#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>

#include "scheme.h"

#include "../any_log.h"

static void block_ram_update(block_t *block)
{
    FILE *meminfo = fopen("/proc/meminfo", "rb");
    assert(meminfo != NULL);

    uintmax_t total, unused, available, buffers, cached;
    assert(5 == fscanf(meminfo,
                       "MemTotal: %ju kB\n"
                       "MemFree: %ju kB\n"
                       "MemAvailable: %ju kB\n"
                       "Buffers: %ju kB\n"
                       "Cached: %ju kB\n",
                       &total, &unused, &available, &buffers, &cached));
    fclose(meminfo);

    static const char *ram_formats[] = {
        "total",
        "free",
        "used",
        "free-percentage",
        "used-percentage",
        NULL,
    };

    char buffer[32][5] = { 0 };
    snprintf(buffer[0], 32, "%ld", total);
    snprintf(buffer[1], 32, "%ld", available);
    snprintf(buffer[2], 32, "%ld", total - available);
    snprintf(buffer[3], 32, "%ld", 100 * available / total);
    snprintf(buffer[4], 32, "%ld", 100 * (total - available) / total);

    const char *ram_values[] = {
        buffer[0],
        buffer[1],
        buffer[2],
        buffer[3],
        buffer[4],
        NULL,
    };

    free(block->text.text);
    block->text.text = strformat(block->state, '%', ram_formats, ram_values);
    assert(block->text.text != NULL);
}

static void block_ram_finalize(block_t *block)
{
    free(block->state);
}

static bool block_ram_validate(block_t *block, const block_scheme_t *scheme)
{
    if (block->text.text == NULL) {
        log_error("Block '%s' requires key '%s'", block->label, "text");
        return false;
    }

    if (strstr(block->text.text, "%{") == NULL) {
        log_warn("Block '%s' does not use any ram variable", block->label);

        block->update = NULL;
        log_debug("Disabled updates for block '%s'", block->label);
        return true;
    }

    block->state = block->text.text;
    block->text.text = NULL;
    return true;
}

const block_scheme_t block_ram_scheme = {
    .name = "ram",
    .block = {
        .type = BLOCK_TEXT,
        .update_interval = {
            .tv_sec = 1,
            .tv_nsec = 0,
        },
        .update = block_ram_update,
        .finalize = block_ram_finalize,
    },
    .size = sizeof(char *),
    .entries = NULL,
    .validate = block_ram_validate,
};