import {ConfigurationHandler, PathConfigurationFrom} from "./ConfigurationHandler";
import {
  AnyMenuItem,
  CollectionMenuItem,
  FieldMenuItem,
  FieldMenuItemContext,
  FieldMenuItemSaveValue,
  MenuItem,
  MenuItemType,
  PromptMenuItem
} from "../Menu/MenuRenderer.types";
import {TraversalPath} from "../Menu/MenuTraversal.types";
import {
  channelMention,
  ChannelSelectMenuBuilder,
  ChannelType,
  italic,
  StringSelectMenuBuilder,
  TextInputBuilder,
  TextInputStyle
} from "discord.js";
import {MessageActionRowComponentBuilder} from "@discordjs/builders";
import {TransformerType} from "./ConfigurationTransformer";

type FieldHandlerMenuItem = MenuItem & (Partial<PromptMenuItem> | Partial<FieldMenuItem>);
type HandlerMenuItem =
  FieldHandlerMenuItem | CollectionMenuItem<HandlerMenuItem>

export class MenuHandler {
  constructor(
    private readonly config: ConfigurationHandler,
  ) {
  }
  
  public fillMenuItems(
    menuItems: HandlerMenuItem[]
  ): AnyMenuItem[] {
    const handler = this;

    function resolve(path: TraversalPath, menuItem: HandlerMenuItem): AnyMenuItem {
      path = [...path, menuItem.traversalKey];
      
      if (menuItem.type === MenuItemType.Collection) {
        menuItem.children = menuItem.children.map((nextMenuItem) => resolve(path, nextMenuItem))
        return <CollectionMenuItem>menuItem;
      }

      const transformerType = handler.config.transformer.getTransformerType(path.join('.'));
      if (transformerType === undefined || transformerType === null) {
        throw new Error(`Can't resolve type for '${path.join('.')}'`);
      }
      
      menuItem.type = handler.findType(transformerType);
      
      menuItem.setValue = handler.setValue.bind(handler);
      menuItem.getCurrentValue = handler.findCurrentValueMethod(transformerType);
      menuItem.getActionRowBuilder = handler.findActionRowBuilderMethod(transformerType);
      
      return <AnyMenuItem>menuItem;
    }

    return menuItems.map((menuItem) => resolve([], menuItem))
  }
  
  private findType(transformer: TransformerType): MenuItemType.Field | MenuItemType.Prompt
  {
    switch (transformer) {
      case TransformerType.String:
      case TransformerType.Paragraph:
        return MenuItemType.Prompt;
      default:
        return MenuItemType.Field;
    }
  }

  private findCurrentValueMethod(transformer: TransformerType): (context: FieldMenuItemContext) => string
  {
    switch (transformer) {
      case TransformerType.Channel:
        return this.getChannelValue.bind(this);
      case TransformerType.PermissionBoolean:
        return this.getPermissionBooleanValue.bind(this);
      case TransformerType.String:
      case TransformerType.Paragraph:
        return this.getStringValue.bind(this);
    }
  }
  
  private findActionRowBuilderMethod(transformer: TransformerType):
    ((context: FieldMenuItemContext) => MessageActionRowComponentBuilder) | ((context: FieldMenuItemContext) => TextInputBuilder)
  {
    switch (transformer) {
      case TransformerType.Channel:
        return this.getChannelMenuBuilder.bind(this);
      case TransformerType.PermissionBoolean:
        return this.getPermissionBooleanBuilder.bind(this);
      case TransformerType.String:
        return this.getStringBuilder.bind(this);
      case TransformerType.Paragraph:
        return this.getTextareaBuilder.bind(this);
    }
  }

  private getChannelValue(context: FieldMenuItemContext): string {
    const value = this.config.getConfigurationByPath(context.path.join('.'));
    
    const isDefault = value.from === PathConfigurationFrom.Default;
    const display = !value ? "None" : channelMention(<string>value.value);
    
    if (isDefault)  {
      return italic(`Default (${display})`)
    }
    return display;
  }

  private getChannelMenuBuilder(): MessageActionRowComponentBuilder {
    return new ChannelSelectMenuBuilder()
      .setChannelTypes(ChannelType.GuildText)
      .setPlaceholder("New Value");
  }

  private getPermissionBooleanValue(context: FieldMenuItemContext) {
    const value = this.config.getConfigurationByPath(context.path.join('.'));

    const isDefault = value.from === PathConfigurationFrom.Default;
    const display = value.value === null ? "None" : value.value == true ? "Allowed" : "Disallowed";

    if (isDefault)  {
      return italic(`Default (${display})`)
    }
    return display;
  }

  private getPermissionBooleanBuilder() {
    return new StringSelectMenuBuilder()
      .setOptions(
        [
          {
            label: "Allow",
            value: "1"
          },
          {
            label: "Disallow",
            value: "0"
          }
        ]
      )
  }

  private getStringValue(context: FieldMenuItemContext): string {
    const value = this.config.getConfigurationByPath(context.path.join('.'));

    return value.value === null ? "" : <string>value.value;
  }

  private getStringBuilder(): TextInputBuilder {
    return new TextInputBuilder()
      .setStyle(TextInputStyle.Short)
      .setMaxLength(100)
  }
  private getTextareaBuilder(): TextInputBuilder {
    return new TextInputBuilder()
      .setStyle(TextInputStyle.Paragraph)
      .setMaxLength(2048)
  }


  private setValue(value: FieldMenuItemSaveValue[]|string, context: FieldMenuItemContext): void {
    const savedValue = typeof value !== 'string' ?
      value.join('; ') :
      value;

    this.config.save(context.path.join('.'), savedValue);
  }
}