import {
  HEALTH_ACTIONS,
  HEALTH_CHANNEL_STEPS,
  createIdleHealthChannelState,
  reduceHealthChannel,
} from './health-channel-state.mjs';
import { isHealthEnterText, matchHealthIdleRules } from './health-intent-rules.mjs';
import { matchHealthMenuAlias } from './health-channel-aliases.mjs';
import { inferBloodPressureContext, validateBloodPressurePair } from './health-observation-validate.mjs';
import { isMemindHealthEnabled } from './health-feature.mjs';
import {
  buildPendingValuesFromParsed,
  formatCommittedReply,
  formatGenericConfirmCard,
  metricValuePrompt,
  parseMetricInput,
} from './health-metric-input.mjs';

export const HEALTH_WECHAT_EVENT_KEY = 'MEMIND_HEALTH';
export const HEALTH_CHANNEL_TTL_MS = 30 * 60 * 1000;

export const HEALTH_MENU_TEXT = [
  '已进入【健康助手】专用通道',
  '本通道只处理健康相关内容，数据确认后才会写入你的健康档案。',
  '',
  '请回复数字：',
  '1  健康录入（血压/心率/体重/血氧/体温/睡眠/症状）',
  '2  上传报告（请发送照片，P0 先归档说明，数值请手输确认）',
  '3  健康评估（基于档案的文字摘要）',
  '4  查看健康档案',
  '0  退出健康通道',
].join('\n');

export { isHealthEnterText } from './health-intent-rules.mjs';

export function isHealthMenuEvent(inbound = {}) {
  const event = String(inbound.event ?? inbound.Event ?? '').toLowerCase();
  const eventKey = String(inbound.eventKey ?? inbound.EventKey ?? '').trim();
  return event === 'click' && eventKey === HEALTH_WECHAT_EVENT_KEY;
}

export function shouldFallThroughWechatHealthMenuEvent(inbound, env = process.env) {
  return isMemindHealthEnabled(env) && isHealthMenuEvent(inbound);
}

export function formatConfirmCard({ systolic, diastolic, pulse = null, context = 'other' }) {
  const lines = [
    `已识别 → 收缩压 ${systolic}，舒张压 ${diastolic}${pulse ? `，脉搏 ${pulse}` : ''}`,
    `情境：${context === 'morning' ? '晨间' : context === 'evening' ? '晚间' : '其他'}`,
    '回复「1」确认保存 | 「2」修改 | 「0」放弃',
  ];
  return lines.join('\n');
}

export function applyHealthChannelTurn({
  channel = 'wechat',
  session = null,
  text = '',
  msgType = 'text',
  eventKey = '',
  forceEnter = false,
  now = Date.now(),
  observedAt = null,
} = {}) {
  const trimmed = String(text ?? '').trim();
  const enter = forceEnter || eventKey === HEALTH_WECHAT_EVENT_KEY || isHealthEnterText(trimmed);
  let wrapper = session;

  if (!wrapper && !enter && msgType !== 'image') {
    return { handled: false };
  }

  if (!wrapper && enter) {
    return {
      handled: true,
      session: {
        channelState: createIdleHealthChannelState({ channel }),
        pendingValues: null,
      },
      reply: HEALTH_MENU_TEXT,
      commit: null,
    };
  }

  if (!wrapper) {
    return { handled: false };
  }

  if (trimmed === '0' || trimmed === '退出') {
    return {
      handled: true,
      session: null,
      reply: '已退出健康通道。之后的消息会回到普通聊天。',
      commit: null,
    };
  }

  let channelState = wrapper.channelState ?? createIdleHealthChannelState({ channel: 'wechat' });
  let pendingValues = wrapper.pendingValues ?? null;

  if (msgType === 'image') {
    if (channelState.action === HEALTH_ACTIONS.DOCUMENT) {
      return {
        handled: true,
        session: {
          channelState: createIdleHealthChannelState({ channel }),
          pendingValues: null,
        },
        reply: '已收到报告照片。P0 会归档原图到健康区；指标抽取与 OCR 将在后续版本开放。回复「1」继续录入，或「0」退出。',
        commit: { type: 'document', confirmed: true, source: channel === 'h5' ? 'manual' : 'wechat' },
      };
    }
    if (channelState.step === HEALTH_CHANNEL_STEPS.AWAIT_VALUE) {
      return {
        handled: true,
        session: { channelState, pendingValues },
        reply: '已收到照片。P0 请回复数值（如 137/82）并确认后再保存，避免识别漂移。',
        commit: null,
      };
    }
    return {
      handled: true,
      session: { channelState, pendingValues },
      reply: '请先回复「1」选择健康录入，再发送数值。照片不会直接入库。',
      commit: null,
    };
  }

  if (channelState.step === HEALTH_CHANNEL_STEPS.IDLE) {
    const menuAlias = matchHealthMenuAlias(trimmed);
    if (menuAlias === 'menu') {
      return {
        handled: true,
        session: { channelState, pendingValues },
        reply: HEALTH_MENU_TEXT,
        commit: null,
      };
    }
    if (menuAlias && menuAlias !== 'menu') {
      return applyHealthChannelTurn({
        channel,
        session,
        text: menuAlias,
        msgType,
        eventKey,
        now,
        observedAt,
      });
    }
    if (trimmed === '1') {
      const reduced = reduceHealthChannel(channelState, {
        type: 'select_action',
        action: HEALTH_ACTIONS.RECORD,
      });
      return {
        handled: true,
        session: { channelState: reduced.state, pendingValues: null },
        reply: '请选择要录入的指标：\n1 血压  2 心率  3 体重  4 血氧\n5 体温  6 睡眠  7 症状  8 用药',
        commit: null,
      };
    }
    if (trimmed === '2') {
      const reduced = reduceHealthChannel(channelState, {
        type: 'select_action',
        action: HEALTH_ACTIONS.DOCUMENT,
      });
      return {
        handled: true,
        session: { channelState: reduced.state, pendingValues: null },
        reply: '请发送报告照片（体检单/化验单/影像报告/PDF 截图）。收到后会归档到健康区；P0 暂不自动抽取指标，关键数值请手输确认。',
        commit: null,
      };
    }
    if (trimmed === '3' && channel !== 'h5') {
      return {
        handled: true,
        session: { channelState, pendingValues },
        reply: '健康评估会在个人基线成熟后开启。请先按规程连续记录，下次进入时优先展示未读提醒。',
        commit: null,
      };
    }
    if (trimmed === '4') {
      return {
        handled: true,
        session: { channelState, pendingValues },
        reply: '请到网页「健康档案区」查看加密档案。本人登录免密，外部访问必须口令。',
        commit: null,
      };
    }
    const rule = matchHealthIdleRules(trimmed);
    if (rule.matched && rule.intent === 'blood_pressure' && rule.extracted?.systolic && rule.extracted?.diastolic) {
      const pair = validateBloodPressurePair(rule.extracted.systolic, rule.extracted.diastolic);
      if (!pair.ok) {
        return {
          handled: true,
          session: { channelState, pendingValues },
          reply: '数值无法确认（超量程或收缩压不大于舒张压）。请重新发送，如 137/82。',
          commit: null,
        };
      }
      const context = inferBloodPressureContext(observedAt ?? now);
      const confirmState = reduceHealthChannel(
        {
          ...createIdleHealthChannelState({ channel }),
          step: HEALTH_CHANNEL_STEPS.AWAIT_VALUE,
          metricSet: 'blood_pressure',
          context,
        },
        { type: 'submit_value', draftId: `bp-${now}` },
      );
      return {
        handled: true,
        session: {
          channelState: confirmState.state,
          pendingValues: {
            metricSet: 'blood_pressure',
            systolic: pair.systolic,
            diastolic: pair.diastolic,
            context,
            observedAt: observedAt ?? now,
          },
        },
        reply: formatConfirmCard({
          systolic: pair.systolic,
          diastolic: pair.diastolic,
          context,
        }),
        commit: null,
      };
    }
    // H5 健康通道：idle 自由文本交给 health-assistant Agent（已注入档案摘要）
    if (channel === 'h5' && trimmed) {
      return { handled: false };
    }
    return {
      handled: true,
      session: { channelState, pendingValues },
      reply: HEALTH_MENU_TEXT,
      commit: null,
    };
  }

  if (channelState.step === HEALTH_CHANNEL_STEPS.AWAIT_METRIC_TYPE) {
    if (trimmed === '8') {
      return {
        handled: true,
        session: { channelState: createIdleHealthChannelState({ channel }), pendingValues: null },
        reply: '用药记录将在 P3 与日程助手整合。P0 请先用手输录入其它指标，或到 MindSpace 健康区查看档案。',
        commit: null,
      };
    }
    const reduced = reduceHealthChannel(channelState, { type: 'choose', choice: Number(trimmed) });
    if (reduced.actions[0]?.type === 'prompt_context') {
      return {
        handled: true,
        session: { channelState: reduced.state, pendingValues: null },
        reply: '请选择测量情境：1 晨间  2 晚间  3 其他（可直接发送 137/82）',
        commit: null,
      };
    }
    if (reduced.actions[0]?.type === 'prompt_value') {
      const metricSet = reduced.state.metricSet;
      return {
        handled: true,
        session: { channelState: reduced.state, pendingValues: null },
        reply: metricValuePrompt(metricSet),
        commit: null,
      };
    }
    return {
      handled: true,
      session: { channelState, pendingValues },
      reply: '请回复 1-8 选择指标。',
      commit: null,
    };
  }

  if (channelState.step === HEALTH_CHANNEL_STEPS.AWAIT_CONTEXT) {
    const context = trimmed === '1' ? 'morning' : trimmed === '2' ? 'evening' : 'other';
    const reduced = reduceHealthChannel(channelState, { type: 'pick_context', context });
    return {
      handled: true,
      session: { channelState: reduced.state, pendingValues: { context } },
      reply: '请发送血压数值，如 137/82。',
      commit: null,
    };
  }

  if (channelState.step === HEALTH_CHANNEL_STEPS.AWAIT_VALUE) {
    const metricSet = channelState.metricSet ?? 'blood_pressure';

    if (metricSet === 'blood_pressure') {
      const rule = matchHealthIdleRules(trimmed);
      if (rule.intent === 'blood_pressure' && rule.extracted?.systolic) {
        const pair = validateBloodPressurePair(rule.extracted.systolic, rule.extracted.diastolic);
        if (!pair.ok) {
          return {
            handled: true,
            session: { channelState, pendingValues },
            reply: '数值无法确认，请按 137/82 格式重发。',
            commit: null,
          };
        }
        const context = pendingValues?.context
          || channelState.context
          || inferBloodPressureContext(observedAt ?? now);
        const reduced = reduceHealthChannel(channelState, {
          type: 'submit_value',
          draftId: `bp-${now}`,
        });
        const pending = buildPendingValuesFromParsed(
          { metricSet: 'blood_pressure', systolic: pair.systolic, diastolic: pair.diastolic, label: `${pair.systolic}/${pair.diastolic}` },
          { context, observedAt: observedAt ?? now },
        );
        return {
          handled: true,
          session: {
            channelState: reduced.state,
            pendingValues: pending,
          },
          reply: formatConfirmCard({
            systolic: pair.systolic,
            diastolic: pair.diastolic,
            context,
          }),
          commit: null,
        };
      }
    } else {
      const parsed = parseMetricInput(metricSet, trimmed);
      if (parsed.ok) {
        const reduced = reduceHealthChannel(channelState, {
          type: 'submit_value',
          draftId: `${metricSet}-${now}`,
        });
        const pending = buildPendingValuesFromParsed(parsed, { observedAt: observedAt ?? now });
        return {
          handled: true,
          session: {
            channelState: reduced.state,
            pendingValues: pending,
          },
          reply: formatGenericConfirmCard({
            metricSet,
            label: parsed.label,
            context: pending.context,
          }),
          commit: null,
        };
      }
      if (parsed.error === 'out_of_range' || parsed.error === 'not_numeric' || parsed.error === 'unknown_symptom') {
        return {
          handled: true,
          session: { channelState, pendingValues },
          reply: `无法确认该数值。${metricValuePrompt(metricSet)}`,
          commit: null,
        };
      }
    }

    const unexpected = reduceHealthChannel(channelState, { type: 'unexpected', text: trimmed });
    return {
      handled: true,
      session: { channelState: unexpected.state, pendingValues },
      reply: unexpected.actions[0]?.prompt || metricValuePrompt(metricSet),
      commit: null,
    };
  }

  if (channelState.step === HEALTH_CHANNEL_STEPS.CONFIRM) {
    if (trimmed === '1') {
      const reduced = reduceHealthChannel(channelState, { type: 'commit' });
      return {
        handled: true,
        session: {
          channelState: createIdleHealthChannelState({ channel }),
          pendingValues: null,
        },
        reply: pendingValues
          ? formatCommittedReply(pendingValues)
          : '已记录。回复「0」退出。',
        commit: pendingValues
          ? { confirmed: true, values: pendingValues, source: channel === 'h5' ? 'manual' : 'wechat' }
          : null,
      };
    }
    if (trimmed === '2') {
      const reduced = reduceHealthChannel(channelState, { type: 'revise' });
      return {
        handled: true,
        session: { channelState: reduced.state, pendingValues },
        reply: '请重新发送数值，如 137/82。',
        commit: null,
      };
    }
    const discarded = reduceHealthChannel(channelState, { type: 'discard' });
    return {
      handled: true,
      session: { channelState: discarded.state, pendingValues: null },
      reply: '已放弃本次录入。' + HEALTH_MENU_TEXT,
      commit: null,
    };
  }

  void now;
  return {
    handled: true,
    session: { channelState, pendingValues },
    reply: HEALTH_MENU_TEXT,
    commit: null,
  };
}

export function applyHealthWechatTurn(options = {}) {
  return applyHealthChannelTurn({ ...options, channel: 'wechat' });
}