import type { NamingEntityInput } from "../naming/variables.ts";
import { DEFAULT_TEMPLATES, type NamingTemplateSet, renderMediaFileName } from "../path/binding.ts";
import { buildNamingContext } from "../path/template.ts";
import { type ParseOptions, parseReleasePath } from "../release-parser/index.ts";
import { fileKindOf } from "../release-parser/parse.ts";
import type { ParsedRelease } from "../release-parser/types.ts";
import {
  basename,
  type DefaultSubtitleLang,
  dirname,
  sidecarLanguageSuffix,
  sidecarStem,
  splitExt,
} from "./sidecars.ts";

export type OrganizeOperation = "copy" | "move" | "rename" | "in_place";
export type OrganizeFileKind = "video" | "subtitle" | "audio" | "nfo" | "other";
export type ExistingPolicy = "skip" | "replace_with_verify" | "conflict";

export interface SourceFile {
  path: string;
  size: number;
  /** 设备号(stat.dev),由调用方提供;未知则不判断跨卷 */
  device?: string | number;
  /** qB 文件清单下标 */
  index?: number;
  sha256?: string;
}

export interface ExistingTarget {
  path: string;
  size: number;
  sha256?: string;
}

export interface OrganizeInput {
  operation: OrganizeOperation;
  mediaType: "movie" | "tv";
  /** 种子内容根(整季包目录);只在它之内取父目录名参与解析 */
  sourceRoot?: string;
  files: readonly SourceFile[];
  /** 本地实体的命名信息(不用发布标题命名;可带英文名/外部 ID/季集元数据等命名变量来源) */
  entity: NamingEntityInput;
  /** 目标目录(宿主绝对路径,来自 path.resolveTargetDirectory + 库根) */
  target: { movieDir?: string; seasonDirs?: Record<number, string>; device?: string | number };
  templates?: NamingTemplateSet;
  existingTargets?: readonly ExistingTarget[];
  /** 目标已存在时的策略,默认 conflict(待处理) */
  onExisting?: ExistingPolicy;
  /** H&R/做种保留是否已满足;move 必需 */
  retention?: { hnrSatisfied: boolean | "unknown" };
  /** 主视频最小体积,默认 50 MiB;低于此值视为样例/垃圾 */
  minVideoBytes?: number;
  grants?: { replace?: boolean };
  /** Explicit one-time replacement grants, restricted to the selected old library paths. */
  replacePaths?: readonly string[];
  parse?: ParseOptions;
  /** 随行字幕里此语言加 .default 标记(对照 MP DEFAULT_SUB);不设不加 */
  defaultSubtitleLang?: DefaultSubtitleLang;
  /**
   * 逐文件季/集覆写(人工确认,优先于文件名解析):键为源文件路径或其所在目录(最长前缀生效)。
   * 只影响剧集的季目录选择与命名;电影忽略。
   */
  overrides?: Readonly<Record<string, FileOverride>>;
}

export interface FileOverride {
  season?: number;
  episodes?: { start: number; end: number };
  /**
   * 不入库(调用方按作品集数映射判定:集数待确认 episode_unresolved、映射规则标为特别篇 / 花絮 / 忽略 special_extra);
   * 只按精确路径生效,目录前缀覆写不带它
   */
  exclude?: { reason: "episode_unresolved" | "special_extra"; detail?: string };
}

/** 源路径的覆写:精确命中优先,否则取最长的目录前缀 */
export function overrideFor<T extends FileOverride>(
  overrides: Readonly<Record<string, T>> | undefined,
  path: string,
): T | undefined {
  if (!overrides) return undefined;
  const exact = overrides[path];
  if (exact) return exact;
  let best: { len: number; o: T } | undefined;
  for (const [k, o] of Object.entries(overrides)) {
    const dir = k.replace(/\/+$/, "");
    if (path.startsWith(`${dir}/`) && (!best || dir.length > best.len)) best = { len: dir.length, o };
  }
  return best?.o;
}

export type PlannedAction = "transfer" | "replace" | "skip" | "hold";

export interface PlannedFile {
  src: string;
  dst: string;
  size: number;
  kind: OrganizeFileKind;
  role: "main" | "sidecar";
  mainSrc?: string;
  /** 跨卷:执行层必须走 copy → verify → delete source,EXDEV 不得静默降级 */
  crossDevice?: boolean;
  action: PlannedAction;
  skipReason?: "already_in_library" | "target_exists" | "main_not_transferred";
  season?: number;
  episodes?: { start: number; end: number };
  airDate?: string;
}

export interface ExcludedFile {
  src: string;
  kind: OrganizeFileKind;
  reason:
    | "sample"
    | "too_small"
    | "not_imported_kind"
    | "orphan_sidecar"
    | "no_episode"
    | "episode_unresolved"
    | "special_extra"
    | "extra_content"
    | "no_target_dir"
    | "naming_failed";
  detail?: string;
}

export interface OrganizeConflict {
  kind:
    | "target_exists"
    | "duplicate_target"
    | "replace_requires_grant"
    | "hnr_unsatisfied"
    | "hnr_unknown"
    | "orphan_sidecar"
    | "no_main_video";
  /** 阻塞 = 需要审批/授权后才能执行 */
  blocking: boolean;
  src?: string;
  dst?: string;
  detail?: string;
}

export type Precondition =
  | { kind: "free_space"; device?: string | number; bytes: number }
  | { kind: "target_absent"; paths: string[] }
  | { kind: "source_unchanged"; files: { path: string; size: number }[] }
  | { kind: "verify_after_copy"; paths: string[] }
  | { kind: "hnr_satisfied" }
  | { kind: "quarantine_replaced"; paths: string[] };

export interface OrganizePlan {
  operation: OrganizeOperation;
  crossDevice: boolean;
  files: PlannedFile[];
  excluded: ExcludedFile[];
  preconditions: Precondition[];
  conflicts: OrganizeConflict[];
  requiresApproval: boolean;
}

const SAMPLE_RE = /(?:^|[.\-_ [(])sample(?:[.\-_ \])]|$)/i;
const SPECIAL_RE =
  /(?:^|[.\-_ [])(?:NC)?(?:OP|ED|PV|CM|MENU|TRAILER|TEASER|SP|OVA|OAD|NCOP|NCED)\d{0,2}(?:[.\-_ \]]|$)/i;

function kindOf(path: string): OrganizeFileKind {
  const k = fileKindOf(path);
  if (k === "video" || k === "subtitle" || k === "audio" || k === "nfo") return k;
  return "other";
}

function segmentsFor(
  path: string,
  sourceRoot?: string,
): { file: string; parent?: string; grandParent?: string } | string {
  if (!sourceRoot) return path;
  const root = sourceRoot.replace(/\\/g, "/").replace(/\/+$/, "");
  const p = path.replace(/\\/g, "/");
  if (p !== root && !p.startsWith(`${root}/`)) return path;
  const within = [basename(root), ...p.slice(root.length + 1).split("/")].filter(Boolean);
  const file = within.pop() ?? basename(p);
  if (file === basename(root) && within.length === 0) return { file };
  const parent = within.pop();
  const grandParent = within.pop();
  return {
    file,
    ...(parent !== undefined ? { parent } : {}),
    ...(grandParent !== undefined ? { grandParent } : {}),
  };
}

const sameDevice = (a?: string | number, b?: string | number) =>
  a === undefined || b === undefined ? undefined : String(a) !== String(b);

/**
 * 整理计划(纯逻辑,不做 IO):选择主视频与随行附属文件、排除样例、计算目标、
 * 目标存在策略、跨卷标记、H&R 前置条件。结果交给执行层冻结并按步骤执行。
 */
export function planOrganize(input: OrganizeInput): OrganizePlan {
  const templates = input.templates ?? DEFAULT_TEMPLATES;
  const minVideo = input.minVideoBytes ?? 50 * 1024 * 1024;
  const onExisting = input.onExisting ?? "conflict";
  const excluded: ExcludedFile[] = [];
  const conflicts: OrganizeConflict[] = [];
  const planned: PlannedFile[] = [];
  const existing = new Map((input.existingTargets ?? []).map((e) => [e.path, e]));
  const targetDevice = input.target.device;
  const isRename = input.operation === "rename";
  const inPlace = input.operation === "in_place";

  const videos: { f: SourceFile; parsed: ParsedRelease; dst: string }[] = [];
  const sidecars: SourceFile[] = [];

  for (const f of input.files) {
    const kind = kindOf(f.path);
    if (kind === "subtitle" || kind === "audio") {
      sidecars.push(f);
      continue;
    }
    if (kind !== "video") {
      excluded.push({ src: f.path, kind, reason: "not_imported_kind" });
      continue;
    }
    const segs = f.path.replace(/\\/g, "/").split("/");
    if (SAMPLE_RE.test(basename(f.path)) || segs.some((s) => /^samples?$/i.test(s))) {
      excluded.push({ src: f.path, kind, reason: "sample" });
      continue;
    }
    if (f.size < minVideo) {
      excluded.push({ src: f.path, kind, reason: "too_small", detail: String(f.size) });
      continue;
    }
    const parsed = parseReleasePath(segmentsFor(f.path, input.sourceRoot), input.parse ?? {});
    const ov = input.mediaType === "tv" ? overrideFor(input.overrides, f.path) : undefined;
    const ex = input.mediaType === "tv" ? input.overrides?.[f.path]?.exclude : undefined;
    if (ex) {
      excluded.push({ src: f.path, kind, reason: ex.reason, ...(ex.detail ? { detail: ex.detail } : {}) });
      continue;
    }
    if (ov?.season !== undefined) parsed.season = ov.season;
    if (ov?.episodes) {
      parsed.episodes = ov.episodes;
      delete parsed.airDate;
    }
    if (parsed.contentType === "extra" && parsed.evidence.includes("dir:extras")) {
      excluded.push({ src: f.path, kind, reason: "extra_content" });
      continue;
    }
    if (inPlace) {
      if (input.mediaType === "tv" && !parsed.episodes && !parsed.airDate) {
        excluded.push({ src: f.path, kind, reason: "no_episode" });
        continue;
      }
      if (input.mediaType === "tv" && parsed.season === undefined) parsed.season = 1;
      videos.push({ f, parsed, dst: f.path });
      continue;
    }
    const [, ext] = splitExt(basename(f.path));
    let dir: string | undefined;
    let named: ReturnType<typeof renderMediaFileName>;
    if (input.mediaType === "movie") {
      dir = input.target.movieDir;
      named = renderMediaFileName("movie", templates, buildNamingContext(input.entity, parsed), ext);
    } else {
      if (!parsed.episodes && !parsed.airDate) {
        const special = SPECIAL_RE.test(splitExt(basename(f.path))[0]);
        excluded.push({ src: f.path, kind, reason: special ? "special_extra" : "no_episode" });
        continue;
      }
      const seasonDirs = input.target.seasonDirs ?? {};
      let season = parsed.season;
      const keys = Object.keys(seasonDirs).map(Number);
      if (season === undefined && keys.length === 1) season = keys[0];
      dir = season !== undefined ? seasonDirs[season] : undefined;
      const ctx = buildNamingContext(input.entity, { ...parsed, ...(season !== undefined ? { season } : {}) });
      named = renderMediaFileName("tv", templates, ctx, ext);
      parsed.season = season;
    }
    if (!dir) {
      excluded.push({ src: f.path, kind, reason: "no_target_dir", detail: `season=${parsed.season ?? "?"}` });
      continue;
    }
    if (!named.ok) {
      excluded.push({ src: f.path, kind, reason: "naming_failed", detail: named.missing.join(",") });
      continue;
    }
    videos.push({ f, parsed, dst: `${dir.replace(/\/+$/, "")}/${named.fileName}` });
  }

  if (videos.length === 0 && input.files.length > 0)
    conflicts.push({ kind: "no_main_video", blocking: true, detail: "没有可入库的主视频" });

  // 主视频
  for (const v of videos) {
    planned.push({
      src: v.f.path,
      dst: v.dst,
      size: v.f.size,
      kind: "video",
      role: "main",
      action: "transfer",
      ...(!inPlace && sameDevice(v.f.device, targetDevice) !== undefined
        ? { crossDevice: sameDevice(v.f.device, targetDevice) }
        : {}),
      ...(v.parsed.season !== undefined ? { season: v.parsed.season } : {}),
      ...(v.parsed.episodes ? { episodes: v.parsed.episodes } : {}),
      ...(v.parsed.airDate ? { airDate: v.parsed.airDate } : {}),
    });
  }

  // 附属文件:同目录、主干名唯一匹配才随行;否则孤儿,不搬不删
  const mainByDirStem = new Map<string, { f: SourceFile; dst: string }[]>();
  for (const v of videos) {
    const key = `${dirname(v.f.path)}\u0000${splitExt(basename(v.f.path))[0].toLowerCase()}`;
    mainByDirStem.set(key, [...(mainByDirStem.get(key) ?? []), { f: v.f, dst: v.dst }]);
  }
  const usedSidecarDst = new Set<string>();
  for (const s of sidecars) {
    const kind = kindOf(s.path);
    const { stem, tags } = sidecarStem(s.path);
    const mains = mainByDirStem.get(`${dirname(s.path)}\u0000${stem}`) ?? [];
    if (mains.length !== 1) {
      excluded.push({
        src: s.path,
        kind,
        reason: "orphan_sidecar",
        detail: mains.length > 1 ? "ambiguous" : "no_match",
      });
      conflicts.push({ kind: "orphan_sidecar", blocking: false, src: s.path });
      continue;
    }
    const main = mains[0]!;
    const [mainStem] = splitExt(main.dst);
    const [, ext] = splitExt(basename(s.path));
    const suffix = sidecarLanguageSuffix(tags, input.defaultSubtitleLang);
    let dst = inPlace ? s.path : `${mainStem}${suffix}.${ext.toLowerCase()}`;
    for (let n = 1; usedSidecarDst.has(dst); n++) dst = `${mainStem}${suffix}.${n}.${ext.toLowerCase()}`;
    usedSidecarDst.add(dst);
    planned.push({
      src: s.path,
      dst,
      size: s.size,
      kind,
      role: "sidecar",
      mainSrc: main.f.path,
      action: "transfer",
      ...(!inPlace && sameDevice(s.device, targetDevice) !== undefined
        ? { crossDevice: sameDevice(s.device, targetDevice) }
        : {}),
    });
  }

  // 计划内目标重复
  const byDst = new Map<string, PlannedFile[]>();
  for (const p of planned) byDst.set(p.dst, [...(byDst.get(p.dst) ?? []), p]);
  for (const [dst, ps] of byDst) {
    if (ps.length < 2) continue;
    for (const p of ps) p.action = "hold";
    conflicts.push({ kind: "duplicate_target", blocking: true, dst, detail: ps.map((p) => p.src).join(" | ") });
  }

  // 目标已存在
  const replaced: string[] = [];
  for (const p of planned) {
    if (inPlace || p.action !== "transfer") continue;
    const e = existing.get(p.dst);
    if (!e) continue;
    if (e.size === p.size && e.sha256 !== undefined && e.sha256 === input.files.find((f) => f.path === p.src)?.sha256) {
      p.action = "skip";
      p.skipReason = "already_in_library";
      continue;
    }
    if (onExisting === "skip") {
      p.action = "skip";
      p.skipReason = "target_exists";
      conflicts.push({ kind: "target_exists", blocking: false, src: p.src, dst: p.dst, detail: "skipped" });
    } else if (onExisting === "replace_with_verify" && (!input.replacePaths || input.replacePaths.includes(p.dst))) {
      p.action = "replace";
      replaced.push(p.dst);
      if (!input.grants?.replace)
        conflicts.push({ kind: "replace_requires_grant", blocking: true, src: p.src, dst: p.dst });
    } else {
      p.action = "hold";
      conflicts.push({ kind: "target_exists", blocking: true, src: p.src, dst: p.dst });
    }
  }
  // 主视频不搬时附属文件也不单独搬
  const mainAction = new Map(planned.filter((p) => p.role === "main").map((p) => [p.src, p.action]));
  for (const p of planned) {
    if (p.role !== "sidecar" || !p.mainSrc) continue;
    const ma = mainAction.get(p.mainSrc);
    if ((ma === "skip" || ma === "hold") && p.action === "transfer") {
      p.action = ma;
      if (ma === "skip") p.skipReason = "main_not_transferred";
    }
  }

  // Move 的 H&R 前置条件:未满足 → 冲突待处理,不静默改 Copy
  const preconditions: Precondition[] = [];
  if (input.operation === "move") {
    const h = input.retention?.hnrSatisfied;
    if (h === true) preconditions.push({ kind: "hnr_satisfied" });
    else
      conflicts.push({
        kind: h === false ? "hnr_unsatisfied" : "hnr_unknown",
        blocking: true,
        detail: "等待做种义务满足,或经授权改用 copy",
      });
  }

  const active = planned.filter((p) => p.action === "transfer" || p.action === "replace");
  const crossDevice = active.some((p) => p.crossDevice === true);
  const needsCopy = (p: PlannedFile) =>
    input.operation === "copy" || (input.operation === "move" && p.crossDevice !== false) || p.action === "replace";
  if (active.length > 0) {
    if (!isRename) {
      const bytes = active.filter(needsCopy).reduce((s, p) => s + p.size, 0);
      if (bytes > 0)
        preconditions.push({
          kind: "free_space",
          ...(targetDevice !== undefined ? { device: targetDevice } : {}),
          bytes,
        });
    }
    if (!inPlace)
      preconditions.push({
        kind: "target_absent",
        paths: active.filter((p) => p.action === "transfer").map((p) => p.dst),
      });
    preconditions.push({ kind: "source_unchanged", files: active.map((p) => ({ path: p.src, size: p.size })) });
    const verify = active.filter((p) => !isRename && needsCopy(p)).map((p) => p.dst);
    if (verify.length > 0) preconditions.push({ kind: "verify_after_copy", paths: verify });
    if (replaced.length > 0) preconditions.push({ kind: "quarantine_replaced", paths: replaced });
  }

  return {
    operation: input.operation,
    crossDevice,
    files: planned,
    excluded,
    preconditions,
    conflicts,
    requiresApproval: conflicts.some((c) => c.blocking),
  };
}