#include <drivers/ports.h>
#include <drivers/vgascreen.h>
#include <libc/libc.h>
#include <cpu/isr.h>
#include <cpu/timer.h>
#include <drivers/keyboard.h>
#include <mem/mem.h>
#include <multiboot.h>
#include <drivers/serial.h>
#include <kprint.h>
#include <libc/readline.h>
#include <libc/string.h>
#include <libk.h>
#include <drivers/pci.h>
#include <drivers/ide.h>
#include <libc/kprintf.h>
#include <fs/mbr.h>
#include <fs/blockdev.h>
#include <fs/fat.h>
#include <stdbool.h>

#define BOOTLOADER_NAME_MAX_LENGTH 64
#define CMDLINE_MAX_LENGTH 256

const int version_major = 0,
        version_minor = 0,
        version_patch = 1;

char bootloader_name[BOOTLOADER_NAME_MAX_LENGTH];
char cmdline[CMDLINE_MAX_LENGTH];

typedef void (*cmd_handler_func)(const char *);

typedef struct {
    char *cmd;
    cmd_handler_func handler;
} cmd_handler;

void print(const char *arg);

void ide(const char *arg);

void echo(const char *arg);

void help(const char *arg);

cmd_handler cmd_handlers[] = {
        {"help",  help},
        {"echo",  echo},
        {"print", print},
        {"ide",   ide},
        {NULL, NULL},
};

void print_bootinfo() {
    printf("Bootloader name: %s\n"
           "cmdline: %s\n",
           (bootloader_name[0] == 0 ? "NULL" : bootloader_name),
           (cmdline[0] == 0 ? "NULL" : cmdline));
}

void help(const char *arg) {
    kprint("Available commands:\n");
    int index = 0;
    while (true) {
        if (cmd_handlers[index].cmd == NULL) {
            break;
        }
        printf("%s\n", cmd_handlers[index].cmd);
        index += 1;
    }

}

void echo(const char *arg) {
    printf("%s\n", arg);
}

void print(const char *arg) {
    if (strcmp(arg, "mmap") == 0) {
        print_mmap_info();
    } else if (strcmp(arg, "malloc") == 0) {
        print_malloc_info();
    } else if (strcmp(arg, "tick") == 0) {
        print_current_tick();
    } else if (strcmp(arg, "bootinfo") == 0) {
        print_bootinfo();
    } else if (strcmp(arg, "pci") == 0) {
        pci_print_info();
    } else if (strcmp(arg, "ide") == 0) {
        ide_print_devices();
    } else {
        printf("Unknown print %s\n", arg);
    }
}

void ide(const char *arg) {
    if (strcmp(arg, "block_devices") == 0) {
        block_dev_print_info();
    } else if (strcmp(arg, "ide_devices") == 0) {
        ide_print_devices();
    } else if (strcmp(arg, "mbr") == 0) {
        mbr_read_from_ide(0);
    } else {
        printf("Unknown print %s\n", arg);
    }
}

void main_loop();

void store_bootloader_info(multiboot_info_t *multiboot_info) {
    // get bootloader and cmdline
    if (multiboot_info->flags & MULTIBOOT_INFO_CMDLINE) {
        int cmdline_length = strlen((const char *) multiboot_info->cmdline);
        if (cmdline_length > CMDLINE_MAX_LENGTH) {
            k_panics("cmdline to long!\n");
        }
        memcpy(cmdline, (char *) multiboot_info->cmdline, cmdline_length);
    }
    if (multiboot_info->flags & MULTIBOOT_INFO_BOOT_LOADER_NAME) {
        int bootloader_length = strlen((const char *) multiboot_info->boot_loader_name);
        if (bootloader_length > BOOTLOADER_NAME_MAX_LENGTH) {
            k_panics("bootloader name to long!\n");
        }
        memcpy(bootloader_name, (char *) multiboot_info->boot_loader_name, bootloader_length);
    }
}

void init_mmap(multiboot_info_t *multiboot_info) {
    if (multiboot_info->flags & (1 << 6)) {
        init_mmap_multiboot((struct multiboot_mmap_entry *) multiboot_info->mmap_addr,
                            multiboot_info->mmap_length / sizeof(struct multiboot_mmap_entry));
        // todo fallback on other mechanisms?
    } else {
        k_panics("mmap invalid!\n");
    }
}

void register_pci_drivers() {
    ide_register();
}

void init_pci_system() {
    register_pci_drivers();
    pci_sort_drivers();
    pci_scan();
    pci_init_drivers();
}

void init_block_devices() {
    // register drivers
    mbr_register_block_driver();
    fat_register_block_driver();

    // scan
    block_dev_scan_repeat();
}

void kmain(multiboot_info_t *multiboot_info) {
    isr_install();
    vga_clear_screen();
    vga_clear_screen(' ', VGA_WHITE | (VGA_GRAY << VGA_SHIFT_BG));
    kprint_register(vga_kprint);
    serial_init();
    kprint_register(serial_kprint);

    store_bootloader_info(multiboot_info);
    init_mmap(multiboot_info);

    // init done, enable interrupts
    __asm__ __volatile__("sti");
    init_timer(1000);
    init_keyboard();
    init_pci_system();
    init_block_devices();

    printf("Booted successfully v%d.%d.%d\n", version_major, version_minor, version_patch);

    // enter main loop
    while (true) {
        main_loop();
    }
}

void main_loop() {
    char *msg = readline(NULL);
    char *args = strchr(msg, ' ') + 1;
    args[-1] = 0;
    int test_index = 0;
    while (true) {
        if (cmd_handlers[test_index].cmd == 0) {
            printf("Unknown command: %s\n", msg);
            break;
        }
        if (strcmp(cmd_handlers[test_index].cmd, msg) == 0) {
            cmd_handlers[test_index].handler(args);
            break;
        }
        test_index++;
    }
    free(msg);
}