using QuestionsApi.Models;

namespace QuestionsApi.Services;

public static class Step3SystemCatalog
{
    private static readonly IReadOnlyDictionary<string, string> Overrides = new Dictionary<string, string>(StringComparer.Ordinal)
    {
        ["d5-expansion-pediatrics-urea-cycle-hyperammonemia-001"] = "Endocrine System",
        ["d5-expansion-pediatrics-neonatal-hsv-disseminated-001"] = "Immune System, Blood & Lymphoreticular System, and Multisystem Processes/Disorders",
        ["d5-expansion-pediatrics-cdh-delivery-stabilization-001"] = "Respiratory System",
        ["d5-expansion-pediatrics-hie-therapeutic-hypothermia-001"] = "Nervous System & Special Senses",
        ["d5-expansion-pediatrics-fnait-intracranial-bleeding-001"] = "Immune System, Blood & Lymphoreticular System, and Multisystem Processes/Disorders",
        ["nbme6-s3-i029-infant-hyperchloremic-acidosis-growth-risk"] = "Renal/Urinary & Male Reproductive Systems",
        ["form7-s1-i042-genitourinary-syndrome-menopause"] = "Pregnancy/Childbirth & Female Reproductive System & Breast",
        ["free137-i019-inguinal-node-vulvar-source"] = "Pregnancy/Childbirth & Female Reproductive System & Breast",
        ["free137-i061-klinefelter-confirmation"] = "Renal/Urinary & Male Reproductive Systems",
        ["form7-s1-i009-cremasteric-reflex"] = "Renal/Urinary & Male Reproductive Systems",
        ["form7-s2-i015-acrosome-head"] = "Renal/Urinary & Male Reproductive Systems",
        ["nbme6-s1-i033-prostate-primary-osteoblastic-metastases"] = "Renal/Urinary & Male Reproductive Systems",
        ["nbme6-s3-i043-lytic-lesion-hematuria-staging"] = "Renal/Urinary & Male Reproductive Systems"
    };
    public static readonly string[] All =
    [
        "Human Development",
        "Immune System, Blood & Lymphoreticular System, and Multisystem Processes/Disorders",
        "Behavioral Health",
        "Nervous System & Special Senses",
        "Skin & Subcutaneous Tissue",
        "Musculoskeletal System",
        "Cardiovascular System",
        "Respiratory System",
        "Gastrointestinal System",
        "Renal/Urinary & Male Reproductive Systems",
        "Pregnancy/Childbirth & Female Reproductive System & Breast",
        "Endocrine System",
        "Biostatistics & Epidemiology/Population Health & Interpretation of the Medical Literature",
        "Social Sciences: Communication Skills/Ethics/Patient Safety"
    ];

    public static string? Normalize(Question question) =>
        Normalize(question.Step3System)
        ?? Derive(question);

    public static string? Derive(Question question) =>
        Overrides.GetValueOrDefault(question.ExternalId)
        ?? Normalize(question.System) ?? Normalize(question.PerformanceCategory) ?? Normalize(question.Discipline);

    public static string? Normalize(string? value)
    {
        if (string.IsNullOrWhiteSpace(value)) return null;
        var trimmed = value.Trim();
        var exact = All.FirstOrDefault(system => string.Equals(system, trimmed, StringComparison.OrdinalIgnoreCase));
        if (exact is not null) return exact;
        var lower = trimmed.ToLowerInvariant();
        if (Has(lower, "human development", "well patient", "preventive", "health maintenance", "geriatr", "age-related", "neonat")) return All[0];
        if (Has(lower, "social science", "communication", "ethic", "patient safety", "professionalism", "systems-based")) return All[13];
        if (Has(lower, "pregnan", "obstetric", "gynec", "female reproductive", "breast", "puerper")) return All[10];
        if (Has(lower, "renal", "urinary", "male reproductive", "urolog", "nephro")) return All[9];
        if (Has(lower, "biostat", "epidemi", "population health", "medical literature")) return All[12];
        if (Has(lower, "immune", "immun", "blood", "hemat", "lymph", "multisystem", "infectious", "toxicolog", "poisoning", "oncolog", "trauma")) return All[1];
        if (Has(lower, "behavior", "psychi", "mental health")) return All[2];
        if (Has(lower, "nervous", "neuro", "special sense", "ophthalm", "eye & adnexa", "otolaryng", "ear, nose", " ent")) return All[3];
        if (Has(lower, "skin", "derm", "subcutaneous", "integument")) return All[4];
        if (Has(lower, "musculo", "orthop", "rheumat")) return All[5];
        if (Has(lower, "cardio", "circulatory", "peripheral vascular")) return All[6];
        if (Has(lower, "resp", "pulmon")) return All[7];
        if (Has(lower, "gastro", "digest", "hepato", "oral/dental")) return All[8];
        if (Has(lower, "endocr", "metabolic")) return All[11];
        return null;
    }

    private static bool Has(string value, params string[] fragments) => fragments.Any(value.Contains);
}