// Auto-apply: for a while, in one folder the user names, the model's edits, new files, copies and
// builds take effect without a /files apply each time. Without it, a task that changes many files
// stops after every batch to ask, and the user ends up approving the same kind of change again and
// again. Every change is still backed up, logged and reversible with /files undo. Plugin installs
// and other commands always ask. Only the user can turn it on, with a /files command; it ends on
// its own after a set time or a set number of changes.

import * as path from "node:path";
import { apply, pendingList } from "./edits";
import { folderInText, isInside, realPath, samePath, Scope, tooBroad } from "./scope";
import { dataDir, readJson, writeJson } from "./store";

interface Window {
  folder: string;
  until: number;
  used: number;
}

export const MAX_CHANGES = 60;
const DEFAULT_HOURS = 2;
const MAX_HOURS = 12;
// Project commands that only produce build output, so they may run with the edits that need them.
const BUILD_NAME = /^(build|compile|bundle)([:_-].+)?$/i;

const file = () => path.join(dataDir(), "autoapply.json");
const now = () => Date.now();
const active = (): Window[] => readJson<Window[]>(file(), []).filter((w) => w.until > now() && w.used < MAX_CHANGES);

const clock = (ms: number) => new Date(ms).toTimeString().slice(0, 5);

export function autoApplyStatus(): string[] {
  return active().map((w) => `${w.folder} until ${clock(w.until)}, ${MAX_CHANGES - w.used} changes left`);
}

// How long a window lasts: "3h", "90m", "1.5 hours"; the default when none is given.
function duration(text: string): number | { error: string } {
  const t = text.trim();
  if (!t) return DEFAULT_HOURS * 3600_000;
  const m = /^(\d+(?:\.\d+)?)\s*(h|hr|hrs|hours?|m|min|mins|minutes?)\b/i.exec(t);
  if (!m) return { error: `"${t}" is not a length of time. Use, for example, 2h or 30m.` };
  const ms = Number(m[1]) * (/^m/i.test(m[2]) ? 60_000 : 3600_000);
  if (ms < 60_000) return { error: "That is too short." };
  return Math.min(ms, MAX_HOURS * 3600_000);
}

// /files autoapply <folder> [time] | off [folder] | (nothing, to show what is on)
export function autoApplyCommand(scope: Scope, arg: string): string {
  const text = arg.trim();
  if (!text) {
    const on = autoApplyStatus();
    if (on.length) return `Auto-apply is on for:\n${on.map((l) => `  ${l}`).join("\n")}\nSend /files autoapply off to end it.`;
    // With no folder named, the folder the waiting changes are in is the one meant, when there is just one.
    const folders = [...new Set(pendingList().filter((p) => p.kind !== "install" && p.kind !== "run").map((p) => (p.kind === "copy" && p.dest ? p.dest : path.dirname(p.path))))];
    if (folders.length === 1) {
      const waiting = pendingList().map((p) => `#${p.id}`).join(", ");
      return `${autoApplyCommand(scope, folders[0])}\nAlready waiting from before: ${waiting}. Send /files apply to apply them; new changes there apply on their own.`;
    }
    return folders.length
      ? `Auto-apply is off. Changes are waiting in more than one folder, so name one: /files autoapply <folder>.`
      : "Auto-apply is off. Send /files autoapply <folder> to turn it on for that folder for 2 hours, or add a time, such as 4h.";
  }
  const off = /^off\b\s*(.*)$/i.exec(text);
  if (off) {
    const all = readJson<Window[]>(file(), []);
    const named = off[1].trim() ? folderInText(off[1]) : null;
    const left = named ? all.filter((w) => !samePath(w.folder, named.folder)) : [];
    writeJson(file(), left.filter((w) => w.until > now()));
    return named ? `Auto-apply is off for ${named.folder}. Changes there wait for /files apply again.` : "Auto-apply is off. Every change waits for /files apply again.";
  }
  const named = folderInText(text);
  if (!named) return `${text} is not a folder.`;
  const folder = named.folder;
  const r = scope.resolve(folder, "write");
  if ("error" in r) return r.error;
  if (tooBroad(folder)) return `${folder} is too broad. Name the project folder.`;
  const ms = duration(named.extra);
  if (typeof ms !== "number") return ms.error;
  const all = readJson<Window[]>(file(), []).filter((w) => w.until > now() && !samePath(w.folder, folder));
  const until = now() + ms;
  all.push({ folder, until, used: 0 });
  writeJson(file(), all);
  return [
    `Auto-apply is on for ${folder} until ${clock(until)}, for up to ${MAX_CHANGES} changes.`,
    "Edits, new files, copies and builds there take effect without /files apply. Each is backed up and listed by /files status; /files undo reverses the last one.",
    "Plugin installs and other commands still ask. /files autoapply off ends it early.",
  ].join("\n");
}

function windowFor(p: { kind: string; path: string; find?: string }): Window | null {
  if (p.kind === "install") return null;
  if (p.kind === "run" && !BUILD_NAME.test(p.find ?? "")) return null;
  const at = realPath(p.path);
  return active().find((w) => isInside(at, w.folder)) ?? null;
}

// Called with a tool's "status: proposed" result. When auto-apply covers the proposal, applies it
// at once and says so; otherwise returns the result unchanged.
export async function maybeAutoApply(scope: Scope, out: string): Promise<string> {
  if (!out.startsWith("status: proposed")) return out;
  const id = Number(/#(\d+)/.exec(out)?.[1]);
  const p = pendingList().find((x) => x.id === id);
  if (!p) return out;
  const w = windowFor(p);
  if (!w) return out;
  const result = await apply(scope, [id]);
  const all = readJson<Window[]>(file(), []);
  const mine = all.find((x) => samePath(x.folder, w.folder));
  if (mine) mine.used++;
  writeJson(file(), all);
  const made = p.kind === "run" ? /^#\d+ ran /.test(result) : /^#\d+ (applied|copied)/.test(result);
  const passed = p.kind !== "run" || /it succeeded/.test(result);
  const left = Math.max(0, MAX_CHANGES - (mine?.used ?? w.used + 1));
  const window = `Auto-apply is on for ${w.folder} until ${clock(w.until)} (${left} changes left)`;
  return [
    !made ? "status: error" : passed ? "status: applied" : "status: failed",
    result,
    !made
      ? "next: The change could not be made. Read the file again and propose it again."
      : passed
        ? `note: ${window}, so this is already done. Carry on with the task; do not ask the user to apply it. The user can reverse the last change with /files undo.`
        : `note: ${window}. The command ran and failed; fix the cause and run it again.`,
  ].join("\n");
}

// Auto-apply: for a while, in one folder the user names, the model's edits, new files, copies and
// builds take effect without a /files apply each time. Without it, a task that changes many files
// stops after every batch to ask, and the user ends up approving the same kind of change again and
// again. Every change is still backed up, logged and reversible with /files undo. Plugin installs
// and other commands always ask. Only the user can turn it on, with a /files command; it ends on
// its own after a set time or a set number of changes.

import * as path from "node:path";
import { apply, pendingList } from "./edits";
import { folderInText, isInside, realPath, samePath, Scope, tooBroad } from "./scope";
import { dataDir, readJson, writeJson } from "./store";

interface Window {
  folder: string;
  until: number;
  used: number;
}

export const MAX_CHANGES = 60;
const DEFAULT_HOURS = 2;
const MAX_HOURS = 12;
// Project commands that only produce build output, so they may run with the edits that need them.
const BUILD_NAME = /^(build|compile|bundle)([:_-].+)?$/i;

const file = () => path.join(dataDir(), "autoapply.json");
const now = () => Date.now();
const active = (): Window[] => readJson<Window[]>(file(), []).filter((w) => w.until > now() && w.used < MAX_CHANGES);

const clock = (ms: number) => new Date(ms).toTimeString().slice(0, 5);

export function autoApplyStatus(): string[] {
  return active().map((w) => `${w.folder} until ${clock(w.until)}, ${MAX_CHANGES - w.used} changes left`);
}

// How long a window lasts: "3h", "90m", "1.5 hours"; the default when none is given.
function duration(text: string): number | { error: string } {
  const t = text.trim();
  if (!t) return DEFAULT_HOURS * 3600_000;
  const m = /^(\d+(?:\.\d+)?)\s*(h|hr|hrs|hours?|m|min|mins|minutes?)\b/i.exec(t);
  if (!m) return { error: `"${t}" is not a length of time. Use, for example, 2h or 30m.` };
  const ms = Number(m[1]) * (/^m/i.test(m[2]) ? 60_000 : 3600_000);
  if (ms < 60_000) return { error: "That is too short." };
  return Math.min(ms, MAX_HOURS * 3600_000);
}

// /files autoapply <folder> [time] | off [folder] | (nothing, to show what is on)
export function autoApplyCommand(scope: Scope, arg: string): string {
  const text = arg.trim();
  if (!text) {
    const on = autoApplyStatus();
    if (on.length) return `Auto-apply is on for:\n${on.map((l) => `  ${l}`).join("\n")}\nSend /files autoapply off to end it.`;
    // With no folder named, the folder the waiting changes are in is the one meant, when there is just one.
    const folders = [...new Set(pendingList().filter((p) => p.kind !== "install" && p.kind !== "run").map((p) => (p.kind === "copy" && p.dest ? p.dest : path.dirname(p.path))))];
    if (folders.length === 1) {
      const waiting = pendingList().map((p) => `#${p.id}`).join(", ");
      return `${autoApplyCommand(scope, folders[0])}\nAlready waiting from before: ${waiting}. Send /files apply to apply them; new changes there apply on their own.`;
    }
    return folders.length
      ? `Auto-apply is off. Changes are waiting in more than one folder, so name one: /files autoapply <folder>.`
      : "Auto-apply is off. Send /files autoapply <folder> to turn it on for that folder for 2 hours, or add a time, such as 4h.";
  }
  const off = /^off\b\s*(.*)$/i.exec(text);
  if (off) {
    const all = readJson<Window[]>(file(), []);
    const named = off[1].trim() ? folderInText(off[1]) : null;
    const left = named ? all.filter((w) => !samePath(w.folder, named.folder)) : [];
    writeJson(file(), left.filter((w) => w.until > now()));
    return named ? `Auto-apply is off for ${named.folder}. Changes there wait for /files apply again.` : "Auto-apply is off. Every change waits for /files apply again.";
  }
  const named = folderInText(text);
  if (!named) return `${text} is not a folder.`;
  const folder = named.folder;
  const r = scope.resolve(folder, "write");
  if ("error" in r) return r.error;
  if (tooBroad(folder)) return `${folder} is too broad. Name the project folder.`;
  const ms = duration(named.extra);
  if (typeof ms !== "number") return ms.error;
  const all = readJson<Window[]>(file(), []).filter((w) => w.until > now() && !samePath(w.folder, folder));
  const until = now() + ms;
  all.push({ folder, until, used: 0 });
  writeJson(file(), all);
  return [
    `Auto-apply is on for ${folder} until ${clock(until)}, for up to ${MAX_CHANGES} changes.`,
    "Edits, new files, copies and builds there take effect without /files apply. Each is backed up and listed by /files status; /files undo reverses the last one.",
    "Plugin installs and other commands still ask. /files autoapply off ends it early.",
  ].join("\n");
}

function windowFor(p: { kind: string; path: string; find?: string }): Window | null {
  if (p.kind === "install") return null;
  if (p.kind === "run" && !BUILD_NAME.test(p.find ?? "")) return null;
  const at = realPath(p.path);
  return active().find((w) => isInside(at, w.folder)) ?? null;
}

// Called with a tool's "status: proposed" result. When auto-apply covers the proposal, applies it
// at once and says so; otherwise returns the result unchanged.
export async function maybeAutoApply(scope: Scope, out: string): Promise<string> {
  if (!out.startsWith("status: proposed")) return out;
  const id = Number(/#(\d+)/.exec(out)?.[1]);
  const p = pendingList().find((x) => x.id === id);
  if (!p) return out;
  const w = windowFor(p);
  if (!w) return out;
  const result = await apply(scope, [id]);
  const all = readJson<Window[]>(file(), []);
  const mine = all.find((x) => samePath(x.folder, w.folder));
  if (mine) mine.used++;
  writeJson(file(), all);
  const made = p.kind === "run" ? /^#\d+ ran /.test(result) : /^#\d+ (applied|copied)/.test(result);
  const passed = p.kind !== "run" || /it succeeded/.test(result);
  const left = Math.max(0, MAX_CHANGES - (mine?.used ?? w.used + 1));
  const window = `Auto-apply is on for ${w.folder} until ${clock(w.until)} (${left} changes left)`;
  return [
    !made ? "status: error" : passed ? "status: applied" : "status: failed",
    result,
    !made
      ? "next: The change could not be made. Read the file again and propose it again."
      : passed
        ? `note: ${window}, so this is already done. Carry on with the task; do not ask the user to apply it. The user can reverse the last change with /files undo.`
        : `note: ${window}. The command ran and failed; fix the cause and run it again.`,
  ].join("\n");
}