/*
    * navigation.cpp
    * Navigation and file opening logic for the embedded desktop file manager
    * Copyright (c) 2026 Daniel Hammer
*/

#include "filemanager_internal.hpp"

namespace filemanager {

static void filemanager_store_location(FileManagerLocation* location,
                                       const char* path,
                                       FileManagerVirtualViewKind virtual_view) {
    if (!location) return;
    montauk::strncpy(location->path, path ? path : "", sizeof(location->path));
    location->virtual_view = virtual_view;
}

static bool filemanager_location_matches_current(const FileManagerState* fm,
                                                 const FileManagerLocation& location) {
    return fm
        && location.virtual_view == fm->virtual_view
        && montauk::streq(location.path, fm->current_path);
}

static void filemanager_restore_location(FileManagerState* fm, const FileManagerLocation& location) {
    montauk::strncpy(fm->current_path, location.path, sizeof(fm->current_path));

    if (location.virtual_view != FM_VIRTUAL_VIEW_NONE) {
        filemanager_read_virtual_view(fm, location.virtual_view);
    } else if (location.path[0] == '\0') {
        filemanager_read_drives(fm);
    } else {
        filemanager_read_dir(fm);
    }
}

void filemanager_push_history(FileManagerState* fm) {
    if (!fm) return;

    if (fm->history_count > 0 && fm->history_pos >= 0) {
        if (filemanager_location_matches_current(fm, fm->history[fm->history_pos])) return;
    }

    if (fm->history_pos < fm->history_count - 1) {
        fm->history_count = fm->history_pos + 1;
    }

    if (fm->history_count >= 16) {
        for (int i = 1; i < 16; i++) {
            fm->history[i - 1] = fm->history[i];
        }
        fm->history_count = 15;
        fm->history_pos = 14;
    }

    fm->history_pos++;
    filemanager_store_location(&fm->history[fm->history_pos], fm->current_path, fm->virtual_view);
    fm->history_count = fm->history_pos + 1;
}

void filemanager_navigate(FileManagerState* fm, const char* name) {
    int path_len = montauk::slen(fm->current_path);
    if (path_len > 0 && fm->current_path[path_len - 1] != '/') {
        str_append(fm->current_path, "/", 256);
    }
    str_append(fm->current_path, name, 256);
    filemanager_read_dir(fm);
    filemanager_push_history(fm);
}

void filemanager_go_up(FileManagerState* fm) {
    if (filemanager_is_computer_view(fm)) return;

    if (filemanager_is_virtual_view(fm)) {
        filemanager_read_drives(fm);
        filemanager_push_history(fm);
        return;
    }

    int len = montauk::slen(fm->current_path);

    // At drive root (e.g. "0:/" or "10:/") -- go to drives view
    bool is_drive_root = false;
    if (len >= 3 && fm->current_path[len - 1] == '/') {
        int colon = -1;
        for (int i = 0; i < len; i++) {
            if (fm->current_path[i] == ':') { colon = i; break; }
        }
        if (colon >= 0 && colon + 2 == len) is_drive_root = true;
    }
    if (is_drive_root) {
        filemanager_read_drives(fm);
        filemanager_push_history(fm);
        return;
    }

    if (len > 0 && fm->current_path[len - 1] == '/') {
        fm->current_path[len - 1] = '\0';
        len--;
    }

    int last_slash = -1;
    for (int i = len - 1; i >= 0; i--) {
        if (fm->current_path[i] == '/') { last_slash = i; break; }
    }
    if (last_slash >= 0) {
        if (last_slash > 0 && fm->current_path[last_slash - 1] == ':') {
            fm->current_path[last_slash + 1] = '\0';
        } else {
            fm->current_path[last_slash] = '\0';
        }
    }
    filemanager_read_dir(fm);
    filemanager_push_history(fm);
}

void filemanager_navigate_to_history(FileManagerState* fm) {
    if (!fm || fm->history_pos < 0 || fm->history_pos >= fm->history_count) return;
    filemanager_restore_location(fm, fm->history[fm->history_pos]);
}

void filemanager_go_back(FileManagerState* fm) {
    if (fm->history_pos <= 0) return;
    fm->history_pos--;
    filemanager_navigate_to_history(fm);
}

void filemanager_go_forward(FileManagerState* fm) {
    if (fm->history_pos >= fm->history_count - 1) return;
    fm->history_pos++;
    filemanager_navigate_to_history(fm);
}

void filemanager_go_home(FileManagerState* fm) {
    filemanager_read_drives(fm);
    filemanager_push_history(fm);
}

void filemanager_refresh(FileManagerState* fm) {
    if (!fm) return;
    if (filemanager_is_virtual_view(fm)) {
        filemanager_read_virtual_view(fm, fm->virtual_view);
    } else if (filemanager_is_computer_view(fm)) {
        filemanager_read_drives(fm);
    } else {
        filemanager_read_dir(fm);
    }
}

void filemanager_start_pathbar(FileManagerState* fm) {
    fm->pathbar_editing = true;
    if (filemanager_is_computer_view(fm) || filemanager_is_virtual_view(fm)) {
        fm->pathbar_buf[0] = '\0';
        fm->pathbar_len = 0;
    } else {
        montauk::strcpy(fm->pathbar_buf, fm->current_path);
        fm->pathbar_len = montauk::slen(fm->pathbar_buf);
    }
    fm->pathbar_cursor = fm->pathbar_len;
}

void filemanager_cancel_pathbar(FileManagerState* fm) {
    fm->pathbar_editing = false;
}

void filemanager_commit_pathbar(FileManagerState* fm) {
    fm->pathbar_editing = false;
    if (fm->pathbar_len == 0) {
        filemanager_read_drives(fm);
        filemanager_push_history(fm);
        return;
    }
    montauk::strcpy(fm->current_path, fm->pathbar_buf);
    filemanager_read_dir(fm);
    filemanager_push_history(fm);
}

void filemanager_open_entry(FileManagerState* fm, int idx) {
    if (idx < 0 || idx >= fm->entry_count) return;

    if (filemanager_is_computer_view(fm) && fm->entry_types[idx] == FM_ENTRY_SPECIAL_DIR) {
        DesktopState* ds = fm->desktop;
        if (ds && ds->home_dir[0] != '\0') {
            montauk::strcpy(fm->current_path, ds->home_dir);
            int plen = montauk::slen(fm->current_path);
            if (plen > 0 && fm->current_path[plen - 1] != '/')
                str_append(fm->current_path, "/", 256);
            str_append(fm->current_path, fm->entry_names[idx], 256);
            filemanager_read_dir(fm);
            filemanager_push_history(fm);
        }
        return;
    }

    if (filemanager_is_computer_view(fm) && fm->entry_types[idx] == FM_ENTRY_APPS_ROOT) {
        filemanager_read_virtual_view(fm, FM_VIRTUAL_VIEW_APPS);
        filemanager_push_history(fm);
        return;
    }

    if (filemanager_is_computer_view(fm)
        && fm->entry_types[idx] == FM_ENTRY_SYSTEM_CONFIGURATION_ROOT) {
        filemanager_read_virtual_view(fm, FM_VIRTUAL_VIEW_SYSTEM_CONFIGURATION);
        filemanager_push_history(fm);
        return;
    }

    if (filemanager_is_virtual_view(fm) && fm->entry_types[idx] == FM_ENTRY_VIRTUAL_APP) {
        DesktopState* ds = fm->desktop;
        const FileManagerVirtualEntry& entry = fm->virtual_entries[idx];
        if (ds && entry.kind == FM_VIRTUAL_ENTRY_EXTERNAL_APP
            && entry.external_app_index >= 0
            && entry.external_app_index < ds->external_app_count) {
            const ExternalApp& app = ds->external_apps[entry.external_app_index];
            if (app.launch_with_home) {
                montauk::spawn(app.binary_path, ds->home_dir);
            } else {
                montauk::spawn(app.binary_path);
            }
        } else if (ds && entry.kind == FM_VIRTUAL_ENTRY_SYSTEM_CONFIGURATION_APPLET) {
            desktop_launch_system_configuration_applet(ds, &entry.applet);
        }
        return;
    }

    if (filemanager_is_computer_view(fm) && fm->entry_types[idx] == FM_ENTRY_HOME) {
        DesktopState* ds = fm->desktop;
        if (ds && ds->home_dir[0] != '\0') {
            montauk::strcpy(fm->current_path, ds->home_dir);
            filemanager_read_dir(fm);
            filemanager_push_history(fm);
        }
        return;
    }

    if (filemanager_is_computer_view(fm) && fm->entry_types[idx] == FM_ENTRY_DRIVE) {
        int d = fm->drive_indices[idx];
        char dpath[8];
        if (d < 10) {
            dpath[0] = '0' + d; dpath[1] = ':'; dpath[2] = '/'; dpath[3] = '\0';
        } else {
            dpath[0] = '1'; dpath[1] = '0' + (d - 10); dpath[2] = ':'; dpath[3] = '/'; dpath[4] = '\0';
        }
        montauk::strcpy(fm->current_path, dpath);
        filemanager_read_dir(fm);
        filemanager_push_history(fm);
        return;
    }

    if (fm->is_dir[idx]) {
        filemanager_navigate(fm, fm->entry_names[idx]);
        return;
    }

    // Open file with appropriate app
    char fullpath[512];
    filemanager_build_fullpath(fullpath, 512, fm->current_path, fm->entry_names[idx]);
    if (is_image_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/imageviewer/imageviewer.elf", fullpath);
    } else if (is_font_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/fontpreview/fontpreview.elf", fullpath);
    } else if (is_pdf_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/pdfviewer/pdfviewer.elf", fullpath);
    } else if (is_spreadsheet_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/spreadsheet/spreadsheet.elf", fullpath);
    } else if (is_wordprocessor_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/wordprocessor/wordprocessor.elf", fullpath);
    } else if (is_audio_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/music/music.elf", fullpath);
    } else if (is_video_file(fm->entry_names[idx])) {
        montauk::spawn("0:/apps/video/video.elf", fullpath);
    } else if (str_ends_with(fm->entry_names[idx], ".elf")) {
        montauk::spawn(fullpath);
    } else {
        montauk::spawn("0:/apps/texteditor/texteditor.elf", fullpath);
    }
}

} // namespace filemanager