using rjw;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Verse;

namespace RJW_Genes
{
    public static class DiseaseHelper
    {

        /// <summary>
        /// Checks for a pawn if it is immune against a disease.
        /// </summary>
        /// <param name="pawn">The pawn for which immunity is checked</param>
        /// <param name="disease">The genetic disease that is checked against</param>
        /// <returns>True if the pawn is immune, false if the pawn can be infected by it.</returns>
        public static bool IsImmuneAgainstGeneticDisease(Pawn pawn, GeneDef disease)
        {
            // Case 1: Something is null / not working, return Immune (to have less follow up effects)
            if (pawn == null || pawn.genes == null) return true;
            if (disease == null) return true;
            // Case 1.B: Dead people can spread, but not receive, diseases.
            if (pawn.Dead) return true;

            // Case 2A: The pawn has general genetic immunity to diseases
            if (GeneUtility.HasGeneNullCheck(pawn, GeneDefOf.rjw_genes_genetic_disease_immunity))
                return true;

            // Case 2B: The pawn has the carrier gene
            if (GeneUtility.HasGeneNullCheck(pawn, GeneDefOf.rjw_genes_disease_carrier))
                return true;

            // Case 3: The pawn already has the genetic disease
            if (GeneUtility.HasGeneNullCheck(pawn, disease))
                return true;

            // Case 4: Check all genes if one of them has the Immunity Extension that covers the GeneDef
            List<Gene> genes = pawn.genes.GenesListForReading;
            genes = genes.Where(x => pawn.genes.HasActiveGene(x.def)).ToList();

            foreach (Gene gene in genes)
            {
                ImmunityAgainstGenesExtension ext = gene.def.GetModExtension<ImmunityAgainstGenesExtension>();
                if (ext != null) { 
                    foreach (string defname in ext.givesImmunityAgainst)
                        if (disease.defName == defname)
                            return true;
                }
            }

            // Case 5: Nothing special happens, so return false (not immune)
            return false;
        }

        /// <summary>
        /// Returns all active Genes with the `GeneticDiseaseExtension`.
        /// Update v2.3.0: Returns also possible options if the Pawn is a Genetic Disease Carrier.
        /// </summary>
        /// <param name="pawn"></param>
        /// <returns>List of all active Genes with the `GeneticDiseaseExtension` in pawn</returns>
        public static List<GeneDef> GetGeneticDiseaseGenes(Pawn pawn)
        {
            var diseases = new List<GeneDef>() { };
            if (pawn != null && pawn.genes != null)
            {
                diseases = pawn.genes
                    .GenesListForReading
                    .ConvertAll(gene => gene.def)
                    .Where(genedef => pawn.genes.HasActiveGene(genedef))
                    .Where(IsGeneticDiseaseGene)
                    .ToList();
            }

            List<GeneDef> carrierResults = GetGeneticDiseasesGenesFromDiseaseCarrier(pawn);
            diseases.AddRange(carrierResults);

            return diseases;
        }

        public static List<GeneDef> GetGeneticDiseasesGenesFromDiseaseCarrier(Pawn pawn) {
            if (pawn == null) return new List<GeneDef>() { };
            Hediff storage = null;
            pawn.health.hediffSet.TryGetHediff(HediffDefOf.rjw_genes_disease_carrier_storage, out storage);
            if (storage == null) return new List<GeneDef>() { };
            var comp = storage.TryGetComp<HediffComp_DiseaseStorage>();
            if (comp == null) return new List<GeneDef>() { };
            return comp.GetStoredDiseases();
        }

        public static List<GeneDef> GetGeneticInfectorGenes(Pawn pawn)
        {
            if (pawn != null && pawn.genes != null)
            {
                return pawn.genes
                    .GenesListForReading
                    .ConvertAll(gene => gene.def)
                    .Where(genedef => pawn.genes.HasActiveGene(genedef))
                    .Where(IsGeneticInfectorGene)
                    .ToList();
            }

            return new List<GeneDef>() { };
        }

        public static List<GeneDef> LookupInfectionGeneDefs(GeneticInfectorExtension infectorExt)
        {
            if (infectorExt == null) new List<GeneDef>();

            return RimWorld.GeneUtility
                .GenesInOrder
                .Where(genedef => infectorExt.infectionGenes.Contains(genedef.defName))
                .ToList();
        }

        /// <summary>
        /// Checks if the performed sex was penetrative. 
        /// Condom check is not done here!
        /// </summary>
        /// <param name="props">The sexprops </param>
        /// <returns></returns>
        public static bool IsPenetrativeSex(SexProps props)
        {
            if (props == null) return false;

            return props.sexType ==
                xxx.rjwSextype.Vaginal
                || props.sexType == xxx.rjwSextype.Anal
                || props.sexType == xxx.rjwSextype.Oral
                || props.sexType == xxx.rjwSextype.DoublePenetration
                || props.sexType == xxx.rjwSextype.Fellatio
                || props.sexType == xxx.rjwSextype.Sixtynine;
        }

        public static bool IsGeneticDiseaseGene(GeneDef geneDef)
        {
            if (geneDef == null) return false;
            GeneticDiseaseExtension diseaseExt = geneDef.GetModExtension<GeneticDiseaseExtension>();
            return diseaseExt != null;
        }

        public static bool IsGeneticInfectorGene(GeneDef geneDef)
        {
            if (geneDef == null) return false;
            GeneticInfectorExtension infectorExt = geneDef.GetModExtension<GeneticInfectorExtension>();
            return infectorExt != null;
        }

        /// <summary>
        /// Manages storing a genetic disease in a pawn. 
        /// If the pawn is not a carrier, nothing will happen. 
        /// </summary>
        /// <param name="disease">Disease to store</param>
        /// <param name="pawn">Pawn that might be a carrier.</param>
        /// <returns>True if all goes well and disease is stored - false on unapplicable and errors.</returns>
        public static bool TryStoreGeneticDiseaseInCarrier(GeneDef disease, Pawn pawn)
        {
            if (disease == null || pawn == null) return false;

            if (!GeneUtility.HasGeneNullCheck(pawn, GeneDefOf.rjw_genes_disease_carrier))
                return false;
            var store = GetOrCreateDiseaseStorageHediff(pawn).TryGetComp<HediffComp_DiseaseStorage>();
            if (store == null) return false;

            store.StoreDisease(disease);
            ModLog.Debug($"DiseaseCarrier: Stored {disease} in {pawn}");
            return true;
        }


        /// <summary>
        /// Gets (or creates) a Disease Storage Hediff for the `carrier`-pawn, 
        /// </summary>
        /// <param name="inflated"></param>
        /// <returns>A Cumflation Hediff of the inflated pawn.</returns>
        public static Hediff GetOrCreateDiseaseStorageHediff(Pawn carrier)
        {
            Hediff diseaseCarrierHediff = carrier.health.hediffSet.GetFirstHediffOfDef(HediffDefOf.rjw_genes_disease_carrier_storage);
            if (diseaseCarrierHediff == null)
            {
                diseaseCarrierHediff = HediffMaker.MakeHediff(HediffDefOf.rjw_genes_disease_carrier_storage, carrier);
                carrier.health.AddHediff(diseaseCarrierHediff);
            }
            diseaseCarrierHediff.Severity = 1;
            return diseaseCarrierHediff;
        }

        public static float LookupDiseaseInfectionChance(GeneDef geneDef)
        {
            if (IsGeneticDiseaseGene(geneDef))
            {
                GeneticDiseaseExtension diseaseExt = geneDef.GetModExtension<GeneticDiseaseExtension>();
                return diseaseExt != null ? diseaseExt.infectionChance : 0.0f;
            }
            else
                return 0.0f;
        }


    }
}