"""定制简历存取 + 数据转换模块

提供定制简历的保存（数据库持久化）、查询、回滚（Redis临时备份）、从 ResumeDetail 构建能力。
各 Service 统一复用，不直接操作数据库表和 Redis key。
"""

import random
import string

from sqlalchemy import select, update

from app.core.database import get_db
from app.core.redis import RedisManager
from app.models.user_job_customize_resume import UserJobCustomizeResume
from app.schemas.customize_resume import (
    CustomizeResume, ResumeProfile, Education, Work, Internship, Project, Competition, Paragraph,
)
from app.services.resume_loader import ResumeDetail, load_default_resume_detail
from app.tool.snowflake import next_id

# Redis 回滚常量
ROLLBACK_PREFIX = "customize:resume:rollback:"
ROLLBACK_EXPIRE = 30 * 60  # 30分钟

_CHARS = string.ascii_letters + string.digits


def _rand_id() -> str:
    """生成随机8位字符串标识"""
    return "".join(random.choices(_CHARS, k=8))


def _build_paragraphs(description: list[dict] | None) -> list[Paragraph]:
    """将数据库 description [{id, text}] 转为 Paragraph 列表"""
    if not description:
        return []
    return [Paragraph(id=_rand_id(), text=item.get("text", "")) for item in description if isinstance(item, dict)]


def build_from_detail(detail: ResumeDetail) -> CustomizeResume:
    """从 ResumeDetail 组装 CustomizeResume"""
    resume = detail.resume
    profile = ResumeProfile(
        avatarUrl=resume.avatar_url or "", name=resume.name or "", email=resume.email or "",
        mobileNumber=resume.mobile_number or "", city=resume.city or "",
        wechatNumber=resume.wechat_number or "", portfolioUrl=resume.portfolio_url or "",
        skills=resume.skills or [], certificates=resume.certificates or [],
        summary=resume.summary or "",
    )
    return CustomizeResume(
        resume=profile,
        education=[Education(id=_rand_id(), school=r.school or "", major=r.major or "",
                             degree=r.degree or "", studyType=r.study_type or "",
                             startDate=r.start_date or "", endDate=r.end_date or "",
                             description=_build_paragraphs(r.description)) for r in detail.education],
        work=[Work(id=_rand_id(), companyName=r.company_name or "", position=r.position or "",
                   startDate=r.start_date or "", endDate=r.end_date or "",
                   description=_build_paragraphs(r.description)) for r in detail.work],
        internship=[Internship(id=_rand_id(), companyName=r.company_name or "", position=r.position or "",
                               startDate=r.start_date or "", endDate=r.end_date or "",
                               description=_build_paragraphs(r.description)) for r in detail.internship],
        project=[Project(id=_rand_id(), companyName=r.company_name or "", projectName=r.project_name or "",
                         role=r.role or "", startDate=r.start_date or "", endDate=r.end_date or "",
                         description=_build_paragraphs(r.description)) for r in detail.project],
        competition=[Competition(id=_rand_id(), competitionName=r.competition_name or "", award=r.award or "",
                                 awardDate=r.award_date or "",
                                 description=_build_paragraphs(r.description)) for r in detail.competition],
    )


def _rollback_key(user_id: int, job_id: int) -> str:
    return f"{ROLLBACK_PREFIX}{user_id}:{job_id}"


async def save(user_id: int, job_id: int, cr: CustomizeResume) -> None:
    """保存定制简历：备份旧版本到 Redis 用于回滚 + 写数据库"""
    content = cr.model_dump(by_alias=True)

    async for session in get_db():
        # 查已有记录，备份旧版本到 Redis 用于回滚
        result = await session.execute(select(UserJobCustomizeResume).where(UserJobCustomizeResume.user_id == user_id, UserJobCustomizeResume.job_id == job_id))
        record = result.scalar_one_or_none()
        if record:
            old_cr = CustomizeResume.model_validate(record.content)
            await RedisManager.client.set(_rollback_key(user_id, job_id), old_cr.model_dump_json(by_alias=True), ex=ROLLBACK_EXPIRE)
            await session.execute(update(UserJobCustomizeResume).where(
                UserJobCustomizeResume.id == record.id).values(content=content))
        else:
            session.add(UserJobCustomizeResume(id=next_id(), user_id=user_id, job_id=job_id, content=content))


async def get(user_id: int, job_id: int) -> dict | None:
    """查询定制简历，查不到则加载默认简历构建返回"""
    data = None
    async for session in get_db():
        result = await session.execute(select(UserJobCustomizeResume).where(
            UserJobCustomizeResume.user_id == user_id, UserJobCustomizeResume.job_id == job_id))
        record = result.scalar_one_or_none()
        if record:
            data = CustomizeResume.model_validate(record.content).model_dump(by_alias=True)
        else:
            # 没有定制简历，加载默认简历构建
            detail = await load_default_resume_detail(session, user_id)
            data = build_from_detail(detail).model_dump(by_alias=True)
    return data


async def rollback(user_id: int, job_id: int) -> None:
    """回滚定制简历到上一版本：从 Redis 取回滚数据写入数据库"""
    rollback_k = _rollback_key(user_id, job_id)
    data = await RedisManager.client.get(rollback_k)
    if not data:
        raise ValueError("没有可回滚的版本")
    content = CustomizeResume.model_validate_json(data).model_dump(by_alias=True)

    async for session in get_db():
        result = await session.execute(select(UserJobCustomizeResume).where(
            UserJobCustomizeResume.user_id == user_id, UserJobCustomizeResume.job_id == job_id))
        record = result.scalar_one_or_none()
        if record:
            await session.execute(update(UserJobCustomizeResume).where(
                UserJobCustomizeResume.id == record.id).values(content=content))
        else:
            session.add(UserJobCustomizeResume(id=next_id(), user_id=user_id, job_id=job_id, content=content))
        await RedisManager.client.delete(rollback_k)