buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.squareup:javapoet:1.8.0'
    }
}

import com.squareup.javapoet.*
import javafx.util.Pair

import javax.lang.model.element.Modifier

abstract class SchemeObject {

    List<String> lines = new ArrayList<>();

    abstract void writeToFile(File directory, Map<String, SchemeObject> objects)

    abstract void readLine(String line, Map<String, SchemeObject> objects)

}
//TODO: constructor
//TODO: YAML
//TODO: datetime
//TODO: missable in future
//TODO: register all maps/collections classes and work with java typical types
class ImportObject extends SchemeObject {

    static final String SIGNATURE = "import"

    final String name
    final String fullName

    ImportObject(String firstLine) {
        fullName = firstLine.substring(SIGNATURE.length()).trim()
        name = fullName.substring(fullName.lastIndexOf('.') + 1)
    }

    @Override
    void writeToFile(final File directory, Map<String, SchemeObject> objects) {
        //do nothing - imports are for other objects
    }

    @Override
    void readLine(final String line, Map<String, SchemeObject> objects) {
        throw new Exception("Line is not related to import: '" + line + "'")
    }

}

class EnumObject extends SchemeObject {

    enum Type {
        STRING, NUMBER, BOOLEAN
    }

    static final String SIGNATURE = "enum"

    final String name
    Type type

    Map<String, Object> values = new HashMap<>()

    EnumObject(String firstLine) {
        name = firstLine.substring(SIGNATURE.length()).trim()
    }

    @Override
    void writeToFile(File directory, Map<String, SchemeObject> objects) {
        TypeSpec.Builder enumBuilder = TypeSpec.enumBuilder(name)
                .addModifiers(Modifier.PUBLIC)
                .addSuperinterface(ClassName.bestGuess("ru.touchin.templates.logansquare.LoganSquareEnum"))

        enumBuilder.addField(FieldSpec.builder(ClassName.get(String.class), "valueName",
                Modifier.PRIVATE,
                Modifier.FINAL)
                .addAnnotation(ClassName.bestGuess("android.support.annotation.NonNull"))
                .build())

        enumBuilder.addMethod(MethodSpec.constructorBuilder()
                .addParameter(ClassName.get(String.class), "valueName", Modifier.FINAL)
                .addStatement("this.valueName = valueName")
                .build())

        enumBuilder.addMethod(MethodSpec.methodBuilder("getValueName")
                .returns(ClassName.get(String.class))
                .addModifiers(Modifier.PUBLIC)
                .addAnnotation(ClassName.get(Override.class))
                .addAnnotation(ClassName.bestGuess("android.support.annotation.NonNull"))
                .addStatement("return valueName")
                .build())

        enumBuilder.addType(TypeSpec.classBuilder("LoganSquareConverter")
                .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
                .superclass(ParameterizedTypeName.get(ClassName.bestGuess("ru.touchin.templates.logansquare.LoganSquareEnumConverter"), ClassName.bestGuess(name)))
                .addMethod(MethodSpec.constructorBuilder()
                .addModifiers(Modifier.PUBLIC)
                .addStatement("super(values())")
                .build())
                .build())

        for (Map.Entry<String, Object> entry : values) {
            if (type == Type.STRING) {
                enumBuilder.addEnumConstant(entry.key, TypeSpec.anonymousClassBuilder("\$S", entry.value).build())
            } else {
                enumBuilder.addEnumConstant(entry.key, TypeSpec.anonymousClassBuilder("\$L", entry.value).build())
            }
        }

        JavaFile.builder("com.touchin.sberinkas", enumBuilder.build()).indent("    ").build().writeTo(directory);
    }

    Type typeOf(String value) {
        if (value.equals("true") || value.equals("false")) {
            return Type.BOOLEAN
        } else {
            try {
                Integer.parseInt(value)
                return Type.NUMBER
            } catch (NumberFormatException ignored) {
                return Type.STRING
            }
        }
    }

    @Override
    void readLine(final String line, Map<String, SchemeObject> objects) {
        String[] parts = line.split(':')
        String name = parts[0].trim();
        if (name.isEmpty()) {
            throw new Exception("Name of enum is empty")
        }
        if (values.containsKey(name)) {
            throw new Exception("Name '" + value + "' already added to enum")
        }
        String value = parts[1].trim();
        Type type = typeOf(value)
        if (this.type == null) {
            this.type = type
        } else if (this.type != type) {
            throw new Exception("Type of value '" + value + "' conflicts with previous value type: " + this.type)
        }
        values.put(name, value)
    }

}

enum FieldType {

    BOOLEAN(TypeName.BOOLEAN), INT(TypeName.INT), LONG(TypeName.LONG), FLOAT(TypeName.FLOAT),
    STRING(ClassName.get(String.class)), ARRAY(ClassName.get(List.class)), MAP(ClassName.get(Map.class)),
    ENUM(null), MODEL(null), IMPORTED_MODEL(null), GENERIC(null)

    final TypeName typeName

    FieldType(final TypeName typeName) {
        this.typeName = typeName
    }

    static FieldType get(String typeString, Map<String, SchemeObject> objects) {
        switch (typeString) {
            case "string": return STRING
            case "array": return ARRAY
            case "map": return MAP
            case "int": return INT
            case "boolean": return BOOLEAN
            case "long": return LONG
            case "float": return FLOAT
            default:
                SchemeObject object = objects.get(typeString);
                if (object instanceof EnumObject) {
                    return ENUM
                }
                if (object instanceof ImportObject) {
                    return IMPORTED_MODEL
                }
                if (object instanceof ClassObject) {
                    return MODEL
                }
                return GENERIC
        }
    }

}

class TypeNameUtils {

    static TypeName resolveType(String string, Map<String, SchemeObject> objects) {
        String argumentName = FieldInfo.getTypeSimpleName(string)
        SchemeObject schemeObject = objects.get(argumentName)
        if (schemeObject instanceof ImportObject) {
            return ClassName.bestGuess(schemeObject.fullName)
        } else {
            return ClassName.bestGuess(argumentName)
        }
    }

    static Pair<String, TypeName> getTypeNameWithArguments(TypeName parentTypeName, String genericString, Map<String, SchemeObject> objects) {
        List<TypeName> arguments = new ArrayList<>()
        genericString = genericString.replace(" ", "")
        while (!genericString.isEmpty()) {
            int nextComma = genericString.indexOf(',')
            int nextLeft = genericString.indexOf('<')
            int nextRight = genericString.indexOf('>')
            if (nextComma > 0 && nextComma < nextRight && (nextLeft == -1 || nextComma < nextLeft)) {
                arguments.add(resolveType(genericString.substring(0, nextComma), objects))
                genericString = genericString.substring(nextComma + 1)
                continue
            }
            if (nextRight == -1) {
                arguments.add(resolveType(genericString), objects)
                break
            }
            if (nextLeft == -1 || nextRight < nextLeft) {
                arguments.add(resolveType(genericString.substring(0, nextRight), objects))
                genericString = nextRight < genericString.length() - 1 ? genericString.substring(nextRight + 1) : ""
                break
            }
            TypeName innerType = resolveType(genericString.substring(0, nextLeft), objects)
            genericString = genericString.substring(nextLeft + 1)
            Pair<String, TypeName> innerArgs = getTypeNameWithArguments(innerType, genericString, objects)
            genericString = innerArgs.key.substring(1)
            arguments.add(innerArgs.value)
        }
        return new Pair<String, TypeName>(genericString, ParameterizedTypeName.get(parentTypeName, (TypeName[]) arguments.toArray()))
    }

    static TypeName resolveTypeName(String typeString, Map<String, SchemeObject> objects) {
        String simpleName = FieldInfo.getTypeSimpleName(typeString)
        String genericsSuffix = typeString.indexOf("<") > 0 ? typeString.substring(typeString.indexOf("<")) : null
        SchemeObject schemeObject = objects.get(simpleName)
        if (schemeObject instanceof ImportObject) {
            if (genericsSuffix != null) {
                return getTypeNameWithArguments(ClassName.bestGuess(schemeObject.fullName), genericsSuffix.substring(1), objects).value
            } else {
                return ClassName.bestGuess(schemeObject.fullName)
            }
        } else {
            if (genericsSuffix != null) {
                return getTypeNameWithArguments(ClassName.bestGuess(simpleName), genericsSuffix.substring(1), objects)
            } else {
                return ClassName.bestGuess(simpleName)
            }
        }
    }

}

class FieldInfo {

    static upperStartName(String name) {
        if (name.isEmpty()) {
            throw new Exception("Empty name of field")
        }
        if (name.length() == 1) {
            return name.charAt(0).toUpperCase()
        }
        return name.charAt(0).toUpperCase().toString() + name.substring(1)
    }

    static String getTypeSimpleName(String typeString) {
        String result = typeString.trim()
        if (result.indexOf('.') > 0) {
            result = result.substring(result.lastIndexOf('.') + 1)
        }
        if (result.indexOf('<') > 0) {
            result = result.substring(0, result.indexOf('<'))
        }
        return result;
    }

    final String apiName
    final boolean nullable
    final boolean required
    final boolean nonEmptyCollection
    final boolean solidCollection
    final FieldType fieldType
    final TypeName typeName

    FieldInfo(String apiName, String typeString, String subTypeString, Map<String, SchemeObject> objects) {
        this.apiName = apiName
        solidCollection = typeString.endsWith('%')
        if (solidCollection) {
            typeString = typeString.substring(0, typeString.length() - 1)
        }
        nonEmptyCollection = typeString.endsWith('|')
        if (nonEmptyCollection) {
            typeString = typeString.substring(0, typeString.length() - 1)
        }
        required = typeString.endsWith('*')
        if (required) {
            typeString = typeString.substring(0, typeString.length() - 1)
        }
        nullable = typeString.endsWith('?')
        if (nullable) {
            typeString = typeString.substring(0, typeString.length() - 1)
        }
        String original = typeString
        typeString = getTypeSimpleName(typeString);
        fieldType = FieldType.get(typeString, objects);
        if (fieldType.typeName != null) {
            if (fieldType == FieldType.ARRAY) {
                typeName = ParameterizedTypeName.get(fieldType.typeName, TypeNameUtils.resolveTypeName(subTypeString, objects))
            } else if (fieldType == FieldType.MAP) {
                typeName = ParameterizedTypeName.get(fieldType.typeName, ClassName.get(String.class), TypeNameUtils.resolveTypeName(subTypeString, objects))
            } else {
                typeName = fieldType.typeName
            }
        } else if (fieldType != FieldType.GENERIC) {
            typeName = TypeNameUtils.resolveTypeName(original, objects)
        } else {
            // generic
            typeName = ClassName.bestGuess(typeString)
        }
    }

    FieldSpec createField(String name) {
        return FieldSpec.builder(typeName, name, Modifier.PRIVATE)
                .addAnnotation(AnnotationSpec.builder(ClassName.bestGuess("com.bluelinelabs.logansquare.annotation.JsonField"))
                .addMember("name", "\$S", apiName)
                .build())
                .build()
    }

    static boolean checkNameStartsWith(String name, String prefix) {
        return name.length() > prefix.length() && name.startsWith(prefix) && name.charAt(prefix.length()).isUpperCase()
    }

    String getGetterPrefix(String name) {
        if (fieldType != FieldType.BOOLEAN) {
            return "get"
        }
        if (checkNameStartsWith(name, "is")) {
            return "is"
        } else if (checkNameStartsWith(name, "has")) {
            return "has"
        } else if (checkNameStartsWith(name, "have")) {
            return "have"
        }
        return "get"
    }

    MethodSpec createGetter(String name) {
        String getterPrefix = getGetterPrefix(name);
        final MethodSpec.Builder builder = MethodSpec.methodBuilder(getterPrefix.equals("get")
                ? getterPrefix + upperStartName(name)
                : getterPrefix + upperStartName(name.substring(getterPrefix.length())))
                .returns(typeName)
                .addModifiers(Modifier.PUBLIC)
        if (!typeName.isPrimitive()) {
            builder.addAnnotation(AnnotationSpec.builder(nullable
                    ? ClassName.bestGuess("android.support.annotation.Nullable")
                    : ClassName.bestGuess("android.support.annotation.NonNull"))
                    .build());
        }

        if (fieldType == FieldType.MAP) {
            builder.addStatement("return \$T.unmodifiableMap(\$L)", ClassName.get(Collections.class), name)
        } else if (fieldType == FieldType.ARRAY) {
            builder.addStatement("return \$T.unmodifiableList(\$L)", ClassName.get(Collections.class), name)
        } else {
            builder.addStatement("return \$L", name)
        }
        return builder.build()
    }

    MethodSpec createSetter(String name) {
        final ParameterSpec.Builder parameterBuilder = ParameterSpec.builder(typeName, name, Modifier.FINAL)
        if (!typeName.isPrimitive()) {
            parameterBuilder.addAnnotation(AnnotationSpec.builder(nullable
                    ? ClassName.bestGuess("android.support.annotation.Nullable")
                    : ClassName.bestGuess("android.support.annotation.NonNull"))
                    .build());
        }
        final MethodSpec.Builder builder = MethodSpec.methodBuilder("set" + upperStartName(name))
                .addParameter(parameterBuilder.build())
                .addModifiers(Modifier.PUBLIC)

        if (fieldType == FieldType.MAP) {
            builder.addStatement("this.\$L = \$T.unmodifiableMap(\$L)", name, ClassName.get(Collections.class), name)
        } else if (fieldType == FieldType.ARRAY) {
            builder.addStatement("this.\$L = \$T.unmodifiableList(\$L)", name, ClassName.get(Collections.class), name)
        } else {
            builder.addStatement("this.\$L = \$L", name, name)
        }

        return builder.build()
    }

    void addValidateStatements(String name, MethodSpec.Builder validateMethod) {
        final String prefix
        if (!nullable) {
            prefix = ""
            validateMethod.addStatement("validateNotNull(\$L)", name)
        } else {
            prefix = "if(" + name + "!=null)"
        }
        if (fieldType == FieldType.ARRAY) {
            if (nonEmptyCollection) {
                validateMethod.addStatement(prefix + "validateCollectionNotEmpty(\$L)", name)
            }
            if (solidCollection) {
                validateMethod.addStatement(prefix + "validateCollection(\$L, CollectionValidationRule.EXCEPTION_IF_ANY_INVALID)", name)
            } else if (nonEmptyCollection) {
                validateMethod.addStatement(prefix + "validateCollection(\$L, CollectionValidationRule.EXCEPTION_IF_ALL_INVALID)", name)
            } else {
                validateMethod.addStatement(prefix + "validateCollection(\$L, CollectionValidationRule.REMOVE_INVALID_ITEMS)", name)
            }
        } else if (fieldType == FieldType.MAP) {
            if (nonEmptyCollection) {
                validateMethod.addStatement(prefix + "validateCollectionNotEmpty(\$L.values())", name)
            }
            validateMethod.addStatement(prefix + "validateCollection(\$L.values(), CollectionValidationRule.EXCEPTION_IF_ANY_INVALID)", name)
        } else if (fieldType == FieldType.MODEL) {
            validateMethod.addStatement(prefix + "\$L.validate()", name)
        } else if (fieldType == FieldType.GENERIC || fieldType == FieldType.IMPORTED_MODEL) {
            validateMethod.addStatement("if(\$L instanceof \$T) ((\$T)\$L).validate()", name,
                    ClassName.bestGuess("ru.touchin.templates.ApiModel"),
                    ClassName.bestGuess("ru.touchin.templates.ApiModel"), name)
        }
    }

}

class ClassObject extends SchemeObject {

    static final String SIGNATURE = "class"

    final String name
    final Map<String, FieldInfo> fieldsInfo = new HashMap<>()
    final List<String> typeVariables = new ArrayList<>()
    TypeName superclass

    ClassObject(String firstLine) {
        name = firstLine.substring(SIGNATURE.length()).trim()
    }

    @Override
    void writeToFile(File directory, Map<String, SchemeObject> objects) {
        TypeSpec.Builder classBuilder = TypeSpec.classBuilder(name)
                .addModifiers(Modifier.PUBLIC)
                .addAnnotation(AnnotationSpec.builder(ClassName.bestGuess("com.bluelinelabs.logansquare.annotation.JsonObject"))
                .build())

        if (superclass != null) {
            classBuilder.superclass(superclass)
        } else {
            classBuilder.superclass(ClassName.bestGuess("ru.touchin.templates.logansquare.LoganSquareJsonModel"))
        }

        for (String typeVariable : typeVariables) {
            classBuilder.addTypeVariable(TypeVariableName.get(typeVariable))
        }

        classBuilder.addMethod(MethodSpec.constructorBuilder()
                .addModifiers(Modifier.PUBLIC)
                .build())

        MethodSpec.Builder equalsMethod = MethodSpec.methodBuilder("equals")
                .addModifiers(Modifier.PUBLIC)
                .addAnnotation(Override.class)
                .returns(TypeName.BOOLEAN)
                .addParameter(ParameterSpec.builder(ClassName.get(Object.class), "object", Modifier.FINAL)
                .addAnnotation(ClassName.bestGuess("android.support.annotation.Nullable"))
                .build())
                .addStatement("if (this == object) return true")
                .addStatement("if (object == null || getClass() != object.getClass()) return false")
                .addStatement("final \$T that = (\$T) object", ClassName.bestGuess(name), ClassName.bestGuess(name))

        MethodSpec.Builder hashCodeMethod = MethodSpec.methodBuilder("hashCode")
                .addModifiers(Modifier.PUBLIC)
                .addAnnotation(Override.class)
                .returns(TypeName.INT)

        MethodSpec.Builder validateMethod = MethodSpec.methodBuilder("validate")
                .addModifiers(Modifier.PUBLIC)
                .addAnnotation(Override.class)
                .addException(ClassName.bestGuess("ValidationException"))
                .addStatement("super.validate()")

        boolean first = true
        CodeBlock.Builder equalsStatement = CodeBlock.builder()
        CodeBlock.Builder hashCodeStatement = CodeBlock.builder()

        for (Map.Entry<String, FieldInfo> entry : fieldsInfo) {
            classBuilder.addField(entry.value.createField(entry.key))
            classBuilder.addMethod(entry.value.createGetter(entry.key))
            classBuilder.addMethod(entry.value.createSetter(entry.key))
            entry.value.addValidateStatements(entry.key, validateMethod)
            if (first) {
                if (superclass == null) {
                    hashCodeStatement.add("return \$T.hashCode(\$L", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"), entry.key)
                    equalsStatement.add("return \$T.equals(\$L, that.\$L)", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"),
                            entry.key, entry.key)
                } else {
                    hashCodeStatement.add("return \$T.hashCode(super.hashCode(), \$L", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"), entry.key)
                    equalsStatement.add("return super.equals(that) && \$T.equals(\$L, that.\$L)", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"),
                            entry.key, entry.key)
                }
            } else {
                if (entry.value.fieldType == FieldType.MAP) {
                    equalsStatement.add("\n&& \$T.isMapsEquals(\$L, that.\$L)", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"),
                            entry.key, entry.key)
                } else if (entry.value.fieldType == FieldType.ARRAY) {
                    equalsStatement.add("\n&& \$T.isCollectionsEquals(\$L, that.\$L)", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"),
                            entry.key, entry.key)
                } else {
                    equalsStatement.add("\n&& \$T.equals(\$L, that.\$L)", ClassName.bestGuess("ru.touchin.roboswag.core.utils.ObjectUtils"),
                            entry.key, entry.key)
                }

                hashCodeStatement.add(", \$L", entry.key)
            }
            first = false
        }
        equalsStatement.add(";")
        hashCodeStatement.add(");")

        classBuilder.addMethod(validateMethod.build())
        classBuilder.addMethod(equalsMethod.addCode(equalsStatement.build()).build())
        classBuilder.addMethod(hashCodeMethod.addCode(hashCodeStatement.build()).build())

        JavaFile.builder("com.touchin.sberinkas", classBuilder.build())
                .indent("    ")
                .build().writeTo(directory);
    }

    @Override
    void readLine(final String line, Map<String, SchemeObject> objects) {
        if (line.startsWith("typeVariables")) {
            for (String typeVariable : line.substring("typeVariables".length()).replace(" ", "").split(",")) {
                typeVariables.add(typeVariable)
            }
            return
        }

        if (line.startsWith("extends")) {
            superclass = TypeNameUtils.resolveTypeName(line.substring("extends".length()).replace(" ", ""), objects)
            return
        }

        String[] parts = line.split(':')
        String fieldName = parts[0].trim();
        String apiName = parts[1].trim();
        String type = parts[2].trim();
        String subType = parts.length > 3 ? parts[3].trim() : null;

        if (fieldsInfo.containsKey(fieldName)) {
            throw new Exception("Field of '" + name + "' already added: " + fieldName)
        }
        fieldsInfo.put(fieldName, new FieldInfo(apiName, type, subType, objects))
    }

}

android.applicationVariants.all {
    variant ->
        File generatedModels = new File("${project.buildDir}/generated/source/models/${variant.dirName}")
        File schemeFile = new File("${project.projectDir}/src/main/res/raw/scheme.txt")

        def apiModelsGenerationTask = tasks.create("apiModelsGeneration${variant.name}") << {

            BufferedReader reader = new BufferedReader(new FileReader(schemeFile))
            String line
            Map<String, SchemeObject> schemeObjects = new HashMap<>()
            schemeObjects.put("List", new ImportObject("import java.util.List"))
            schemeObjects.put("Map", new ImportObject("import java.util.Map"))
            SchemeObject currentSchemeObject = null
            while ((line = reader.readLine()) != null) {
                if (line.startsWith(EnumObject.SIGNATURE)) {
                    currentSchemeObject = new EnumObject(line)
                    schemeObjects.put(currentSchemeObject.name, currentSchemeObject)
                } else if (line.startsWith(ClassObject.SIGNATURE)) {
                    currentSchemeObject = new ClassObject(line)
                    schemeObjects.put(currentSchemeObject.name, currentSchemeObject)
                } else if (line.startsWith(ImportObject.SIGNATURE)) {
                    currentSchemeObject = new ImportObject(line)
                    schemeObjects.put(currentSchemeObject.name, currentSchemeObject)
                } else if (currentSchemeObject != null) {
                    currentSchemeObject.lines.add(line)
                } else if (!line.trim().isEmpty()) {
                    throw new Exception("No objects in scheme")
                }
            }

            for (SchemeObject schemeObject : schemeObjects.values()) {
                for (String objectLine : schemeObject.lines) {
                    schemeObject.readLine(objectLine, schemeObjects)
                }
                schemeObject.writeToFile(generatedModels, schemeObjects)
            }
        }

        apiModelsGenerationTask.description = 'Generates API models'
        variant.registerJavaGeneratingTask apiModelsGenerationTask, generatedModels
}