import { TemplatePicker } from "./TemplatePicker";
import { Icon } from "./Icon";
import { formatSize, imageSrc } from "./FileFigure";
import { uploadFile } from "../api";
import { useEffect, useMemo, useRef, useState } from "react";
import { useAgents, useFetch, useModels } from "../hooks";
import { useT, type Key } from "../i18n";
import type { ImageData, Session } from "../types";
import { ModelSelect } from "./ModelSelect";
import { EffortSelect } from "./Regenerate";
import { VoiceButton } from "./Voice";
import { Markdown } from "./Markdown";
import { confirmDialog, promptDialog, toast } from "../dialogs";

interface Suggestion {
  name: string;
  description: string;
}

const BUILTIN: { name: string; key: Key }[] = [
  { name: "compact", key: "command.compact" },
  { name: "new", key: "command.new" },
];

const MAX_SIDE = 2000;


/** Read an image and downscale it: models don't use more detail, and uploads stay small. */
export async function readImage(file: File): Promise<ImageData> {
  const bitmap = await createImageBitmap(file);
  const scale = Math.min(1, MAX_SIDE / Math.max(bitmap.width, bitmap.height));
  const canvas = document.createElement("canvas");
  canvas.width = Math.round(bitmap.width * scale);
  canvas.height = Math.round(bitmap.height * scale);
  canvas.getContext("2d")!.drawImage(bitmap, 0, 0, canvas.width, canvas.height);
  bitmap.close();
  // PNG keeps screenshots crisp; photos become JPEG.
  const type = file.type === "image/png" && file.size < 1_500_000 ? "image/png" : "image/jpeg";
  const url = canvas.toDataURL(type, 0.85);
  return { media_type: type, data: url.slice(url.indexOf(",") + 1) };
}

export function Composer({
  session,
  busy,
  text,
  setText,
  onSend,
  onAbort,
  onUpdate,
}: {
  session: Session;
  busy: boolean;
  text: string;
  setText: (s: string) => void;
  onSend: (text: string, images: ImageData[], effort?: string) => void;
  onAbort: () => void;
  onUpdate: (patch: Partial<Session>) => void;
}) {
  const t = useT();
  const ref = useRef<HTMLTextAreaElement>(null);
  const [images, setImages] = useState<ImageData[]>([]);
  // Non-image attachments, already uploaded into the project.
  const [files, setFiles] = useState<{ name: string; path: string; size: number }[]>([]);
  const [uploading, setUploading] = useState(0);
  const [active, setActive] = useState(0);
  // Reasoning effort for the next message only ("" = model default).
  const [effort, setEffort] = useState("");
  const [interim, setInterim] = useState("");
  const [picker, setPicker] = useState(false);
  // Rendered Markdown instead of the text field (to check formatting before sending).
  const [preview, setPreview] = useState(false);
  const models = useModels();
  const [prov, ...mid] = session.model.split("/");
  const reasoning = !!models.find((p) => p.provider === prov)?.models.find((m) => m.id === mid.join("/"))?.reasoning;
  // @file mentions: token before the caret and matching files.
  const [mention, setMention] = useState<{ start: number; end: number; q: string }>();
  const [mentionHits, setMentionHits] = useState<{ rel: string; is_dir: boolean }[]>([]);
  const agents = useAgents(session.cwd).filter((a) => a.mode === "primary");
  const cmdData = useFetch<{ commands: Suggestion[] }>(`/commands?cwd=${encodeURIComponent(session.cwd)}`).data;

  // Auto-grow.
  useEffect(() => {
    const el = ref.current;
    if (!el) return;
    el.style.height = "auto";
    el.style.height = `${Math.min(el.scrollHeight, window.innerHeight * 0.4)}px`;
  }, [text]);

  const updateMention = (value: string, caret: number) => {
    const m = value.slice(0, caret).match(/(?:^|\s)@([\w./~+\-]*)$/);
    setMention(m ? { start: caret - m[1].length - 1, end: caret, q: m[1] } : undefined);
  };

  useEffect(() => {
    if (!mention || mention.q.length < 1) {
      setMentionHits([]);
      return;
    }
    let alive = true;
    const timer = setTimeout(() => {
      fetch(`/api/files/search?path=${encodeURIComponent(session.cwd)}&q=${encodeURIComponent(mention.q)}`, { credentials: "same-origin" })
        .then((r) => (r.ok ? r.json() : []))
        .then((hits: { rel: string; is_dir: boolean }[]) => alive && setMentionHits(hits.slice(0, 12)))
        .catch(() => {});
    }, 120);
    return () => {
      alive = false;
      clearTimeout(timer);
    };
  }, [mention?.q, session.cwd]);

  const suggestions = useMemo((): { key: string; label: string; description: string; apply: () => void }[] => {
    if (mention && mentionHits.length) {
      return mentionHits.map((h) => ({
        key: h.rel,
        label: `@${h.rel}${h.is_dir ? "/" : ""}`,
        description: h.is_dir ? t("composer.folder") : "",
        apply: () => {
          const insert = `@${h.rel}${h.is_dir ? "/" : ""} `;
          const next = text.slice(0, mention.start) + insert + text.slice(mention.end);
          setText(next);
          setMention(undefined);
          setMentionHits([]);
          const caret = mention.start + insert.length;
          requestAnimationFrame(() => ref.current?.setSelectionRange(caret, caret));
        },
      }));
    }
    const m = text.match(/^\/(\S*)$/);
    if (!m) return [];
    const all: Suggestion[] = [
      ...BUILTIN.map((b) => ({ name: b.name, description: t(b.key) })),
      ...(cmdData?.commands ?? []),
    ];
    return all
      .filter((c) => c.name.startsWith(m[1]))
      .slice(0, 12)
      .map((c) => ({ key: c.name, label: `/${c.name}`, description: c.description, apply: () => setText(`/${c.name} `) }));
  }, [text, cmdData, t, mention, mentionHits]);

  const send = () => {
    if ((!text.trim() && images.length === 0 && files.length === 0) || uploading > 0) return;
    // Files are referenced by path; the agent reads them with its tools.
    const refs = files.length ? `\n\n${t("composer.attachedFiles")}\n${files.map((f) => `- ${f.path} (${formatSize(f.size)})`).join("\n")}` : "";
    onSend(`${text}${refs}`, images, effort);
    setEffort("");
    setImages([]);
    setFiles([]);
  };

  const onKeyDown = (e: React.KeyboardEvent) => {
    if (suggestions.length > 0) {
      if (e.key === "ArrowDown" || e.key === "ArrowUp") {
        e.preventDefault();
        setActive((a) => (a + (e.key === "ArrowDown" ? 1 : suggestions.length - 1)) % suggestions.length);
        return;
      }
      if (e.key === "Tab" || (e.key === "Enter" && !e.shiftKey)) {
        e.preventDefault();
        suggestions[Math.min(active, suggestions.length - 1)].apply();
        return;
      }
      if (e.key === "Escape") {
        e.preventDefault();
        setMention(undefined);
        setMentionHits([]);
        return;
      }
    }
    // Enter sends on desktop; on touch devices Enter inserts a newline.
    const touch = matchMedia("(pointer: coarse)").matches;
    if (e.key === "Enter" && !e.shiftKey && !touch && !e.nativeEvent.isComposing) {
      e.preventDefault();
      send();
    }
    if (e.key === "Escape" && busy) onAbort();
  };

  const addFiles = async (list: FileList | File[]) => {
    const all = [...list];
    try {
      const imgs = await Promise.all(all.filter((f) => f.type.startsWith("image/")).map(readImage));
      setImages((cur) => [...cur, ...imgs]);
    } catch (e: any) {
      toast(e.message ?? String(e));
    }
    // Everything else is uploaded into the project folder.
    for (const f of all.filter((f) => !f.type.startsWith("image/"))) {
      const stamp = new Date().toISOString().replace(/[-:T]/g, "").slice(0, 14);
      const path = `${session.cwd}/.codecraft/uploads/${stamp}-${f.name.replace(/[\\/]/g, "_")}`;
      setUploading((n) => n + 1);
      try {
        await fetch(`/api/files/create?`, { method: "POST", credentials: "same-origin", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ path: `${session.cwd}/.codecraft`, dir: true }) });
        await fetch(`/api/files/create?`, { method: "POST", credentials: "same-origin", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ path: `${session.cwd}/.codecraft/uploads`, dir: true }) });
        // Keep uploads out of git status without touching the project's .gitignore.
        await fetch(`/api/files/upload?path=${encodeURIComponent(`${session.cwd}/.codecraft/uploads/.gitignore`)}`, { method: "PUT", body: "*\n", credentials: "same-origin" });
        await uploadFile(path, f).catch((e) => {
          throw new Error(`${f.name}: ${e.message}`);
        });
        setFiles((cur) => [...cur, { name: f.name, path, size: f.size }]);
      } catch (e: any) {
        toast(e.message ?? String(e));
      } finally {
        setUploading((n) => n - 1);
      }
    }
  };

  const removeFile = (path: string) => {
    setFiles((cur) => cur.filter((f) => f.path !== path));
    void fetch(`/api/files/delete?path=${encodeURIComponent(path)}`, { method: "DELETE", credentials: "same-origin" });
  };

  return (
    <div className="composer-wrap">
      <div
        className="composer"
        onDragOver={(e) => e.preventDefault()}
        onDrop={(e) => {
          e.preventDefault();
          void addFiles(e.dataTransfer.files);
        }}
      >
        {suggestions.length > 0 && (
          <div className="suggest" role="listbox">
            {suggestions.map((s, i) => (
              <div
                key={s.key}
                role="option"
                aria-selected={i === active}
                className={i === active ? "active" : ""}
                onMouseDown={(e) => {
                  e.preventDefault();
                  s.apply();
                  ref.current?.focus();
                }}
              >
                <span className="name">{s.label}</span>
                <span className="desc">{s.description}</span>
              </div>
            ))}
          </div>
        )}
        {(images.length > 0 || files.length > 0 || uploading > 0) && (
          <div className="attachments">
            {files.map((f) => (
              <div className="att file" key={f.path} title={f.path}>
                <span><Icon name="file" /> {f.name}</span>
                <small>{formatSize(f.size)}</small>
                <button onClick={() => removeFile(f.path)} aria-label={t("common.remove")}>
                  <Icon name="close" />
                </button>
              </div>
            ))}
            {uploading > 0 && (
              <div className="att file">
                <span>{t("composer.uploading", { n: uploading })}</span>
              </div>
            )}
            {images.map((img, i) => (
              <div className="att" key={i}>
                <img src={imageSrc(img)} alt="" />
                <button onClick={() => setImages((cur) => cur.filter((_, j) => j !== i))} aria-label={t("common.remove")}>
                  <Icon name="close" />
                </button>
              </div>
            ))}
          </div>
        )}
        {preview && (
          <div
            className="composer-preview"
            role="button"
            tabIndex={0}
            title={t("composer.previewEdit")}
            onClick={() => (setPreview(false), setTimeout(() => ref.current?.focus(), 0))}
            onKeyDown={(e) => e.key === "Enter" && (setPreview(false), setTimeout(() => ref.current?.focus(), 0))}
          >
            {text.trim() ? <Markdown text={text} breaks /> : <span className="hint">{t("composer.previewEmpty")}</span>}
          </div>
        )}
        <textarea
          style={preview ? { display: "none" } : undefined}
          ref={ref}
          rows={1}
          value={text}
          placeholder={interim ? `${interim} …` : busy ? t("composer.placeholderBusy") : t("composer.placeholder")}
          onChange={(e) => {
            setText(e.target.value);
            setActive(0);
            updateMention(e.target.value, e.target.selectionStart ?? e.target.value.length);
          }}
          onClick={(e) => updateMention(e.currentTarget.value, e.currentTarget.selectionStart ?? 0)}
          onKeyDown={onKeyDown}
          onPaste={(e) => {
            const pasted = [...e.clipboardData.files];
            if (pasted.length > 0) {
              e.preventDefault();
              void addFiles(pasted);
            }
          }}
          aria-label={t("composer.placeholder")}
        />
        <div className="composer-bar">
          <div className="composer-options">
          <select
            className="mode-select"
            value={session.agent}
            onChange={(e) => onUpdate({ agent: e.target.value })}
            aria-label={t("composer.mode")}
            title={agents.find((a) => a.name === session.agent)?.description ?? t("composer.mode")}
          >
            {!agents.some((a) => a.name === session.agent) && <option value={session.agent}>{session.agent}</option>}
            {agents.map((a) => (
              <option key={a.name} value={a.name} title={a.description}>
                {a.name}
              </option>
            ))}
          </select>
          {session.agent === "craft" && (
            <div className="mode-tabs" role="tablist" aria-label={t("craft.mode")} title={t("craft.modeHint")}>
              <button className={session.clean_room !== false ? "active" : ""} onClick={() => onUpdate({ clean_room: true })}>
                {t("craft.cleanRoom")}
              </button>
              <button className={session.clean_room === false ? "active deep" : ""} onClick={() => onUpdate({ clean_room: false })}>
                {t("craft.deep")}
              </button>
            </div>
          )}
          <select
            value={session.permission_mode}
            onChange={(e) => onUpdate({ permission_mode: e.target.value as Session["permission_mode"] })}
            title={t("composer.permissionMode")}
          >
            <option value="auto">{t("permissionMode.auto")}</option>
            <option value="default">{t("permissionMode.default")}</option>
            <option value="accept_edits">{t("permissionMode.accept_edits")}</option>
            <option value="bypass">{t("permissionMode.bypass")}</option>
          </select>
          <ModelSelect value={session.model} onChange={(m) => onUpdate({ model: m })} title={t("composer.model")} />
          {reasoning && <EffortSelect value={effort} onChange={setEffort} compact />}
          <button className="ghost" style={{ padding: "3px 6px" }} onClick={() => setPicker(true)} title={t("templates.title")}>
            <Icon name="template" />
          </button>
          {picker && (
            <TemplatePicker
              onClose={() => setPicker(false)}
              onPick={(x) => {
                setPicker(false);
                setText(text.trim() ? `${text.replace(/\s+$/, "")}\n\n${x}` : x);
                setTimeout(() => ref.current?.focus(), 0);
              }}
            />
          )}
          <button
            className={`ghost ${preview ? "active" : ""}`}
            style={{ padding: "3px 6px" }}
            onClick={() => setPreview(!preview)}
            aria-pressed={preview}
            title={t(preview ? "composer.previewEdit" : "composer.preview")}
          >
            <Icon name={preview ? "edit" : "eye"} />
          </button>
          <VoiceButton onText={(d) => setText(text ? `${text.replace(/\s+$/, "")} ${d}` : d)} onInterim={setInterim} />
          <label className="ghost" style={{ cursor: "pointer", padding: "3px 6px" }} title={t("composer.attach")}>
            <Icon name="clip" />
            <input type="file" multiple hidden onChange={(e) => e.target.files && (addFiles(e.target.files), (e.target.value = ""))} />
          </label>
          </div>
          <div className="composer-actions">
          {busy && (
            <button className="danger" onClick={onAbort} title="Esc">
              <Icon name="stop" /> {t("composer.stop")}
            </button>
          )}
          <button className="primary" onClick={send} disabled={uploading > 0 || (!text.trim() && images.length === 0 && files.length === 0)}>
            {busy ? t("composer.queue") : t("composer.send")}
          </button>
          </div>
        </div>
      </div>
    </div>
  );
}