocumentPermissions::canPrintHighRes)
        .def_readonly("can_modify", &pdfengine::DocumentPermissions::canModify)
        .def_readonly("can_copy", &pdfengine::DocumentPermissions::canCopy)
        .def_readonly("can_annotate", &pdfengine::DocumentPermissions::canAnnotate)
        .def_readonly("can_fill_forms", &pdfengine::DocumentPermissions::canFillForms)
        .def_readonly("can_extract_for_accessibility", &pdfengine::DocumentPermissions::canExtractForAccessibility)
        .def_readonly("can_assemble", &pdfengine::DocumentPermissions::canAssemble);

    py::class_<pdfengine::PageImage>(m, "PageImage")
        .def_readonly("width", &pdfengine::PageImage::width)
        .def_readonly("height", &pdfengine::PageImage::height)
        .def_property_readonly("data", [](const pdfengine::PageImage& self) {
            return py::bytes(reinterpret_cast<const char*>(self.data.data()), self.data.size());
        });

    py::class_<pdfengine::FontInfo>(m, "FontInfo")
        .def_readonly("font_name", &pdfengine::FontInfo::fontName)
        .def_readonly("type", &pdfengine::FontInfo::type)
        .def_readonly("is_embedded", &pdfengine::FontInfo::isEmbedded)
        .def_readonly("is_subset", &pdfengine::FontInfo::isSubset)
        .def_readonly("is_vertical", &pdfengine::FontInfo::isVertical)
        .def_readonly("encoding", &pdfengine::FontInfo::encoding)
        .def_readonly("has_to_unicode", &pdfengine::FontInfo::hasToUnicode)
        .def_readonly("cmap_name", &pdfengine::FontInfo::cmapName)
        .def_readonly("cid_system_info", &pdfengine::FontInfo::cidSystemInfo)
        .def_readonly("subset_tag", &pdfengine::FontInfo::subsetTag)
        .def_readonly("source_type", &pdfengine::FontInfo::sourceType)
        .def_readonly("substituted_from", &pdfengine::FontInfo::substitutedFrom)
        .def_readonly("substituted_to", &pdfengine::FontInfo::substitutedTo)
        .def_readonly("normalized_family", &pdfengine::FontInfo::normalizedFamily)
        .def_readonly("internal_font_id", &pdfengine::FontInfo::internalFontId)
        .def_readonly("flags", &pdfengine::FontInfo::flags)
        .def_readonly("ascent", &pdfengine::FontInfo::ascent)
        .def_readonly("descent", &pdfengine::FontInfo::descent)
        .def_readonly("cap_height", &pdfengine::FontInfo::capHeight)
        .def("__repr__", [](const pdfengine::FontInfo& self) {
            return "FontInfo(font_name='" + self.fontName + "', type='" + self.type + "', is_embedded=" + (self.isEmbedded ? "True" : "False") + ")";
        });

    py::class_<pdfengine::Glyph>(m, "Glyph")
        .def_readonly("text", &pdfengine::Glyph::text)
        .def_readonly("unicode", &pdfengine::Glyph::unicode)
        .def_readonly("font_name", &pdfengine::Glyph::fontName)
        .def_readonly("flags", &pdfengine::Glyph::flags)
        .def_readonly("font_size", &pdfengine::Glyph::fontSize)
        .def_readonly("origin_x", &pdfengine::Glyph::originX)
        .def_readonly("origin_y", &pdfengine::Glyph::originY)
        .def_readonly("bbox_x", &pdfengine::Glyph::bboxX)
        .def_readonly("bbox_y", &pdfengine::Glyph::bboxY)
        .def_readonly("bbox_w", &pdfengine::Glyph::bboxW)
        .def_readonly("bbox_h", &pdfengine::Glyph::bboxH)
        .def_readonly("angle", &pdfengine::Glyph::angle)
        .def_readonly("page_object_index", &pdfengine::Glyph::pageObjectIndex);

    py::class_<pdfengine::TextRun>(m, "TextRun")
        .def_readonly("text", &pdfengine::TextRun::text)
        .def_readonly("font_name", &pdfengine::TextRun::fontName)
        .def_readonly("flags", &pdfengine::TextRun::flags)
        .def_readonly("font_size", &pdfengine::TextRun::fontSize)
        .def_readonly("internal_font_id", &pdfengine::TextRun::internalFontId)
        .def_readonly("is_embedded", &pdfengine::TextRun::isEmbedded)
        .def_readonly("type", &pdfengine::TextRun::type)
        .def_readonly("glyphs", &pdfengine::TextRun::glyphs)
        .def_readonly("x", &pdfengine::TextRun::x)
        .def_readonly("y", &pdfengine::TextRun::y)
        .def_readonly("w", &pdfengine::TextRun::w)
        .def_readonly("h", &pdfengine::TextRun::h)
        .def_readonly("object_indices", &pdfengine::TextRun::objectIndices)
        .def_readonly("fill_color", &pdfengine::TextRun::fillColor);

    py::class_<pdfengine::TextLine>(m, "TextLine")
        .def_readonly("runs", &pdfengine::TextLine::runs)
        .def_readonly("baseline_y", &pdfengine::TextLine::baselineY)
        .def_readonly("x", &pdfengine::TextLine::x)
        .def_readonly("y", &pdfengine::TextLine::y)
        .def_readonly("w", &pdfengine::TextLine::w)
        .def_readonly("h", &pdfengine::TextLine::h);

    py::class_<pdfengine::Paragraph>(m, "Paragraph")
        .def_readonly("lines", &pdfengine::Paragraph::lines)
        .def_readonly("x", &pdfengine::Paragraph::x)
        .def_readonly("y", &pdfengine::Paragraph::y)
        .def_readonly("w", &pdfengine::Paragraph::w)
        .def_readonly("h", &pdfengine::Paragraph::h);

    py::class_<pdfengine::PageModel>(m, "PageModel")
        .def_readonly("paragraphs", &pdfengine::PageModel::paragraphs)
        .def_readonly("width", &pdfengine::PageModel::width)
        .def_readonly("height", &pdfengine::PageModel::height)
        .def_readonly("page_index", &pdfengine::PageModel::pageIndex);

    py::class_<pdfengine::PdfPage::AnnotationInfo>(m, "AnnotationInfo")
        .def_readonly("id", &pdfengine::PdfPage::AnnotationInfo::id)
        .def_readonly("type", &pdfengine::PdfPage::AnnotationInfo::type)
        .def_readonly("x", &pdfengine::PdfPage::AnnotationInfo::x)
        .def_readonly("y", &pdfengine::PdfPage::AnnotationInfo::y)
        .def_readonly("width", &pdfengine::PdfPage::AnnotationInfo::width)
        .def_readonly("height", &pdfengine::PdfPage::AnnotationInfo::height)
        .def_readonly("color", &pdfengine::PdfPage::AnnotationInfo::color)
        .def_readonly("author", &pdfengine::PdfPage::AnnotationInfo::author)
        .def_readonly("content", &pdfengine::PdfPage::AnnotationInfo::content)
        .def_readonly("timestamp", &pdfengine::PdfPage::AnnotationInfo::timestamp)
        .def_readonly("page_index", &pdfengine::PdfPage::AnnotationInfo::pageIndex)
        .def_readonly("paths", &pdfengine::PdfPage::AnnotationInfo::paths)
        .def_readonly("field_name", &pdfengine::PdfPage::AnnotationInfo::fieldName)
        .def_readonly("field_value", &pdfengine::PdfPage::AnnotationInfo::fieldValue)
        .def_readonly("field_type", &pdfengine::PdfPage::AnnotationInfo::fieldType)
        .def_readonly("field_flags", &pdfengine::PdfPage::AnnotationInfo::fieldFlags)
        .def_readonly("field_options", &pdfengine::PdfPage::AnnotationInfo::fieldOptions);

    py::class_<pdfengine::PdfPage, std::shared_ptr<pdfengine::PdfPage>>(m, "PdfPage")
        .def_property_readonly("width", &pdfengine::PdfPage::width)
        .def_property_readonly("height", &pdfengine::PdfPage::height)
        .def("render", [](const pdfengine::PdfPage& self, int dpi) {
            return get_or_throw(self.render(dpi));
        }, py::arg("dpi") = 96)
        .def("extract_document_model", [](const pdfengine::PdfPage& self) {
            return get_or_throw(self.extractDocumentModel());
        })
        .def("extract_text", [](const pdfengine::PdfPage& self) {
            return get_or_throw(self.extractText());
        })
        .def("extract_annotations_text", [](const pdfengine::PdfPage& self) {
            return get_or_throw(self.extractAnnotationsText());
        })
        .def("extract_annotations", [](const pdfengine::PdfPage& self) {
            return get_or_throw(self.extractAnnotations());
        })
        .def("extract_text_with_bounds", [](const pdfengine::PdfPage& self) {
            auto res = get_or_throw(self.extractTextWithBounds());
            py::list py_list;
            for (const auto& glyph : res) {
                py::dict d;
                d["text"] = glyph.text;
                d["x"] = glyph.x;
                d["y"] = glyph.y;
                d["w"] = glyph.w;
                d["h"] = glyph.h;
                d["fontSize"] = glyph.fontSize;
                py_list.append(d);
            }
            return py_list;
        })
        .def("ordered_glyphs", [](const pdfengine::PdfPage& self) {
            auto res = get_or_throw(self.orderedGlyphs());
            py::list py_list;
            for (const auto& g : res) {
                py::dict d;
                d["text"] = g.text; d["x"] = g.x; d["y"] = g.y;
                d["w"] = g.w; d["h"] = g.h; d["fontSize"] = g.fontSize;
                py_list.append(d);
            }
            return py_list;
        })
        .def("hit_glyph", [](const pdfengine::PdfPage& self, double x, double y) {
            auto hit = get_or_throw(self.hitGlyph(x, y));
            py::dict d;
            d["glyphIndex"] = hit.glyphIndex;
            d["caret"] = hit.caret;
            d["line"] = hit.line;
            return d;
        }, py::arg("x"), py::arg("y"))
        .def("select_range", [](const pdfengine::PdfPage& self, double ax, double ay, double bx, double by) {
            auto sel = get_or_throw(self.selectRange(ax, ay, bx, by));
            py::dict d;
            d["startGlyph"] = sel.startGlyph;
            d["endGlyph"] = sel.endGlyph;
            d["text"] = sel.text;
            py::list rects;
            for (const auto& r : sel.rects) {
                py::dict rd;
                rd["x"] = r.x; rd["y"] = r.y; rd["w"] = r.w; rd["h"] = r.h;
                rects.append(rd);
            }
            d["rects"] = rects;
            return d;
        }, py::arg("ax"), py::arg("ay"), py::arg("bx"), py::arg("by"))
        .def("get_fonts", [](const pdfengine::PdfPage& self) {
            return get_or_throw(self.getFonts());
        })
        .def("get_glyph_width", [](const pdfengine::PdfPage& self, const std::string& fontName, uint32_t charcode, double fontSize) {
            return get_or_throw(self.getGlyphWidth(fontName, charcode, fontSize));
        }, py::arg("font_name"), py::arg("charcode"), py::arg("font_size"))
        .def("page_to_device", &pdfengine::PdfPage::pageToDevice, 
             py::arg("page_point"), py::arg("device_width"), py::arg("device_height"), py::arg("rotate") = 0)
        .def("device_to_page", &pdfengine::PdfPage::deviceToPage, 
             py::arg("device_point"), py::arg("device_width"), py::arg("device_height"), py::arg("rotate") = 0);

    py::class_<pdfengine::PdfDocument, std::shared_ptr<pdfengine::PdfDocument>>(m, "PdfDocument")
        .def_static("load_from_file", [](const std::string& path, const std::string& password) {
            return get_or_throw(pdfengine::PdfDocument::loadFromFile(path, password));
        }, py::arg("path"), py::arg("password") = "")
        .def_static("load_from_memory", [](const py::bytes& bytes, const std::string& password) {
            std::string_view sv = bytes;
            std::vector<uint8_t> data(sv.begin(), sv.end());
            return get_or_throw(pdfengine::PdfDocument::loadFromMemory(data, password));
        }, py::arg("data"), py::arg("password") = "")
        .def_property_readonly("page_count", &pdfengine::PdfDocument::pageCount)
        .def_property_readonly("metadata", &pdfengine::PdfDocument::metadata)
        .def_property_readonly("permissions", &pdfengine::PdfDocument::permissions)
        .def("extract_outline", [](const pdfengine::PdfDocument& self) {
            auto res = get_or_throw(self.extractOutline());
            py::list out;
            for (const auto& item : res) {
                py::dict d;
                d["title"] = item.title;
                d["pageIndex"] = item.pageIndex;
                d["level"] = item.level;
                out.append(d);
            }
            return out;
        })
        .def("get_page", [](pdfengine::PdfDocument& self, int pageIndex) {
            return get_or_throw(self.getPage(pageIndex));
        }, py::arg("page_index"))
        .def("get_fonts", [](const pdfengine::PdfDocument& self, int start_page, int end_page) {
            return get_or_throw(self.getFonts(start_page, end_page));
        }, py::arg("start_page") = 0, py::arg("end_page") = -1)
        .def("get_font_data", [](const pdfengine::PdfDocument& self, const std::string& internal_font_id) {
            // Raw embedded font bytes for the given run font; empty bytes when the font
            // is not embedded / not found (the gateway maps that to a 404 + CSS fallback).
            auto res = self.getFontData(internal_font_id);
            if (!res || res->empty()) {
                return py::bytes();
            }
            return py::bytes(reinterpret_cast<const char*>(res->data()), res->size());
        }, py::arg("internal_font_id"))
        .def("apply_edits", [](pdfengine::PdfDocument& self, const std::string& editsJson) {
            get_or_throw(self.applyEdits(editsJson));
        }, py::arg("edits_json"))
        .def("save_incremental", [](const pdfengine::PdfDocument& self) {
            std::vector<uint8_t> res = get_or_throw(self.saveIncremental());
            return py::bytes(reinterpret_cast<const char*>(res.data()), res.size());
        })
        .def("save_full", [](const pdfengine::PdfDocument& self) {
            std::vector<uint8_t> res = get_or_throw(self.saveFull());
            return py::bytes(reinterpret_cast<const char*>(res.data()), res.size());
        });
}