% | ======================= |
% | == disease data base == |
% | ======================= |

disease('flu',[('pain',['throat']),('runny nose'),('fever',-1),('general weakness'),('cough')],[('pain',['muscles'])]).
disease('malaria',[('fever',2),('general weakness')],[('pain',['head']),('chills'),('erythrocyte',-1)]).
disease('angina',[('fever',2),('cough'),('general weakness'),('magnifying lymph nodes'),('pain',['throat'])],[('cannot swallow'),('pain',['head']),('chills')]).
disease('diphtheria',[('fever',1),('general weakness'),('dyspnea')],[('Unclear Speech'),('cannot swallow')]).
disease('typhoid',[('fever',-1),('pain',['stomach']),('spleen enlargement')],['tire symptoms']).
disease('plague',[('fever',2),('general weakness'),('magnifying lymph nodes'),('liver enlargement'),('spleen enlargement')],[('cloded rash')]).
disease('haemophilia',[('epistaxis'),('impaired blood clotting'),('spleen enlargement')],[]).
disease('whooping cough',[('fever',1),('pain',['throat']),('paroxysmal cough')],[('conjunctivitis'),('vomiting')]).
disease('myasthenia',[('excessive fatigue')],[('muscle weakness'),('double vision')]).
disease('atrial fibrillation',[('dizziness'),('fainting'),('excessive fatigue')],[('cough')]).


% | ===================== |
% | == main procedures == |
% | ===================== |

% temporarily returning true
diagnose(Sentence, Answer) :- true.







% | ==================================== |
% | == disease recognizing procedures == |
% | ==================================== |

% | = auxiliary procedures = |

includesAll(_, []) :- true, !.
includesAll(List, [Inhd|Intl]) :- member(Inhd, List), includesAll(List, Intl), !.

includesAny(_, []) :- false, !.
includesAny(List, [Inhd|Intl]) :- member(Inhd, List); includesAny(List, Intl), !.
    
checkForDiseaseStrong(Symptoms, Disease) :-
    disease(Disease, ObligatorySymptoms, AdditionalSymptoms),
    append(ObligatorySymptoms, AdditionalSymptoms, ExpectedSymptoms),
    includesAll(Symptoms, ObligatorySymptoms),
    includesAll(ExpectedSymptoms, Symptoms),
    !.
    
checkForDiseaseWeak(Symptoms, Disease) :-
    disease(Disease, ObligatorySymptoms, AdditionalSymptoms),
    append(ObligatorySymptoms, AdditionalSymptoms, ExpectedSymptoms),
    includesAny(Symptoms, ExpectedSymptoms),
    includesAll(ExpectedSymptoms, Symptoms),
    !.


% | = suggest procedure = |

% flu
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'flu'),
    Answer = "The patients disease is almost certainly flu.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'flu'),
    Answer = "The patients disease might be flu.".
    
% malaria
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'malaria'),
    Answer = "The patients disease is almost certainly malaria.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'malaria'),
    Answer = "The patients disease might be malaria.".

% angina
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'angina'),
    Answer = "The patients disease is almost certainly angina.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'angina'),
    Answer = "The patients disease might be angina.".
    
% diphtheria
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'diphtheria'),
    Answer = "The patients disease is almost certainly diphtheria.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'diphtheria'),
    Answer = "The patients disease might be diphtheria.".
    
% typhoid
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'typhoid'),
    Answer = "The patients disease is almost certainly typhoid.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'typhoid'),
    Answer = "The patients disease might be typhoid.".
    
% plague
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'plague'),
    Answer = "The patients disease is almost certainly plague.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'plague'),
    Answer = "The patients disease might be plague.".
    
% haemophilia
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'haemophilia'),
    Answer = "The patients disease is almost certainly haemophilia.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'haemophilia'),
    Answer = "The patients disease might be haemophilia.".
    
% whooping cough
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'whooping cough'),
    Answer = "The patients disease is almost certainly whooping cough.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'whooping cough'),
    Answer = "The patients disease might be whooping cough.".
    
% myasthenia
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'myasthenia'),
    Answer = "The patients disease is almost certainly myasthenia.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'myasthenia'),
    Answer = "The patients disease might be myasthenia.".
    
% atrial fibrillation
suggest(Symptoms, Answer) :- 
    checkForDiseaseStrong(Symptoms, 'atrial fibrillation'),
    Answer = "The patients disease is almost certainly atrial fibrillation.".
    
suggest(Symptoms, Answer) :- 
    checkForDiseaseWeak(Symptoms, 'atrial fibrillation'),
    Answer = "The patients disease might be atrial fibrillation.".