/**
 * 机器本地的工单状态(会话 id、worktree 路径、profile 路径等)。
 *
 * 这些字段描述"这台机器上"的会话与文件系统,跨机毫无语义(别人机器的
 * 绝对路径/会话 id 在本机不可用),写进 Gitea 共享评论只会互相污染——
 * 所以落在 workspaceState,按 `source:number` 键控。共享评论里的旧数据
 * 仍按读兜底(本地无记录时透出),写侧从此只产生本地记录。
 */

import type { ExtensionContext } from 'vscode'
import type { Issue } from '../gitea/types'
import * as fs from 'node:fs'
import { resolveWorktreePath } from '../git/worktree'

export const LOCAL_STATE_FIELDS = [
  'sessionId',
  'implementSessionId',
  'reviewSessionId',
  'testSessionId',
  'prototypeSessionId',
  'profilePath',
  'brainstormProfilePath',
  'testProfilePath',
  'prototypeProfilePath',
  'worktreePath',
  'prDiffFile',
] as const

const KEY = 'superpowers.localIssueState'

type Store = Record<string, Record<string, string>>

function refKey(source: string | undefined, issueNumber: number): string {
  return `${source ?? 'gitea'}:${issueNumber}`
}

export function getLocalIssueState(
  ctx: ExtensionContext,
  source: string | undefined,
  issueNumber: number,
): Record<string, string> {
  const store = ctx.workspaceState.get<Store>(KEY) ?? {}
  return store[refKey(source, issueNumber)] ?? {}
}

/**
 * 空字符串是墓碑:字段已在本机清除,读侧不得回落到共享评论里的旧值
 * (与 state JSON "空串=unset" 的既有约定一致)。null/undefined 视作清除。
 */
export async function mergeLocalIssueState(
  ctx: ExtensionContext,
  source: string | undefined,
  issueNumber: number,
  patch: Record<string, unknown>,
): Promise<void> {
  const store = { ...(ctx.workspaceState.get<Store>(KEY) ?? {}) }
  const key = refKey(source, issueNumber)
  const next = { ...(store[key] ?? {}) }
  for (const [k, v] of Object.entries(patch)) {
    if (typeof v === 'string')
      next[k] = v
    else if (v === null || v === undefined)
      next[k] = ''
  }
  store[key] = next
  await ctx.workspaceState.update(KEY, store)
}

/** 把一次状态写入分成本地字段与共享字段两半。 */
export function splitLocalStateFields(extra: Record<string, unknown>): {
  local: Record<string, unknown>
  shared: Record<string, unknown>
} {
  const localSet = new Set<string>(LOCAL_STATE_FIELDS)
  const local: Record<string, unknown> = {}
  const shared: Record<string, unknown> = {}
  for (const [k, v] of Object.entries(extra)) {
    if (localSet.has(k))
      local[k] = v
    else
      shared[k] = v
  }
  return { local, shared }
}

/**
 * 把本地记录叠加到加载出的工单列表上:本地有键即生效('' 墓碑 → 置空)。
 * 覆盖 worktreePath 时同步重算 worktreeExists,口径与 buildIssue 一致。
 */
export function overlayLocalIssueState(
  ctx: ExtensionContext,
  issues: Issue[],
  workspaceRoot?: string,
): Issue[] {
  const store = ctx.workspaceState.get<Store>(KEY) ?? {}
  return issues.map((issue) => {
    const local = store[refKey(issue.source, issue.number)]
    if (!local)
      return issue
    const out = { ...issue } as Issue & Record<string, unknown>
    for (const field of LOCAL_STATE_FIELDS) {
      const v = local[field]
      if (v === undefined)
        continue
      if (v === '')
        delete out[field]
      else
        out[field] = v
      if (field === 'worktreePath') {
        delete out.worktreeExists
        if (v !== '' && workspaceRoot) {
          try {
            out.worktreeExists = fs.existsSync(resolveWorktreePath(v, workspaceRoot))
          }
          catch {
            out.worktreeExists = false
          }
        }
      }
    }
    return out
  })
}