/* SPDX-License-Identifier: LGPL-2.1+ */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/input.h>

#include "fd-util.h"
#include "parse-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "udev.h"

static const struct key_name *keyboard_lookup_key(const char *str, GPERF_LEN_TYPE len);
#include "keyboard-keys-from-name.h"

static int install_force_release(struct udev_device *dev, const unsigned *release, unsigned release_count) {
        struct udev_device *atkbd;
        const char *cur;
        char codes[4096];
        char *s;
        size_t l;
        unsigned i;
        int ret;

        assert(dev);
        assert(release);

        atkbd = udev_device_get_parent_with_subsystem_devtype(dev, "serio", NULL);
        if (!atkbd)
                return -ENODEV;

        cur = udev_device_get_sysattr_value(atkbd, "force_release");
        if (!cur)
                return -ENODEV;

        s = codes;
        l = sizeof(codes);

        /* copy current content */
        l = strpcpy(&s, l, cur);

        /* append new codes */
        for (i = 0; i < release_count; i++)
                l = strpcpyf(&s, l, ",%u", release[i]);

        log_debug("keyboard: updating force-release list with '%s'", codes);
        ret = udev_device_set_sysattr_value(atkbd, "force_release", codes);
        if (ret < 0)
                log_error_errno(ret, "Error writing force-release attribute: %m");
        return ret;
}

static void map_keycode(int fd, const char *devnode, int scancode, const char *keycode)
{
        struct {
                unsigned scan;
                unsigned key;
        } map;
        char *endptr;
        const struct key_name *k;
        unsigned keycode_num;

        /* translate identifier to key code */
        k = keyboard_lookup_key(keycode, strlen(keycode));
        if (k) {
                keycode_num = k->id;
        } else {
                /* check if it's a numeric code already */
                keycode_num = strtoul(keycode, &endptr, 0);
                if (endptr[0] !='\0') {
                        log_error("Unknown key identifier '%s'", keycode);
                        return;
                }
        }

        map.scan = scancode;
        map.key = keycode_num;

        log_debug("keyboard: mapping scan code %d (0x%x) to key code %d (0x%x)",
                  map.scan, map.scan, map.key, map.key);

        if (ioctl(fd, EVIOCSKEYCODE, &map) < 0)
                log_error_errno(errno, "Error calling EVIOCSKEYCODE on device node '%s' (scan code 0x%x, key code %d): %m", devnode, map.scan, map.key);
}

static inline char* parse_token(const char *current, int32_t *val_out) {
        char *next;
        int32_t val;

        if (!current)
                return NULL;

        val = strtol(current, &next, 0);
        if (*next && *next != ':')
                return NULL;

        if (next != current)
                *val_out = val;

        if (*next)
                next++;

        return next;
}

static void override_abs(int fd, const char *devnode,
                         unsigned evcode, const char *value) {
        struct input_absinfo absinfo;
        int rc;
        char *next;

        rc = ioctl(fd, EVIOCGABS(evcode), &absinfo);
        if (rc < 0) {
                log_error_errno(errno, "Unable to EVIOCGABS device \"%s\"", devnode);
                return;
        }

        next = parse_token(value, &absinfo.minimum);
        next = parse_token(next, &absinfo.maximum);
        next = parse_token(next, &absinfo.resolution);
        next = parse_token(next, &absinfo.fuzz);
        next = parse_token(next, &absinfo.flat);
        if (!next) {
                log_error("Unable to parse EV_ABS override '%s' for '%s'", value, devnode);
                return;
        }

        log_debug("keyboard: %x overridden with %"PRIi32"/%"PRIi32"/%"PRIi32"/%"PRIi32"/%"PRIi32" for \"%s\"",
                  evcode,
                  absinfo.minimum, absinfo.maximum, absinfo.resolution, absinfo.fuzz, absinfo.flat,
                  devnode);
        rc = ioctl(fd, EVIOCSABS(evcode), &absinfo);
        if (rc < 0)
                log_error_errno(errno, "Unable to EVIOCSABS device \"%s\"", devnode);
}

static void set_trackpoint_sensitivity(struct udev_device *dev, const char *value)
{
        struct udev_device *pdev;
        char val_s[DECIMAL_STR_MAX(int)];
        int r, val_i;

        assert(dev);
        assert(value);

        /* The sensitivity sysfs attr belongs to the serio parent device */
        pdev = udev_device_get_parent_with_subsystem_devtype(dev, "serio", NULL);
        if (!pdev) {
                log_warning("Failed to get serio parent for '%s'", udev_device_get_devnode(dev));
                return;
        }

        r = safe_atoi(value, &val_i);
        if (r < 0) {
                log_error("Unable to parse POINTINGSTICK_SENSITIVITY '%s' for '%s'", value, udev_device_get_devnode(dev));
                return;
        } else if (val_i < 0 || val_i > 255) {
                log_error("POINTINGSTICK_SENSITIVITY %d outside range [0..255] for '%s' ", val_i, udev_device_get_devnode(dev));
                return;
        }

        xsprintf(val_s, "%d", val_i);

        r = udev_device_set_sysattr_value(pdev, "sensitivity", val_s);
        if (r < 0)
                log_error_errno(r, "Failed to write 'sensitivity' attribute for '%s': %m", udev_device_get_devnode(pdev));
}

static int open_device(const char *devnode) {
        int fd;

        fd = open(devnode, O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
        if (fd < 0)
                return log_error_errno(errno, "Error opening device \"%s\": %m", devnode);

        return fd;
}

static int builtin_keyboard(struct udev_device *dev, int argc, char *argv[], bool test) {
        struct udev_list_entry *entry;
        unsigned release[1024];
        unsigned release_count = 0;
        _cleanup_close_ int fd = -1;
        const char *node;
        int has_abs = -1;

        node = udev_device_get_devnode(dev);
        if (!node) {
                log_error("No device node for \"%s\"", udev_device_get_syspath(dev));
                return EXIT_FAILURE;
        }

        udev_list_entry_foreach(entry, udev_device_get_properties_list_entry(dev)) {
                const char *key;
                char *endptr;

                key = udev_list_entry_get_name(entry);
                if (startswith(key, "KEYBOARD_KEY_")) {
                        const char *keycode;
                        unsigned scancode;

                        /* KEYBOARD_KEY_<hex scan code>=<key identifier string> */
                        scancode = strtoul(key + 13, &endptr, 16);
                        if (endptr[0] != '\0') {
                                log_warning("Unable to parse scan code from \"%s\"", key);
                                continue;
                        }

                        keycode = udev_list_entry_get_value(entry);

                        /* a leading '!' needs a force-release entry */
                        if (keycode[0] == '!') {
                                keycode++;

                                release[release_count] = scancode;
                                if (release_count <  ELEMENTSOF(release)-1)
                                        release_count++;

                                if (keycode[0] == '\0')
                                        continue;
                        }

                        if (fd == -1) {
                                fd = open_device(node);
                                if (fd < 0)
                                        return EXIT_FAILURE;
                        }

                        map_keycode(fd, node, scancode, keycode);
                } else if (startswith(key, "EVDEV_ABS_")) {
                        unsigned evcode;

                        /* EVDEV_ABS_<EV_ABS code>=<min>:<max>:<res>:<fuzz>:<flat> */
                        evcode = strtoul(key + 10, &endptr, 16);
                        if (endptr[0] != '\0') {
                                log_warning("Unable to parse EV_ABS code from \"%s\"", key);
                                continue;
                        }

                        if (fd == -1) {
                                fd = open_device(node);
                                if (fd < 0)
                                        return EXIT_FAILURE;
                        }

                        if (has_abs == -1) {
                                unsigned long bits;
                                int rc;

                                rc = ioctl(fd, EVIOCGBIT(0, sizeof(bits)), &bits);
                                if (rc < 0) {
                                        log_error_errno(errno, "Unable to EVIOCGBIT device \"%s\"", node);
                                        return EXIT_FAILURE;
                                }

                                has_abs = !!(bits & (1 << EV_ABS));
                                if (!has_abs)
                                        log_warning("EVDEV_ABS override set but no EV_ABS present on device \"%s\"", node);
                        }

                        if (!has_abs)
                                continue;

                        override_abs(fd, node, evcode, udev_list_entry_get_value(entry));
                } else if (streq(key, "POINTINGSTICK_SENSITIVITY"))
                        set_trackpoint_sensitivity(dev, udev_list_entry_get_value(entry));
        }

        /* install list of force-release codes */
        if (release_count > 0)
                install_force_release(dev, release, release_count);

        return EXIT_SUCCESS;
}

const struct udev_builtin udev_builtin_keyboard = {
        .name = "keyboard",
        .cmd = builtin_keyboard,
        .help = "Keyboard scan code to key mapping",
};
