import { ChatMessage, useAppConfig, useChatStore } from "../store";
import Locale from "../locales";
import styles from "./exporter.module.scss";
import { List, ListItem, Modal, showToast } from "./ui-lib";
import { IconButton } from "./button";
import { copyToClipboard, downloadAs, useMobileScreen } from "../utils";

import CopyIcon from "../icons/copy.svg";
import LoadingIcon from "../icons/three-dots.svg";
import ChatGptIcon from "../icons/chatgpt.png";
import ShareIcon from "../icons/share.svg";
import BotIcon from "../icons/bot.png";

import DownloadIcon from "../icons/download.svg";
import { useMemo, useRef, useState } from "react";
import { MessageSelector, useMessageSelector } from "./message-selector";
import { Avatar } from "./emoji";
import dynamic from "next/dynamic";
import NextImage from "next/image";

import { toBlob, toPng } from "html-to-image";
import { DEFAULT_MASK_AVATAR } from "../store/mask";

const Markdown = dynamic(async () => (await import("./markdown")).Markdown, {
  loading: () => <LoadingIcon />,
});

export function ExportMessageModal(props: { onClose: () => void }) {
  return (
    <div className="modal-mask">
      <Modal title={Locale.Export.Title} onClose={props.onClose}>
        <div style={{ minHeight: "40vh" }}>
          <MessageExporter />
        </div>
      </Modal>
    </div>
  );
}

function useSteps(
  steps: Array<{
    name: string;
    value: string;
  }>,
) {
  const stepCount = steps.length;
  const [currentStepIndex, setCurrentStepIndex] = useState(0);
  const nextStep = () =>
    setCurrentStepIndex((currentStepIndex + 1) % stepCount);
  const prevStep = () =>
    setCurrentStepIndex((currentStepIndex - 1 + stepCount) % stepCount);

  return {
    currentStepIndex,
    setCurrentStepIndex,
    nextStep,
    prevStep,
    currentStep: steps[currentStepIndex],
  };
}

function Steps<
  T extends {
    name: string;
    value: string;
  }[],
>(props: { steps: T; onStepChange?: (index: number) => void; index: number }) {
  const steps = props.steps;
  const stepCount = steps.length;

  return (
    <div className={styles["steps"]}>
      <div className={styles["steps-progress"]}>
        <div
          className={styles["steps-progress-inner"]}
          style={{
            width: `${((props.index + 1) / stepCount) * 100}%`,
          }}
        ></div>
      </div>
      <div className={styles["steps-inner"]}>
        {steps.map((step, i) => {
          return (
            <div
              key={i}
              className={`${styles["step"]} ${
                styles[i <= props.index ? "step-finished" : ""]
              } ${i === props.index && styles["step-current"]} clickable`}
              onClick={() => {
                props.onStepChange?.(i);
              }}
              role="button"
            >
              <span className={styles["step-index"]}>{i + 1}</span>
              <span className={styles["step-name"]}>{step.name}</span>
            </div>
          );
        })}
      </div>
    </div>
  );
}

export function MessageExporter() {
  const steps = [
    {
      name: Locale.Export.Steps.Select,
      value: "select",
    },
    {
      name: Locale.Export.Steps.Preview,
      value: "preview",
    },
  ];
  const { currentStep, setCurrentStepIndex, currentStepIndex } =
    useSteps(steps);
  const formats = ["text", "image"] as const;
  type ExportFormat = (typeof formats)[number];

  const [exportConfig, setExportConfig] = useState({
    format: "image" as ExportFormat,
    includeContext: true,
  });

  function updateExportConfig(updater: (config: typeof exportConfig) => void) {
    const config = { ...exportConfig };
    updater(config);
    setExportConfig(config);
  }

  const chatStore = useChatStore();
  const session = chatStore.currentSession();
  const { selection, updateSelection } = useMessageSelector();
  const selectedMessages = useMemo(() => {
    const ret: ChatMessage[] = [];
    if (exportConfig.includeContext) {
      ret.push(...session.mask.context);
    }
    ret.push(...session.messages.filter((m, i) => selection.has(m.id ?? i)));
    return ret;
  }, [
    exportConfig.includeContext,
    session.messages,
    session.mask.context,
    selection,
  ]);

  return (
    <>
      <Steps
        steps={steps}
        index={currentStepIndex}
        onStepChange={setCurrentStepIndex}
      />

      <div className={styles["message-exporter-body"]}>
        {currentStep.value === "select" && (
          <>
            <List>
              <ListItem
                title={Locale.Export.Format.Title}
                subTitle={Locale.Export.Format.SubTitle}
              >
                <select
                  value={exportConfig.format}
                  onChange={(e) =>
                    updateExportConfig(
                      (config) =>
                        (config.format = e.currentTarget.value as ExportFormat),
                    )
                  }
                >
                  {formats.map((f) => (
                    <option key={f} value={f}>
                      {f}
                    </option>
                  ))}
                </select>
              </ListItem>
              <ListItem
                title={Locale.Export.IncludeContext.Title}
                subTitle={Locale.Export.IncludeContext.SubTitle}
              >
                <input
                  type="checkbox"
                  checked={exportConfig.includeContext}
                  onChange={(e) => {
                    updateExportConfig(
                      (config) =>
                        (config.includeContext = e.currentTarget.checked),
                    );
                  }}
                ></input>
              </ListItem>
            </List>
            <MessageSelector
              selection={selection}
              updateSelection={updateSelection}
              defaultSelectAll
            />
          </>
        )}

        {currentStep.value === "preview" && (
          <>
            {exportConfig.format === "text" ? (
              <MarkdownPreviewer
                messages={selectedMessages}
                topic={session.topic}
              />
            ) : (
              <ImagePreviewer
                messages={selectedMessages}
                topic={session.topic}
              />
            )}
          </>
        )}
      </div>
    </>
  );
}

export function PreviewActions(props: {
  download: () => void;
  copy: () => void;
  showCopy?: boolean;
}) {
  return (
    <div className={styles["preview-actions"]}>
      {props.showCopy && (
        <IconButton
          text={Locale.Export.Copy}
          bordered
          shadow
          icon={<CopyIcon />}
          onClick={props.copy}
        ></IconButton>
      )}
      <IconButton
        text={Locale.Export.Download}
        bordered
        shadow
        icon={<DownloadIcon />}
        onClick={props.download}
      ></IconButton>
      <IconButton
        text={Locale.Export.Share}
        bordered
        shadow
        icon={<ShareIcon />}
        onClick={() => showToast(Locale.WIP)}
      ></IconButton>
    </div>
  );
}

function ExportAvatar(props: { avatar: string }) {
  if (props.avatar === DEFAULT_MASK_AVATAR) {
    return (
      <NextImage
        src={BotIcon.src}
        width={30}
        height={30}
        alt="bot"
        className="user-avatar"
      />
    );
  }

  return <Avatar avatar={props.avatar}></Avatar>;
}

export function ImagePreviewer(props: {
  messages: ChatMessage[];
  topic: string;
}) {
  const chatStore = useChatStore();
  const session = chatStore.currentSession();
  const mask = session.mask;
  const config = useAppConfig();

  const previewRef = useRef<HTMLDivElement>(null);

  const copy = () => {
    const dom = previewRef.current;
    if (!dom) return;
    toBlob(dom).then((blob) => {
      if (!blob) return;
      try {
        navigator.clipboard
          .write([
            new ClipboardItem({
              "image/png": blob,
            }),
          ])
          .then(() => {
            showToast(Locale.Copy.Success);
          });
      } catch (e) {
        console.error("[Copy Image] ", e);
        showToast(Locale.Copy.Failed);
      }
    });
  };

  const isMobile = useMobileScreen();

  const download = () => {
    const dom = previewRef.current;
    if (!dom) return;
    toPng(dom)
      .then((blob) => {
        if (!blob) return;

        if (isMobile) {
          const image = new Image();
          image.src = blob;
          const win = window.open("");
          win?.document.write(image.outerHTML);
        } else {
          const link = document.createElement("a");
          link.download = `${props.topic}.png`;
          link.href = blob;
          link.click();
        }
      })
      .catch((e) => console.log("[Export Image] ", e));
  };

  return (
    <div className={styles["image-previewer"]}>
      <PreviewActions copy={copy} download={download} showCopy={!isMobile} />
      <div
        className={`${styles["preview-body"]} ${styles["default-theme"]}`}
        ref={previewRef}
      >
        <div className={styles["chat-info"]}>
          <div className={styles["logo"] + " no-dark"}>
            <NextImage
              src={ChatGptIcon.src}
              alt="logo"
              width={50}
              height={50}
            />
          </div>

          <div>
            <div className={styles["main-title"]}>ChatGPT Next Web</div>
            <div className={styles["sub-title"]}>
              github.com/Yidadaa/ChatGPT-Next-Web
            </div>
            <div className={styles["icons"]}>
              <ExportAvatar avatar={config.avatar} />
              <span className={styles["icon-space"]}>&</span>
              <ExportAvatar avatar={mask.avatar} />
            </div>
          </div>
          <div>
            <div className={styles["chat-info-item"]}>
              Model: {mask.modelConfig.model}
            </div>
            <div className={styles["chat-info-item"]}>
              Messages: {props.messages.length}
            </div>
            <div className={styles["chat-info-item"]}>
              Topic: {session.topic}
            </div>
            <div className={styles["chat-info-item"]}>
              Time:{" "}
              {new Date(
                props.messages.at(-1)?.date ?? Date.now(),
              ).toLocaleString()}
            </div>
          </div>
        </div>
        {props.messages.map((m, i) => {
          return (
            <div
              className={styles["message"] + " " + styles["message-" + m.role]}
              key={i}
            >
              <div className={styles["avatar"]}>
                <ExportAvatar
                  avatar={m.role === "user" ? config.avatar : mask.avatar}
                />
              </div>

              <div className={`${styles["body"]} `}>
                <Markdown
                  content={m.content}
                  fontSize={config.fontSize}
                  defaultShow
                />
              </div>
            </div>
          );
        })}
      </div>
    </div>
  );
}

export function MarkdownPreviewer(props: {
  messages: ChatMessage[];
  topic: string;
}) {
  const mdText =
    `# ${props.topic}\n\n` +
    props.messages
      .map((m) => {
        return m.role === "user"
          ? `## ${Locale.Export.MessageFromYou}:\n${m.content}`
          : `## ${Locale.Export.MessageFromChatGPT}:\n${m.content.trim()}`;
      })
      .join("\n\n");

  const copy = () => {
    copyToClipboard(mdText);
  };
  const download = () => {
    downloadAs(mdText, `${props.topic}.md`);
  };

  return (
    <>
      <PreviewActions copy={copy} download={download} />
      <div className="markdown-body">
        <pre className={styles["export-content"]}>{mdText}</pre>
      </div>
    </>
  );
}