package io.trygvis.persistence;

import io.trygvis.container.compiler.NotImplementedException;
import io.trygvis.container.compiler.SqlUnitModel;
import io.trygvis.container.compiler.model.ClassG;
import io.trygvis.container.compiler.model.ParameterRef;
import io.trygvis.container.compiler.model.TypeRef;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import static io.trygvis.persistence.FieldMirror.PrimitiveFieldMirror;
import static io.trygvis.persistence.FieldMirror.ReferenceFieldMirror;
import static java.lang.String.format;
import static org.apache.commons.lang.StringUtils.join;

public class EntityMirror implements Comparable<EntityMirror> {
    public final GeneratorConfiguration generatorConfiguration;
    public final List<FieldMirror> fields = new ArrayList<>();
    public final List<FieldMirror> idFields = new ArrayList<>();
    public final TypeRef type;
    public final String tableName;
    public final TypeRef daoType;

    public EntityMirror(GeneratorConfiguration generatorConfiguration, TypeRef type, String tableName) {
        this.generatorConfiguration = generatorConfiguration;
        this.type = type;
        this.tableName = tableName;

        this.daoType = new TypeRef(type.name + "Dao");
    }

    public void add(FieldMirror field) {
        fields.add(field);
        if (field.id) {
            idFields.add(field);
        }
    }

    public FieldMirror getIdField() {
        return idFields.get(0);
    }

    public String createTableSql(SqlUnitModel unit) {
        List<String> columns = new ArrayList<>();
        for (FieldMirror field : fields) {
            String s;
            if (field instanceof PrimitiveFieldMirror) {
                TypeHandler typeHandler = generatorConfiguration.typeHandler(field.type);
                s = "  " + field.sqlName + " " + typeHandler.sqlType(field);
                if (field.id) {
                    s += " PRIMARY KEY";
                } else if (field.notNull) {
                    s += " NOT NULL";
                } else if (field.unique) {
                    s += " UNIQUE";
                }
            } else if (field instanceof ReferenceFieldMirror) {
                ReferenceFieldMirror ref = (ReferenceFieldMirror) field;
                EntityMirror referenced = unit.get(ref.type);
                if(referenced.idFields.size() == 1) {
                    FieldMirror idField = referenced.idFields.get(0);
                    TypeHandler typeHandler = generatorConfiguration.typeHandler(idField.type);
                    s = "  " + field.sqlName + " " + typeHandler.sqlType(field);
                    s += " REFERENCES " + referenced.tableName + "(" + idField.sqlName + ")";
                    if (field.notNull) {
                        s += " NOT NULL";
                    } else if (field.unique) {
                        s += " UNIQUE";
                    }
                }
                else {
                    throw new NotImplementedException();
                }
            } else {
                throw new RuntimeException("Unknown field type: " + field.getClass());
            }
            columns.add(s);
        }

        return format("CREATE TABLE " + tableName + "(%n" +
                join(columns, ",%n") +
                "%n);");
    }

    public String dropTableSql() {
        return "DROP TABLE " + tableName + ";";
    }

    public String insertIntoSql() {
        List<String> names = new ArrayList<>();
        List<String> placeholders = new ArrayList<>();
        for (FieldMirror field : fields) {
            names.add(field.sqlName);
            placeholders.add("?");
        }

        return "INSERT INTO " + tableName + "(" + join(names, ", ") + ") " +
                "VALUES(" + join(placeholders, ", ") + ");";
    }

    public String deleteFromSql() {
        List<String> ss = new ArrayList<>();
        for (FieldMirror field : idFields) {
            ss.add(field.sqlName + "=?");
        }

        return "DELETE FROM " + tableName + " WHERE " + join(ss, " AND ") + ";";
    }

    public void insertInto(SqlUnitModel unit, ClassG g) {
        TypeRef conType = g.addImport(Connection.class);
        TypeRef psType = g.addImport(PreparedStatement.class);
        TypeRef objectType = g.addImport(type);
        ParameterRef con = new ParameterRef(conType, "con");
        ParameterRef object = new ParameterRef(objectType, "o");

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

        body.add("try(" + psType.name + " stmt = " + con.name + ".prepareStatement(insertIntoSql)) {");
        for (int i = 0; i < fields.size(); i++) {
            FieldMirror field = fields.get(i);
            if(field instanceof PrimitiveFieldMirror) {
                TypeHandler typeHandler = generatorConfiguration.typeHandler(field.type);
                body.add("    stmt." + typeHandler.setter(i + 1, "o." + field.javaName) + ";");
            } else if (field instanceof ReferenceFieldMirror) {
                ReferenceFieldMirror ref = (ReferenceFieldMirror) field;
                EntityMirror referenced = unit.get(ref.type);
                FieldMirror idField = referenced.getIdField();
                TypeHandler typeHandler = generatorConfiguration.typeHandler(idField.type);
                body.add("    stmt." + typeHandler.setter(i + 1, "o." + field.javaName + "." + idField.javaName) + ";");
            }
        }
        body.add("    stmt.executeUpdate();");
        body.add("}");

        g.addStaticMethod(body, TypeRef.VOID, "insertInto", con, object).
                exception(g.addImport(SQLException.class));
    }

    public void delete(ClassG g) {
        TypeRef conType = g.addImport(Connection.class);
        TypeRef objectType = g.addImport(type);
        ParameterRef con = new ParameterRef(conType, "con");
        ParameterRef o = new ParameterRef(objectType, "o");

        List<String> arguments = new ArrayList<>();
        arguments.add(con.name);
        for (FieldMirror field : idFields) {
            arguments.add(o.name + "." + field.javaName);
        }
        List<String> body = new ArrayList<>();
        body.add("deleteById(" + join(arguments, ", ") + ");");

        g.addStaticMethod(body, TypeRef.VOID, "delete", con, o).
                exception(g.addImport(SQLException.class));
    }

    public void deleteById(ClassG g) {
        TypeRef conType = g.addImport(Connection.class);
        TypeRef psType = g.addImport(PreparedStatement.class);
        ParameterRef con = new ParameterRef(conType, "con");

        ParameterRef[] parameters = new ParameterRef[idFields.size() + 1];
        parameters[0] = con;

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

        body.add("try(" + psType.name + " stmt = " + con.name + ".prepareStatement(deleteFromSql)) {");
        for (int i = 0; i < idFields.size(); i++) {
            FieldMirror field = idFields.get(i);
            TypeHandler typeHandler = generatorConfiguration.typeHandler(field.type);
            ParameterRef p = new ParameterRef(field.type, field.javaName);
            parameters[i + 1] = p;
            body.add("    stmt." + typeHandler.setter(i + 1, field.javaName) + ";");
        }
        body.add("    stmt.executeUpdate();");
        body.add("}");

        g.addStaticMethod(body, TypeRef.VOID, "deleteById", parameters).
                exception(g.addImport(SQLException.class));
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof EntityMirror)) return false;

        EntityMirror that = (EntityMirror) o;

        return type.equals(that.type);
    }

    @Override
    public int hashCode() {
        return type.hashCode();
    }

    @Override
    public int compareTo(EntityMirror o) {
        return type.compareTo(o.type);
    }
}