const express = require('express');
const router = express.Router();
const { callAI } = require('../utils/ai');
const PROMPTS = require('../utils/prompts');
const { authMiddleware } = require('../middleware/auth');

// Generate hospital course
router.post('/generate-hospital-course', authMiddleware, async (req, res) => {
  try {
    const {
      notes,          // Array of { date, type, content }
      edNote,         // { date, content, labs }
      hAndP,          // { date, content }
      labs,           // Array of { date, values }
      patientAge, patientGender, pmh,
      setting,        // 'floor' | 'picu' | 'nicu' | 'psych'
      los,            // length of stay
      model,
      formatPreference, // 'auto' | 'prose' | 'dayByDay' | 'organSystem'
      additionalInstructions,
      physicianMemories
    } = req.body;

    if (!notes || notes.length === 0) {
      return res.status(400).json({ error: 'No notes provided' });
    }

    // Determine format
    let prompt;
    let format = formatPreference || 'auto';

    if (format === 'auto') {
      if (setting === 'picu' || setting === 'nicu') {
        format = 'organSystem';
      } else if (setting === 'psych') {
        format = 'psych';
      } else if (los && parseInt(los) > 3) {
        format = 'dayByDay';
      } else {
        format = 'prose';
      }
    }

    switch (format) {
      case 'organSystem': prompt = PROMPTS.hospitalCourseICU; break;
      case 'dayByDay': prompt = PROMPTS.hospitalCourseLong; break;
      case 'psych': prompt = PROMPTS.hospitalCoursePsych; break;
      default: prompt = PROMPTS.hospitalCourseShort;
    }

    // Build the complete clinical data
    let clinicalData = `Patient: ${patientAge || 'Unknown'}, ${patientGender || 'Unknown'}`;
    if (pmh) clinicalData += `\nPMH: ${pmh}`;
    if (setting) clinicalData += `\nSetting: ${setting}`;
    if (los) clinicalData += `\nLength of Stay: ${los} days`;
    clinicalData += `\nFormat: ${format}`;

    if (edNote) {
      clinicalData += `\n\n=== ED NOTE (${edNote.date || 'date unknown'}) ===\n${edNote.content}`;
      if (edNote.labs) clinicalData += `\nED Labs: ${edNote.labs}`;
    }

    if (hAndP) {
      clinicalData += `\n\n=== H&P (${hAndP.date || 'date unknown'}) ===\n${hAndP.content}`;
    }

    // Sort notes by date
    const sortedNotes = [...notes].sort((a, b) => new Date(a.date) - new Date(b.date));
    sortedNotes.forEach((note, i) => {
      clinicalData += `\n\n=== ${(note.type || 'Progress Note').toUpperCase()} - ${note.date || `Note ${i + 1}`} ===\n${note.content}`;
    });

    if (labs && labs.length > 0) {
      clinicalData += '\n\n=== LABS ===';
      labs.forEach(lab => {
        clinicalData += `\n${lab.date}: ${lab.values}`;
      });
    }

    if (additionalInstructions) {
      prompt += `\n\nADDITIONAL INSTRUCTIONS FROM PHYSICIAN:\n${additionalInstructions}`;
    }

    if (physicianMemories) clinicalData += '\n\n[PHYSICIAN PREFERENCES & LEARNED PATTERNS — Apply these preferences to your output. These reflect how this physician writes notes, their preferred style, terminology, and corrections from past outputs. Adapt your response accordingly, but user instructions in the current prompt take priority if they conflict.]\n' + physicianMemories + '\n[END PREFERENCES]';

    const result = await callAI([
      { role: 'system', content: prompt },
      { role: 'user', content: clinicalData }
    ], { model, maxTokens: 6000 });

    res.json({
      success: true,
      hospitalCourse: result.content,
      format: format,
      model: result.model
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Ask for clarification/missing info
router.post('/hospital-course-clarify', authMiddleware, async (req, res) => {
  try {
    const { currentDraft, notes } = req.body;

    const result = await callAI([
      { role: 'system', content: PROMPTS.askClarification },
      { role: 'user', content: `Current draft:\n${currentDraft}\n\nSource notes:\n${JSON.stringify(notes)}` }
    ], { model: req.body.model });

    res.json({ success: true, questions: result.content, model: result.model });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Add discharge day info
router.post('/hospital-course-update', authMiddleware, async (req, res) => {
  try {
    const { currentCourse, updates, model, instructions } = req.body;
    if (!currentCourse) return res.status(400).json({ error: 'No current course' });

    let userMsg = `CURRENT HOSPITAL COURSE:\n${currentCourse}\n\n`;
    if (updates) userMsg += `NEW UPDATES TO ADD:\n${updates}\n\n`;
    if (instructions) userMsg += `INSTRUCTIONS:\n${instructions}`;

    const result = await callAI([
      { role: 'system', content: `You are updating a hospital course document with new information.
Add the new information in the appropriate place. Maintain the same format and style.
If adding discharge day information, add it at the end.
${PROMPTS.refine.split('\n').slice(0, -1).join('\n')}` },
      { role: 'user', content: userMsg }
    ], { model, maxTokens: 6000 });

    res.json({ success: true, hospitalCourse: result.content, model: result.model });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;