#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include <limits.h>
#include <string.h>

#include "any_log.h"
#include "config.h"
#include "util.h"

#define ANY_INI_IMPLEMENT
#include "any_ini.h"

typedef enum {
    CONFIG_STRING,
    CONFIG_INT,
    CONFIG_UINT,
    CONFIG_DOUBLE,
    CONFIG_BOOL,
} config_type_t;

typedef struct {
    const char *key;
    config_type_t type;
    size_t offset;
} config_entry_t;

static const config_entry_t config_entries[] = {
    { "width",             CONFIG_UINT,   offsetof(config_t, width) },
    { "height",            CONFIG_UINT,   offsetof(config_t, height) },
    { "font",              CONFIG_STRING, offsetof(config_t, font) },
    { "monitor",           CONFIG_STRING, offsetof(config_t, monitor) },
    { "override_redirect", CONFIG_BOOL,   offsetof(config_t, override_redirect) },
};

static bool config_read_string(const char *value, char **result)
{
    if (value == NULL)
        value = "";

    size_t start = 0, end = strlen(value);
    if (value[0] == '"' && value[end - 1] == '"') {
        start++;
        end--;
    }

    free(*result);
    *result = strslice(value, start, end);
    return true;
}

static bool config_read_int(const char *value, int *result)
{
    char *end;
    long n = strtol(value, &end, 0);
    *result = n;

    if (n > INT_MAX || n < INT_MIN)
        log_debug("Integer %ld is out of range", n);

    return *end == '\0' && n != LONG_MIN && n != LONG_MAX;
}

static bool config_read_uint(const char *value, unsigned int *result)
{
    char *end;
    unsigned long n = strtoul(value, &end, 0);
    *result = n;

    if (n > UINT_MAX)
        log_debug("Integer %lu is out of range", n);

    return *end == '\0' && n != ULONG_MAX;
}

static bool config_read_bool(const char *value, bool *result)
{
    size_t lenght = strlen(value);

    if (lenght == 5 && !strcmp(value, "false")) {
        *result = false;
        return true;
    }

    if (lenght == 4 && !strcmp(value, "true")) {
        *result = true;
        return true;
    }

    log_debug("Invalid bool value");
    return false;
}

static bool config_read_double(const char *value, double *result)
{
    char *end;
    *result = strtod(value, &end);
    return *end == '\0';
}

static bool config_entry(config_t *config, int line, const char *section, const char *key, const char *value)
{
    const int n_entries = sizeof(config_entries) / sizeof(config_entry_t);

    const char *types[] = {
        "string",
        "integer",
        "positive integer",
        "double float",
    };

    for (int i = 0; i < n_entries; i++) {
        if (!strcmp(key, config_entries[i].key)) {
            bool nullable = config_entries[i].type == CONFIG_STRING;

            if ((value == NULL || *value == '\0') && !nullable) {
                log_value_error("Empty config entry",
                                "s:section", section,
                                "s:key", key,
                                "s:expected_type", types[config_entries[i].type],
                                "i:line", line);
                return false;
            }

            void *result = (uint8_t *)config + config_entries[i].offset;
            switch (config_entries[i].type) {
                case CONFIG_STRING:
                    // NOTE: The previous string is freed by config_read_string
                    if (config_read_string(value, (char **)result)) {
                        log_debug("Config '%s' set to '%s'", key, *(char **)result);
                        return true;
                    }
                    break;

                case CONFIG_INT:
                    if (config_read_int(value, (int *)result)) {
                        log_debug("Config '%s' set to '%d'", key, *(int *)result);
                        return true;
                    }
                    break;

                case CONFIG_UINT:
                    if (config_read_uint(value, (unsigned int *)result)) {
                        log_debug("Config '%s' set to '%u'", key, *(unsigned int *)result);
                        return true;
                    }
                    break;

                case CONFIG_DOUBLE:
                    if (config_read_double(value, (double *)result)) {
                        log_debug("Config '%s' set to '%lf'", key, *(double *)result);
                        return true;
                    }
                    break;

                case CONFIG_BOOL:
                    if (config_read_bool(value, (bool *)result)) {
                        log_debug("Config '%s' set to '%s'", key, *(bool *)result ? "true" : "false");
                        return true;
                    }
                    break;

                default:
                    log_panic("Unreachable");
            }

            log_value_error("Invalid config entry",
                            "s:section", section,
                            "s:key", key,
                            "s:value", value,
                            "s:expected_type", types[config_entries[i].type],
                            "i:line", line);

            return false;
        }
    }

    log_value_warn("Unknown config entry",
                   "s:section", section,
                   "s:key", key,
                   "s:value", value,
                   "i:line", line);

    return true;
}

void config_init(config_t *config)
{
    const config_t config_default = {
        .block = {
            .label = "main_block",
            .color = color_rgb(100, 100, 100),
            .type = BLOCK_GROUP,
        },
        .font = "monospace 10",
        .monitor = NULL,
        .height = 50,
        .width = 100,
        .override_redirect = false,
    };

    memcpy(config, &config_default, sizeof(config_t));
    block_copy(&config->block, &config_default.block);

    config->font = strcopy(config_default.font);
    config->monitor = strcopy(config_default.monitor);
}

void config_read(config_t *config, FILE *file)
{
    any_ini_stream_t ini;
    any_ini_file_init(&ini, file);

    int errors = 0;
    char *section = NULL;

    do {
        bool unknown_section = section != NULL && strcmp(section, "bar");

        if (unknown_section)
            log_warn("Unknown section '%s'", section);

        char *key;
        while ((key = any_ini_stream_next_key(&ini)) != NULL) {
            char *value = any_ini_stream_next_value(&ini);

            log_value_trace("Reading config entry",
                            "s:section", section,
                            "s:key", key,
                            "s:value", value,
                            "i:line", ini.line);

            if (!unknown_section)
                errors += !config_entry(config, ini.line, section, key, value);

            free(key);
            free(value);
        }

        free(section);
    } while ((section = any_ini_stream_next_section(&ini)) != NULL);

    if (errors > 0)
        log_panic("Config file contained %d errors", errors);
}

void config_free(config_t *config)
{
    free(config->font);
    free(config->monitor);
    block_free(&config->block);
}