package org.simantics.scl.compiler.markdown.html;

import java.util.ArrayList;
import java.util.Collections;

import org.simantics.scl.compiler.common.datatypes.Constructor;
import org.simantics.scl.compiler.elaboration.modules.SCLValue;
import org.simantics.scl.compiler.elaboration.modules.TypeClass;
import org.simantics.scl.compiler.elaboration.modules.TypeConstructor;
import org.simantics.scl.compiler.environment.filter.AcceptAllNamespaceFilter;
import org.simantics.scl.compiler.errors.Failable;
import org.simantics.scl.compiler.markdown.internal.ExtensionNodeHandler;
import org.simantics.scl.compiler.markdown.internal.HtmlEscape;
import org.simantics.scl.compiler.markdown.internal.MarkdownParser;
import org.simantics.scl.compiler.markdown.nodes.CodeBlockNode;
import org.simantics.scl.compiler.markdown.nodes.DocumentNode;
import org.simantics.scl.compiler.markdown.nodes.HtmlNode;
import org.simantics.scl.compiler.markdown.nodes.Node;
import org.simantics.scl.compiler.module.Module;
import org.simantics.scl.compiler.module.repository.ModuleRepository;
import org.simantics.scl.compiler.types.TPred;
import org.simantics.scl.compiler.types.TVar;
import org.simantics.scl.compiler.types.Types;
import org.simantics.scl.compiler.types.util.TypeUnparsingContext;

import gnu.trove.map.hash.THashMap;
import gnu.trove.procedure.TObjectProcedure;
import gnu.trove.set.hash.THashSet;

public class SCLDocumentationExtensionNodeHandler implements ExtensionNodeHandler {

    final ModuleRepository moduleRepository;
    final String documentationName;
    
    Failable<Module> relatedModule;
    THashMap<String,Failable<Module>> moduleCache = new THashMap<String,Failable<Module>>(); 
    
    THashSet<String> documentedValues = new THashSet<String>();
    THashSet<String> documentedClasses = new THashSet<String>();
    THashSet<String> documentedTypeConstructors = new THashSet<String>();
    
    public SCLDocumentationExtensionNodeHandler(ModuleRepository moduleRepository,
            String documentationName) {
        this.moduleRepository = moduleRepository;
        this.documentationName = documentationName;
    }

    @Override
    public DocumentNode expandBlock(String extension, String content) {
        if(extension.equals("value")) {
            String[] names = content.split(",");
            DocumentNode container = new DocumentNode();
            for(String name : names) {
                name = name.trim();
                if(name.isEmpty())
                    continue;
                if(!documentedValues.add(name))
                    System.err.println("Value '" + name + "' has already been documented in " + documentationName + ".");
                generateValueDocumentation(container, name);
            }
            return container;
        }
        else if(extension.equals("class")) {
            String[] names = content.split(",");
            DocumentNode container = new DocumentNode();
            for(String name : names) {
                name = name.trim();
                if(name.isEmpty())
                    continue;
                if(!documentedClasses.add(name))
                    System.err.println("Class '" + name + "' has already been documented in " + documentationName + ".");
                generateClassDocumentation(container, name);
            }
            return container;
        }
        else if(extension.equals("data")) {
            String[] names = content.split(",");
            DocumentNode container = new DocumentNode();
            for(String name : names) {
                name = name.trim();
                if(name.isEmpty())
                    continue;
                if(!documentedTypeConstructors.add(name))
                    System.err.println("Type constructor '" + name + "' has already been documented in " + documentationName + ".");
                generateDataDocumentation(container, name);
            }
            return container;
        }
        else if(extension.equals("undocumented")) {
            Module module = getRelatedModule();
            if(module == null)
                return null;
            final ArrayList<String> undocumentedValues = new ArrayList<String>(); 
            module.findValuesForPrefix("", AcceptAllNamespaceFilter.INSTANCE, new TObjectProcedure<SCLValue>() {
                @Override
                public boolean execute(SCLValue value) {
                    if(value.isPrivate())
                        return true;
                    String name = value.getName().name;
                    if(documentedValues.contains(name) ||
                            name.charAt(0) == '_' ||
                            (name.contains("$") && Character.isAlphabetic(name.charAt(0))))
                        return true;
                    undocumentedValues.add(name);
                    return true;
                }
            });
            Collections.sort(undocumentedValues);

            DocumentNode container = new DocumentNode();
            for(String name : undocumentedValues) {
                generateValueDocumentation(container, name);
            }
            return container;
        }
        else
            return null;
    }
    
    private Module getRelatedModule() {
        if(relatedModule == null) {
            relatedModule = moduleRepository.getModule(documentationName);
            if(!relatedModule.didSucceed())
                System.err.println("Couldn't load the module " + documentationName);
        }
        if(relatedModule.didSucceed())
            return relatedModule.getResult();
        else
            return null;
    }
    
    private Module getModule(String moduleName) {
        Failable<Module> fm = moduleCache.get(moduleName);
        if(fm == null) {
            fm = moduleRepository.getModule(moduleName);
            moduleCache.put(moduleName, fm);
            if(!fm.didSucceed())
                System.err.println("Couldn't load the module " + moduleName);
        }
        if(fm.didSucceed())
            return fm.getResult();
        else
            return null;
    }
    
    private void generateValueDocumentation(Node container, String name) {
        int p = name.lastIndexOf('/');
        Module module;
        if(p >= 0) {
            while(p > 0 && name.charAt(p-1) == '/')
                --p;
            module = getModule(name.substring(0, p));
            name = name.substring(p+1);
        }
        else
            module = getRelatedModule();
        
        if(module != null)
            generateValueDocumentation(container, module, name);
    }
    
    private void generateValueDocumentation(Node container, Module module, String name, TypeUnparsingContext tuc) {
        SCLValue value = module.getValue(name);
        if(value == null) {
            StringBuilder error = new StringBuilder();
            error.append("Didn't find the value '" + name + "'.");
            System.err.println(error);
            container.addChild(new CodeBlockNode(error));
            return;
        }
        if(value.isPrivate())
            System.err.println("Documentation " + documentationName + " refers to a private value " + name + ".");
        
        StringBuilder signature = new StringBuilder();
        signature.append("<div id=\"")
        .append(HtmlEscape.escape(name))
        .append("\" class=\"code-doc-box\"><div class=\"code\">");
        char firstChar = name.charAt(0);
        if(!Character.isAlphabetic(firstChar) && firstChar != '_')
            name = "(" + name + ")";
        signature.append(HtmlEscape.escape(name)).append(" :: ");
        String typeStr = Types.removeForAll(value.getType(), new ArrayList<TVar>()).toString(tuc);
        signature.append(HtmlEscape.escape(typeStr));
        String moduleName = module.getName();
        if(!moduleName.equals(documentationName)) {
            signature.append(" <span class=\"greyed\">(").append(moduleName).append(")</span>");
        }
        signature.append("</div><div class=\"doc\">");
        container.addChild(new HtmlNode(signature));
        
        if(value.documentation != null) {
            MarkdownParser parser = new MarkdownParser();
            container.addChild(parser.parseDocument(value.documentation));
        }
        else
            System.out.println(name);
        container.addChild(new HtmlNode("</div></div>"));
    }
    
    private void generateValueDocumentation(Node container, Module module, String name) {
        generateValueDocumentation(container, module, name, new TypeUnparsingContext());
    }
    
    private void generateClassDocumentation(Node container, String name) {
        int p = name.lastIndexOf('/');
        Module module;
        if(p >= 0) {
            module = getModule(name.substring(0, p));
            name = name.substring(p+1);
        }
        else
            module = getRelatedModule();
        
        if(module != null)
            generateClassDocumentation(container, module, name);
    }
    
    private void generateClassDocumentation(Node container, Module module, String name) {
        TypeClass typeClass = module.getTypeClass(name);
        if(typeClass == null) {
            StringBuilder error = new StringBuilder();
            error.append("Didn't find the type class '" + name + "'.");
            System.err.println(error);
            container.addChild(new CodeBlockNode(error));
            return;
        }
        
        TypeUnparsingContext tuc = new TypeUnparsingContext();
        StringBuilder signature = new StringBuilder();
        signature.append("<div class=\"code-doc-box\"><div class=\"code\">");
        signature.append("class ");
        if(typeClass.context.length > 0) {
            signature.append('(');
            boolean first = true;
            for(TPred cx : typeClass.context) {
                if(first)
                    first = false;
                else
                    signature.append(", ");
                cx.toString(tuc, signature);
            }
            signature.append(") => ");
        }
        signature.append(name);
        for(TVar p : typeClass.parameters) {
            signature.append(' ');
            p.toName(tuc, signature);
        } 
        signature.append("</div><div class=\"doc\">");
        container.addChild(new HtmlNode(signature));
        
        if(typeClass.documentation != null) {
            MarkdownParser parser = new MarkdownParser();
            container.addChild(parser.parseDocument(typeClass.documentation));
        }
        else
            System.out.println(name);
        
        for(String methodName : typeClass.methodNames) {
            if(!documentedValues.add(methodName))
                System.err.println("Method '" + methodName + "' has already been documented in " + documentationName + ".");
            generateValueDocumentation(container, module, methodName, new TypeUnparsingContext(tuc));
        }
        container.addChild(new HtmlNode("</div></div>"));
    }

    private void generateDataDocumentation(Node container, String name) {
        int p = name.lastIndexOf('/');
        Module module;
        if(p >= 0) {
            module = getModule(name.substring(0, p));
            name = name.substring(p+1);
        }
        else
            module = getRelatedModule();
        
        if(module != null)
            generateDataDocumentation(container, module, name);
    }
    
    private void generateDataDocumentation(Node container, Module module, String name) {
        TypeConstructor typeConstructor = module.getTypeConstructor(name);
        if(typeConstructor == null) {
            StringBuilder error = new StringBuilder();
            error.append("Didn't find the type constructor '" + name + "'.");
            System.err.println(error);
            container.addChild(new CodeBlockNode(error));
            return;
        }
        
        TypeUnparsingContext tuc = new TypeUnparsingContext();
        StringBuilder signature = new StringBuilder();
        signature.append("<div class=\"code-doc-box\"><div class=\"code\">");
        signature.append("data ");
        signature.append(typeConstructor.name.name);
        for(TVar p : typeConstructor.parameters) {
            signature.append(' ');
            p.toName(tuc, signature);
        }
        String moduleName = module.getName();
        if(!moduleName.equals(documentationName)) {
            signature.append(" <span class=\"greyed\">(").append(moduleName).append(")</span>");
        }
        signature.append("</div><div class=\"doc\">");
        container.addChild(new HtmlNode(signature));
        
        if(typeConstructor.documentation != null) {
            MarkdownParser parser = new MarkdownParser();
            container.addChild(parser.parseDocument(typeConstructor.documentation));
        }
        else
            System.out.println(name);
        
        for(Constructor constructor : typeConstructor.constructors) {
            if(!documentedValues.add(constructor.name.name))
                System.err.println("Method '" + constructor.name.name + "' has already been documented in " + documentationName + ".");
            generateValueDocumentation(container, module, constructor.name.name, new TypeUnparsingContext(tuc));
        }
        container.addChild(new HtmlNode("</div></div>"));
    }
}