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

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

static inline void import_logcat_entries(LogcatEntries& logcat_entries, bool ignore_buffer_lines, File& file);
static inline void import_logcat_entries_from_clipboard(LogcatEntries& logcat_entries, bool ignore_buffer_lines);
static void import_logcat_entries(LogcatEntries& logcat_entries, bool ignore_buffer_lines, auto cb);
static inline std::optional<File> open_file_picker();

void import_fragment(LogcatEntries& logcat_entries) {
    static bool ignore_buffer_lines = false;

    ImGui::Checkbox("Ignore buffer lines", &ignore_buffer_lines);

    if (ImGui::Button("Import from File")) {
        std::optional<File> file = open_file_picker();
        if (file) {
            ImGui::CloseCurrentPopup();
            try {
                import_logcat_entries(logcat_entries, ignore_buffer_lines, *file);
            } catch (const std::exception& e) {
                log(std::string("Failed to import logcat entries: ") + e.what());
            }
        }
    }

    ImGui::SameLine();
    if (ImGui::Button("Import from Clipboard")) {
        ImGui::CloseCurrentPopup();
        try {
            import_logcat_entries_from_clipboard(logcat_entries, ignore_buffer_lines);
        } catch (const std::exception& e) {
            log(std::string("Failed to import logcat entries: ") + e.what());
        }
    }
}

static inline void import_logcat_entries(LogcatEntries& logcat_entries, bool ignore_buffer_lines, File& file) {
    auto handle_valid_char = [](char line[MAX_LOGCAT_LINE_SIZE], size_t* line_length, char c) -> std::optional<bool> {
        if (c == '\n') {
            return true;
        }
        if (*line_length == MAX_LOGCAT_LINE_SIZE) {
            throw std::runtime_error("Received line longer than 512k");
        }

        line[*line_length] = c;
        (*line_length)++;

        return std::nullopt;
    };
    auto handle_char = [&](char line[MAX_LOGCAT_LINE_SIZE], size_t* line_length, int c) -> std::optional<bool> {
        if (c != EOF) {
            return handle_valid_char(line, line_length, static_cast<char>(c));
        }

        if (feof(file.get())) {
            return *line_length != 0;
        } else if (ferror(file.get())) {
            throw_system_error("fread()");
        } else {
            throw std::runtime_error("fgetc() returned EOF without setting anything");
        }

        return std::nullopt;
    };

    import_logcat_entries(logcat_entries, ignore_buffer_lines, [&](char line[MAX_LOGCAT_LINE_SIZE], size_t* line_length) {
        *line_length = 0;

        while (true) {
            int c = fgetc(file.get());
            std::optional<bool> ret = handle_char(line, line_length, c);
            if (ret) {
                return *ret;
            }
        }
    });
}

static inline void import_logcat_entries_from_clipboard(LogcatEntries& logcat_entries, bool ignore_buffer_lines) {
    const char* text = ImGui::GetClipboardText();

    import_logcat_entries(logcat_entries, ignore_buffer_lines, [&](char line[MAX_LOGCAT_LINE_SIZE], size_t* line_length) {
        if (!text) {
            return false;
        }

        const char* newline_offset = strchr(text, '\n');
        *line_length = newline_offset ? static_cast<size_t>(newline_offset - text) : strlen(text);

        if (*line_length > MAX_LOGCAT_LINE_SIZE) {
            throw std::runtime_error("Received line longer than 512k");
        }

        memcpy(line, text, *line_length);
        text = newline_offset ? &newline_offset[1] : nullptr;
        return true;
    });
}

static void import_logcat_entries(LogcatEntries& logcat_entries, bool ignore_buffer_lines, auto cb) {
    char line[MAX_LOGCAT_LINE_SIZE];
    size_t line_length;
    Buffer buffer = Buffer::Unknown;

    while (cb(line, &line_length)) {
        if (line_length == 0) {
            continue;
        }

        std::optional<LogcatEntry> logcat_entry = try_parse_logcat_entry(line, line_length, buffer);
        if (logcat_entry) {
            logcat_entries.push_back(std::move(*logcat_entry));
            continue;
        }

        std::optional<Buffer> new_buffer = try_parse_buffer(line, line_length);
        if (new_buffer) {
            if (!ignore_buffer_lines) {
                buffer = *new_buffer;
            }
            continue;
        }

        throw std::invalid_argument(std::string("Cannot parse line: ") + std::string(line, line_length));
    }
}

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

    if (res == NFD_OKAY) {
        try {
            File file(path, "r");
            NFD_FreePath(path);
            return std::move(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;
}