#include <imgui/imgui.h>
#include <nativefiledialog-extended/src/include/nfd.h>
#include <optional>

#include "../file.h"
#include "../logcat_entry.h"
#include "export.h"

enum class ExportAmount : int {
    All,
    Filtered,
};

static inline void export_logcat_entries(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers, File& file);
static inline void export_logcat_entries_to_clipboard(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers);
static void export_logcat_entries(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers, auto cb);
static inline std::optional<File> save_file_picker();

void export_fragment(const LogcatEntries& logcat_entries) {
    static ExportAmount export_amount = ExportAmount::Filtered;
    static bool export_buffers = true;

    ImGui::RadioButton("Export all entries", reinterpret_cast<int*>(&export_amount), static_cast<int>(ExportAmount::All));
    ImGui::RadioButton("Export filtered entries", reinterpret_cast<int*>(&export_amount), static_cast<int>(ExportAmount::Filtered));
    ImGui::Checkbox("Export buffers", &export_buffers);
    ImGui::Separator();

    if (ImGui::Button("Export to File")) {
        std::optional<File> file = save_file_picker();
        if (file) {
            ImGui::CloseCurrentPopup();
            try {
                export_logcat_entries(logcat_entries, export_amount, export_buffers, *file);
            } catch (const std::exception& e) {
                log(std::string("Failed to export logcat entries: ") + e.what());
            }
        }
    }

    ImGui::SameLine();
    if (ImGui::Button("Export to Clipboard")) {
        ImGui::CloseCurrentPopup();
        try {
            export_logcat_entries_to_clipboard(logcat_entries, export_amount, export_buffers);
        } catch (const std::exception& e) {
            log(std::string("Failed to export logcat entries: ") + e.what());
        }
    }
}

static inline void export_logcat_entries(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers, File& file) {
    export_logcat_entries(logcat_entries, export_amount, export_buffers, [&](std::string line) {
        file.write(std::move(line));
        file.write("\n", 1);
    });
}

static inline void export_logcat_entries_to_clipboard(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers) {
    std::string text;
    export_logcat_entries(logcat_entries, export_amount, export_buffers, [&](std::string line) {
        text += std::move(line);
        text += '\n';
    });
    ImGui::SetClipboardText(text.c_str());
}

static void export_logcat_entries(const LogcatEntries& logcat_entries, ExportAmount export_amount, bool export_buffers, auto cb) {
    size_t size;
    const LogcatEntry& (LogcatEntries::*get_fn)(size_t) const;
    unsigned int buffers_printed = 0;
    std::optional<Buffer> last_buffer;

    switch (export_amount) {
        case ExportAmount::All:
            size = logcat_entries.size_all();
            get_fn = &LogcatEntries::at_all;
            break;
        case ExportAmount::Filtered:
            size = logcat_entries.size_filtered();
            get_fn = &LogcatEntries::at_filtered;
            break;
    }

    for (size_t i = 0; i < size; i++) {
        const LogcatEntry& entry = (logcat_entries.*get_fn)(i);
        if (export_buffers && (!last_buffer || *last_buffer != entry.buffer)) {
            const char* prefix = buffers_printed & static_cast<unsigned int>(entry.buffer)
                ? "switch to"
                : "beginning of";
            cb(std::string("--------- ") + prefix + ' ' + to_string_lower(entry.buffer));
            buffers_printed |= static_cast<unsigned int>(entry.buffer);
            last_buffer = entry.buffer;
        }

        cb(to_string(entry));
    }
}

static inline std::optional<File> save_file_picker() {
    nfdchar_t* path;
    nfdfilteritem_t filters[1] = {{"Log file", "log"}};
    nfdresult_t res = NFD_SaveDialog(&path, filters, 1, nullptr, "logcat.log");

    if (res == NFD_OKAY) {
        try {
            File file(path, "w");
            NFD_FreePath(path);
            return file;
        } catch (const std::exception& e) {
            NFD_FreePath(path);
            log(std::string("Failed to open file from file picker: ") + e.what());
        }
    } else if (res == NFD_CANCEL) {
        // dialog was canceled, shrug
    } else {
        // ignore error when failing to open the file picker
    }

    return std::nullopt;
}