/**
 * Clean Command
 *
 * Removes the .gitnexus index from the current repository.
 * Also unregisters it from the global registry.
 */

import fs from 'fs/promises';
import path from 'path';
import { logger } from '../core/logger.js';
import {
  findRegistryEntryByRepoPath,
  findRepo,
  unregisterRepo,
  listRegisteredRepos,
  getStoragePaths,
  type RegistryEntry,
} from '../storage/repo-manager.js';
import { requireDeletableStoragePath, StorageDeletionError } from '../storage/storage-resolver.js';
import { formatSlotSize, formatStaleSlotLine } from './stale-branch-format.js';
import { listLocalHeads } from '../storage/git.js';
import {
  isContainedBranchDir,
  isDeleteCandidate,
  listStaleBranchSlots,
  removeBranchSlot,
  staleListingBlock,
  type StaleBranchSlot,
} from '../storage/stale-branch-slots.js';
import {
  cleanParkedLbugSidecars,
  inspectLbugSidecars,
  listParkedLbugSidecars,
} from '../core/lbug/sidecar-recovery.js';
import { t } from './i18n/index.js';
import { getGlobalDir } from '../storage/global-dir.js';
import { STORES_DIR } from '../storage/shared-store.js';
import {
  findLegacyLocalIndex,
  reclaimAfterSlotRemoval,
  reclaimSharedStore,
  removeLegacyLocalIndex,
  removeSharedStorePointer,
  withCheckoutSlotLock,
  type ReclaimResult,
} from '../storage/shared-store-lifecycle.js';

type OwnedCwdStorage = {
  repo: NonNullable<Awaited<ReturnType<typeof findRepo>>>;
  entry: RegistryEntry | undefined;
  storagePath: string;
};

const resolveOwnedCwdStorage = async (refusePrefix: string): Promise<OwnedCwdStorage | null> => {
  const repo = await findRepo(process.cwd());
  if (!repo) {
    console.log(t('clean.notFoundHere'));
    return null;
  }
  try {
    const [entries, storagePath] = await Promise.all([
      listRegisteredRepos(),
      requireDeletableStoragePath({
        path: repo.repoPath,
        storagePath: repo.storagePath,
      }),
    ]);
    return {
      repo,
      entry: findRegistryEntryByRepoPath(entries, repo.repoPath),
      storagePath,
    };
  } catch (err) {
    if (err instanceof StorageDeletionError) {
      logger.error(`${refusePrefix}${err.message}`);
      return null;
    }
    throw err;
  }
};

const printStaleSlotLines = (message: string, slots: readonly StaleBranchSlot[]): void => {
  console.log(message);
  for (const slot of slots) {
    console.log(`  - ${formatStaleSlotLine(slot)}`);
  }
};

const cleanStaleBranchSlots = async (force: boolean): Promise<void> => {
  const owned = await resolveOwnedCwdStorage('Refusing to clean leftover branch indexes: ');
  if (!owned) return;
  const { repo, entry, storagePath } = owned;
  const slots = await listStaleBranchSlots({
    repoPath: repo.repoPath,
    storagePath,
    branches: entry?.branches,
    includeSize: !force,
  });
  const listingBlock = staleListingBlock(slots);
  if (listingBlock === 'heads-unavailable') {
    printStaleSlotLines(
      t('clean.stale.headsUnavailable'),
      slots.filter((row) => row.reason === 'heads-unavailable'),
    );
    return;
  }
  if (listingBlock === 'listing-failed') {
    console.log(t('clean.stale.listingFailed'));
    return;
  }
  const candidates = slots.filter(isDeleteCandidate);
  const probeFailed = slots.filter((slot) => slot.reason === 'probe-failed');
  if (candidates.length === 0) {
    if (probeFailed.length > 0) {
      printStaleSlotLines(t('clean.stale.probeFailed'), probeFailed);
      return;
    }
    console.log(t('clean.stale.none'));
    return;
  }
  if (!force) {
    printStaleSlotLines(t('clean.stale.preview', { count: candidates.length }), candidates);
    if (probeFailed.length > 0) {
      printStaleSlotLines(t('clean.stale.probeFailed'), probeFailed);
    }
    console.log(`\n${t('common.runForceConfirm')}`);
    return;
  }
  let deletedAny = false;
  for (const slot of candidates) {
    const heads = listLocalHeads(repo.repoPath);
    if (heads === null) {
      console.log(
        deletedAny ? t('clean.stale.remainingSkipped') : t('clean.stale.headsUnavailable'),
      );
      return;
    }
    if (heads.includes(slot.branch)) {
      console.log(t('clean.stale.skippedLive', { branch: slot.branch }));
      continue;
    }
    const result = await removeBranchSlot({
      repoPath: repo.repoPath,
      storagePath,
      branch: slot.branch,
      dir: slot.dir,
    });
    if (!result.ok) {
      console.log(t('clean.stale.failed', { branch: slot.branch }));
      logger.error({ err: result.error }, 'Failed to delete leftover branch index:');
      continue;
    }
    deletedAny = true;
    console.log(t('clean.stale.deleted', { branch: slot.branch }));
  }
  if (probeFailed.length > 0) {
    printStaleSlotLines(t('clean.stale.probeFailed'), probeFailed);
  }
};

const reportReclaim = (result: ReclaimResult | null): void => {
  if (!result) return;
  if (result.removed.length > 0) {
    console.log(t('clean.shared.reclaimed', { count: result.removed.length }));
  }
  if (result.kept.length > 0) console.log(t('clean.shared.kept', { count: result.kept.length }));
};

/** `clean --gc`: collect every shared store under GITNEXUS_HOME (#3352). */
const collectSharedStores = async (force: boolean): Promise<void> => {
  const storesDir = path.join(getGlobalDir(), STORES_DIR);
  // Only a missing stores root means "nothing to collect"; an unreadable one
  // must fail loudly rather than report success.
  const names = await fs.readdir(storesDir).catch((err: NodeJS.ErrnoException) => {
    if (err.code === 'ENOENT') return [] as string[];
    throw err;
  });
  if (names.length === 0) {
    console.log(t('clean.gc.none'));
    return;
  }
  for (const name of names) {
    const root = path.join(storesDir, name);
    // Stray files (`.DS_Store`) are not stores.
    if (!(await fs.stat(root)).isDirectory()) continue;
    // Without --force this is a preview: same selection, nothing deleted.
    const result = await reclaimSharedStore(root, { gc: true, dryRun: !force });
    console.log(
      t(force ? 'clean.gc.store' : 'clean.gc.preview', {
        path: root,
        members: result.droppedMembers.length,
        graphs: result.removed.length,
      }),
    );
    if (result.kept.length > 0) console.log(t('clean.shared.kept', { count: result.kept.length }));
    if (result.storeRemoved) console.log(t('clean.shared.storeRemoved', { path: root }));
  }
  if (!force) console.log(`\n${t('common.runForceConfirm')}`);
};

export const cleanCommand = async (options?: {
  force?: boolean;
  all?: boolean;
  lbugSidecars?: boolean;
  stale?: boolean;
  branch?: string;
  gc?: boolean;
  localIndex?: boolean;
}) => {
  if (options?.gc) {
    await collectSharedStores(options.force === true);
    return;
  }

  // --local-index: delete a pre-adoption index left in <checkout>/.gitnexus
  // after the checkout moved into a shared store (#3352). Keeps the pointer.
  if (options?.localIndex) {
    const repo = await findRepo(process.cwd());
    if (!repo) {
      console.log(t('clean.notFoundHere'));
      return;
    }
    const legacy = await findLegacyLocalIndex(repo.repoPath, repo.storagePath);
    if (!legacy) {
      console.log(t('clean.localIndex.none'));
      return;
    }
    if (!options.force) {
      console.log(
        t('clean.localIndex.preview', { path: legacy.dir, size: formatSlotSize(legacy.bytes) }),
      );
      console.log(`\n${t('common.runForceConfirm')}`);
      return;
    }
    await removeLegacyLocalIndex(repo.repoPath, repo.storagePath);
    console.log(
      t('clean.localIndex.deleted', { path: legacy.dir, size: formatSlotSize(legacy.bytes) }),
    );
    return;
  }

  // --stale: reclaim leftover per-branch slots whose recorded branch is not
  // a live local head (#3331). Exclusive arm before --branch.
  if (options?.stale) {
    await cleanStaleBranchSlots(options.force === true);
    return;
  }

  // --branch <name>: remove a single non-primary branch's index (#2106 R7).
  // Resolve against the RECORDED branches[] summary (never by slugging the
  // user's raw input, which can disagree with the index-time-sanitized label).
  if (options?.branch) {
    const owned = await resolveOwnedCwdStorage('Refusing to clean branch index: ');
    if (!owned) return;
    const { repo, entry, storagePath } = owned;
    const summary = entry?.branches?.find((b) => b.branch === options.branch);
    if (!summary) {
      console.log(t('clean.branchNotIndexed', { branch: options.branch }));
      return;
    }
    const { lbugPath } = getStoragePaths(repo.repoPath, summary.branch, storagePath);
    const branchDir = path.dirname(lbugPath);
    if (!isContainedBranchDir(storagePath, branchDir)) {
      logger.error(
        `Refusing to clean branch index outside the validated storage slot: ${branchDir}`,
      );
      return;
    }
    if (!options.force) {
      console.log(t('clean.deleteBranch', { branch: summary.branch, path: branchDir }));
      console.log(`\n${t('common.runForceConfirm')}`);
      return;
    }
    const result = await removeBranchSlot({
      repoPath: repo.repoPath,
      storagePath,
      branch: summary.branch,
      dir: branchDir,
    });
    if (!result.ok) {
      logger.error({ err: result.error }, 'Failed to delete branch index:');
      return;
    }
    console.log(t('clean.deletedBranch', { branch: summary.branch }));
    return;
  }

  if (options?.lbugSidecars) {
    const cwd = process.cwd();
    const repo = await findRepo(cwd);

    if (!repo) {
      console.log(t('clean.notFoundHere'));
      return;
    }

    let storagePath: string;
    try {
      storagePath = await requireDeletableStoragePath({
        path: repo.repoPath,
        storagePath: repo.storagePath,
      });
    } catch (err) {
      if (err instanceof StorageDeletionError) {
        logger.error(`Refusing to clean sidecars: ${err.message}`);
        return;
      }
      throw err;
    }
    const { lbugPath } = getStoragePaths(repo.repoPath, undefined, storagePath);
    const state = await inspectLbugSidecars(lbugPath);
    // Single roster authority (this shipping review, FIX 5): the aggregate
    // covers both parked-sidecar families — the timestamped missing-shadow
    // WAL quarantines AND the fixed-name `.dirty-recovery` parks (`.next`
    // residues included) left by a dirty-flag recovery rebuild (#2409). The
    // previous inline concatenations here were how the `.next` residue
    // stayed invisible to this surface.
    const quarantined = await listParkedLbugSidecars(lbugPath);

    console.log(t('clean.lbugSidecars.state', { state: state.kind }));
    if (quarantined.length === 0) {
      console.log(t('clean.lbugSidecars.none'));
      return;
    }

    if (!options.force) {
      console.log(t('clean.lbugSidecars.preview', { count: quarantined.length }));
      for (const file of quarantined) {
        console.log(`  - ${file}`);
      }
      console.log(`\n${t('common.runForceConfirm')}`);
      return;
    }

    const { deleted, failed } = await cleanParkedLbugSidecars(lbugPath);
    console.log(t('clean.lbugSidecars.deleted', { count: deleted.length }));
    // A locked parked file no longer crashes the clean mid-command (FIX 5)
    // — the rest were deleted above; report what remains and why.
    if (failed.length > 0) {
      console.log(t('clean.lbugSidecars.failed', { count: failed.length }));
      for (const file of failed) {
        console.log(`  - ${file}`);
      }
    }
    return;
  }

  // --all flag: clean all indexed repos
  if (options?.all) {
    const entries = await listRegisteredRepos();
    if (!options?.force) {
      const deletableEntries = [];
      for (const entry of entries) {
        try {
          await requireDeletableStoragePath(entry);
          deletableEntries.push(entry);
        } catch (err) {
          if (err instanceof StorageDeletionError) {
            logger.error(`Refusing to preview ${entry.name}: ${err.message}`);
            continue;
          }
          throw err;
        }
      }
      if (deletableEntries.length === 0) {
        console.log(t('common.notIndexed'));
        return;
      }
      console.log(t('clean.deleteAll', { count: deletableEntries.length }));
      for (const entry of deletableEntries) {
        console.log(`  - ${entry.name} (${entry.path})`);
      }
      console.log(`\n${t('common.runForceConfirm')}`);
      return;
    }

    for (const entry of entries) {
      try {
        const storagePath = await requireDeletableStoragePath(entry);
        await withCheckoutSlotLock(storagePath, async () => {
          await fs.rm(storagePath, { recursive: true, force: true });
          await unregisterRepo(entry.path);
        });
        console.log(t('clean.deletedRepo', { name: entry.name, storagePath }));
        const reclaim = await reclaimAfterSlotRemoval(storagePath);
        if (reclaim) await removeSharedStorePointer(entry.path);
        reportReclaim(reclaim);
      } catch (err) {
        if (err instanceof StorageDeletionError) {
          logger.error(`Refusing to clean ${entry.name}: ${err.message}`);
          continue;
        }
        logger.error({ err }, `Failed to delete ${entry.name}:`);
      }
    }
    return;
  }

  // Default: clean current repo
  const cwd = process.cwd();
  const repo = await findRepo(cwd);

  if (!repo) {
    console.log(t('clean.notFoundHere'));
    return;
  }

  const repoName = repo.repoPath.split(/[/\\]/).pop() || repo.repoPath;
  let storagePath: string;
  try {
    storagePath = await requireDeletableStoragePath({
      path: repo.repoPath,
      storagePath: repo.storagePath,
    });
  } catch (err) {
    if (err instanceof StorageDeletionError) {
      logger.error(`Refusing to clean ${repoName}: ${err.message}`);
      return;
    }
    throw err;
  }

  if (!options?.force) {
    console.log(t('clean.deleteCurrent', { repoName }));
    console.log(`   ${t('common.path')}: ${storagePath}`);
    console.log(`\n${t('common.runForceConfirm')}`);
    return;
  }

  try {
    await withCheckoutSlotLock(storagePath, async () => {
      await fs.rm(storagePath, { recursive: true, force: true });
      await unregisterRepo(repo.repoPath);
    });
    console.log(t('common.deleted', { target: storagePath }));
    const reclaim = await reclaimAfterSlotRemoval(storagePath);
    if (reclaim) await removeSharedStorePointer(repo.repoPath);
    reportReclaim(reclaim);
  } catch (err) {
    logger.error({ err }, 'Failed to delete:');
  }
};