package org.keycloak.config;

import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;

import com.google.common.base.CaseFormat;

public class Option<T> {
    private final Class<T> type;
    private final Class<?> componentType;
    private final String key;
    private final OptionCategory category;
    private final boolean hidden;
    private final boolean buildTime;
    private final String description;
    private final Optional<T> defaultValue;
    private final List<String> expectedValues;
    private final boolean strictExpectedValues;
    private final boolean caseInsensitiveExpectedValues;
    private final DeprecatedMetadata deprecatedMetadata;
    private final Set<String> connectedOptions;
    private String wildcardKey;

    public Option(Class<T> type, String key, OptionCategory category, boolean hidden, boolean buildTime, String description,
                  Optional<T> defaultValue, List<String> expectedValues, boolean strictExpectedValues, boolean caseInsensitiveExpectedValues,
                  DeprecatedMetadata deprecatedMetadata, Set<String> connectedOptions, String wildcardKey, Class<?> componentType) {
        this.type = type;
        this.key = key;
        this.category = category;
        this.hidden = hidden;
        this.buildTime = buildTime;
        this.description = getDescriptionByCategorySupportLevel(description, category);
        this.defaultValue = defaultValue;
        this.expectedValues = expectedValues;
        this.strictExpectedValues = strictExpectedValues;
        this.caseInsensitiveExpectedValues = caseInsensitiveExpectedValues;
        this.deprecatedMetadata = deprecatedMetadata;
        this.connectedOptions = connectedOptions;
        this.wildcardKey = wildcardKey;
        this.componentType = componentType;
    }

    public Class<T> getType() {
        return type;
    }

    public boolean isHidden() { return hidden; }

    public boolean isBuildTime() {
        return buildTime;
    }

    public String getKey() {
        return key;
    }

    public OptionCategory getCategory() {
        return category;
    }

    public String getDescription() { return description; }

    public Optional<T> getDefaultValue() {
        return defaultValue;
    }

    /**
     * If {@link #isStrictExpectedValues()} is false, custom values can be provided
     * Otherwise, only specified expected values can be used
     *
     * @return expected values
     */
    public List<String> getExpectedValues() {
        return expectedValues;
    }

    /**
     * Denotes whether a custom value can be provided among the expected values
     * If strict, application fails when some custom value is provided
     */
    public boolean isStrictExpectedValues() {
        return strictExpectedValues;
    }

    public boolean isCaseInsensitiveExpectedValues() {
        return caseInsensitiveExpectedValues;
    }

    public Optional<DeprecatedMetadata> getDeprecatedMetadata() {
        return Optional.ofNullable(deprecatedMetadata);
    }

    public Option<T> withRuntimeSpecificDefault(T defaultValue) {
        return toBuilder().defaultValue(defaultValue).build();
    }

    /**
     * Get connected options that have a certain relationship with the current option.
     * Usually when the current option is set, the connected options should be set as well.
     * <br>
     * Not currently meaningful for non-wildcard options
     */
    public Set<String> getConnectedOptions() {
        return connectedOptions; // return the set directly for ease of mutability
    }

    /**
     * Get sibling option name that is able to use a named key - like using wildcards
     * Useful mainly for references in docs
     * f.e. {@code db-username} has wildcard option {@code db-username-<datasource>}
     */
    public Optional<String> getWildcardKey() {
        return Optional.ofNullable(wildcardKey);
    }

    // used for setting the named key implicitly
    void setWildcardKey(String wildcardKey) {
        this.wildcardKey = wildcardKey;
    }

    public OptionBuilder<T> toBuilder() {
        var builder = new OptionBuilder<>(key, type)
                .category(category)
                .buildTime(buildTime)
                .description(description)
                .defaultValue(defaultValue)
                .expectedValues(expectedValues)
                .strictExpectedValues(strictExpectedValues)
                .caseInsensitiveExpectedValues(caseInsensitiveExpectedValues)
                .deprecatedMetadata(deprecatedMetadata)
                .wildcardKey(wildcardKey);

        if (hidden) {
            builder.hidden();
        }
        return builder;
    }

    private static String getDescriptionByCategorySupportLevel(String description, OptionCategory category) {
        if (description != null && !description.isBlank()) {
            switch (category.getSupportLevel()) {
            case PREVIEW:
                description = "Preview: " + description;
                break;
            case EXPERIMENTAL:
                description = "Experimental: " + description;
                break;
            default:
                break;
            }
        }

        return description;
    }

    public static String getDefaultValueString(Object value) {
        if (value == null) {
            return null;
        }
        if (value instanceof List) {
            return ((List<?>) value).stream().map(String::valueOf).collect(Collectors.joining(","));
        }
        return String.valueOf(value);
    }

    /**
     * Transform enum values from upper underscore to lower hyphen
     * Transform enum type HAS_SOMETHING -> has-something
     */
    public static String transformEnumValue(String value) {
        return CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.LOWER_HYPHEN, value);
    }

    public Class<?> getComponentType() {
        return componentType;
    }
}
