/**
 * Loads YouTrack-sourced issues into the panel's `Issue` shape — the YouTrack
 * counterpart of the [forge issue loader](vscode/src/forge/issueLoader.ts).
 *
 * Returns `[]` (not an error) when YouTrack isn't configured, so the panel can
 * always call this alongside the forge loader and just merge the results.
 */

import type { ExtensionContext } from 'vscode'
import type { Issue } from '../issues/types'
import type { YouTrackIssue } from './api'
import { workspace } from 'vscode'
import { getYouTrackToken } from '../auth/secrets'
import { latestState } from '../issues/stateComment'
import { issueStateFields } from '../issues/stateFields'
import { getSettings } from '../settings/store'
import { issueHtmlUrl, listIssues } from './api'
import { readImportedIds } from './importStore'

/** Host part of the configured base URL — the SecretStorage token key. */
export function youtrackHost(baseUrl: string): string {
  try {
    return new URL(baseUrl).host
  }
  catch {
    return baseUrl.replace(/^https?:\/\//, '').replace(/\/.*$/, '')
  }
}

/**
 * Offset added to a YouTrack issue's numeric id so its board `number` never
 * collides with a forge issue number (which is the routing key for
 * webview↔extension messages and the `number → IssueRef` map).
 * ponytail: assumes forge issue numbers < 1,000,000 and a single mirrored project
 * (readable ids are unique within one project). Widen / hash if either breaks.
 */
const YOUTRACK_NUMBER_OFFSET = 1_000_000

/** `LXF-12` → `1_000_012`; falls back to the offset when there's no numeric tail. */
function syntheticNumber(idReadable: string): number {
  const m = idReadable.match(/-(\d+)$/)
  return YOUTRACK_NUMBER_OFFSET + (m ? Number(m[1]) : 0)
}

function toIssue(baseUrl: string, it: YouTrackIssue): Issue {
  const { column, ...fields } = issueStateFields(latestState(it.comments.map(comment => comment.text)) ?? {})
  return {
    id: `youtrack:${it.idReadable}`,
    externalId: it.idReadable,
    source: 'youtrack',
    number: syntheticNumber(it.idReadable),
    title: it.summary,
    column: column ?? (it.resolved != null ? 'done' : 'todo'),
    htmlUrl: issueHtmlUrl(baseUrl, it.idReadable),
    attachments: it.attachments,
    ...fields,
  }
}

export async function loadYouTrackIssues(ctx: ExtensionContext): Promise<Issue[]> {
  const settings = getSettings(ctx)
  const baseUrl = settings.youtrackBaseUrl.trim()
  const project = settings.youtrackProjectShortName.trim()
  if (!baseUrl || !project)
    return []
  const token = await getYouTrackToken(ctx, youtrackHost(baseUrl))
  if (!token)
    return []
  const workspaceRoot = workspace.workspaceFolders?.[0]?.uri.fsPath
  if (!workspaceRoot)
    return []
  // 只镜像用户主动勾选导入的工单（见 importStore），不再加载即全量同步。
  // import 集为空 ⇒ 返回 []。
  const importedSet = new Set(await readImportedIds(workspaceRoot, project))
  if (importedSet.size === 0)
    return []
  const raw = await listIssues({ baseUrl, token }, project)
  return raw
    .filter(it => importedSet.has(it.idReadable))
    .map(it => toIssue(baseUrl, it))
}