package com.hlab.yanalyst.service;

import com.hlab.yanalyst.domain.opal.*;
import com.hlab.yanalyst.domain.script.ScriptGen;
import com.hlab.yanalyst.domain.script.ScriptGenRepository;
import com.hlab.yanalyst.domain.video.YtVideo;
import com.hlab.yanalyst.domain.video.YtVideoRepository;
import com.hlab.yanalyst.service.external.ExternalApiService;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.List;

@Service
@RequiredArgsConstructor
@Transactional
public class AnalysisWorkflowService {

    private final YtVideoRepository ytVideoRepository;
    private final ScriptGenRepository scriptGenRepository;
    private final OpalDraftRepository opalDraftRepository;
    private final OpalFinalRepository opalFinalRepository;
    private final OpalFinalAssetRepository opalFinalAssetRepository;
    private final ExternalApiService externalApiService;
    private final ObjectMapper objectMapper;

    public ScriptGen generateScript(Long videoId) {
        YtVideo video = ytVideoRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Video not found"));

        String scriptContent = externalApiService.generateScript(video.getVideoUrl());

        ScriptGen scriptGen = scriptGenRepository.findById(videoId).orElse(new ScriptGen());
        if (scriptGen.getVideoId() == null) {
            scriptGen.setVideo(video);
        }
        scriptGen.setResponseText(scriptContent);
        scriptGen.setStatus("SUCCESS");
        // Update video status
        video.setStatus("SCRIPT_READY");
        
        return scriptGenRepository.save(scriptGen);
    }

    public OpalDraft generateDraft(Long videoId, String feedback, String mode) {
        YtVideo video = ytVideoRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Video not found"));
        
        ScriptGen scriptGen = scriptGenRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Script not found"));

        var draftDto = externalApiService.generateOpalDraft(scriptGen.getResponseText(), feedback, mode);

        OpalDraft draft = new OpalDraft();
        draft.setVideo(video);
        draft.setOldScriptSummary(draftDto.getOldScriptSummary());
        draft.setNewScriptSummary(draftDto.getNewScriptSummary());
        // For compatibility, we can concatenate or just leave responseText empty/null, or use New Summary as main response
        draft.setResponseText(draftDto.getNewScriptSummary()); 
        draft.setUserFeedback(feedback);
        
        Integer maxVersion = opalDraftRepository.findByVideo_VideoIdOrderByVersionNoDesc(videoId)
                .stream().findFirst().map(OpalDraft::getVersionNo).orElse(0);
        draft.setVersionNo(maxVersion + 1);
        draft.setStatus("SUCCESS");
        
        video.setStatus("DRAFTING");
        
        return opalDraftRepository.save(draft);
    }

    public OpalFinal acceptDraft(Long videoId, Long draftId) {
        YtVideo video = ytVideoRepository.findById(videoId).orElseThrow();
        OpalDraft draft = opalDraftRepository.findById(draftId).orElseThrow();
        
        if (!draft.getVideo().getVideoId().equals(videoId)) {
            throw new IllegalArgumentException("Draft does not match video");
        }

        // Deactivate existing active final
        opalFinalRepository.findByVideo_VideoIdAndIsActiveTrue(videoId)
                .ifPresent(existing -> {
                    existing.setIsActive(false);
                    opalFinalRepository.save(existing);
                });

        // Mark draft accepted
        draft.setIsAccepted(true);
        draft.setAcceptedAt(LocalDateTime.now());
        opalDraftRepository.save(draft);

        OpalFinal opalFinal = new OpalFinal();
        opalFinal.setVideo(video);
        opalFinal.setDraft(draft);
        opalFinal.setFinalScriptText(draft.getResponseText());
        opalFinal.setIsActive(true);
        
        return opalFinalRepository.save(opalFinal);
    }

    public OpalFinalAsset generateFinalAsset(Long videoId) {
        YtVideo video = ytVideoRepository.findById(videoId).orElseThrow();
        OpalFinal activeFinal = opalFinalRepository.findByVideo_VideoIdAndIsActiveTrue(videoId)
                .orElse(null);

        if (activeFinal == null) {
            OpalDraft latestDraft = opalDraftRepository.findByVideo_VideoIdOrderByVersionNoDesc(videoId)
                    .stream().findFirst()
                    .orElseThrow(() -> new IllegalArgumentException("No active final script and no drafts found. Please generate a draft first."));

            activeFinal = new OpalFinal();
            activeFinal.setVideo(video);
            activeFinal.setDraft(latestDraft);
            activeFinal.setIsActive(true);
            activeFinal.setFinalScriptText("");
            activeFinal = opalFinalRepository.save(activeFinal);
        }

        // 1. Fetch updated final script from external source (GDoc)
        String updatedFinalScript = externalApiService.fetchFinalScript();
        
        // 2. Update and save active final script
        activeFinal.setFinalScriptText(updatedFinalScript);
        opalFinalRepository.save(activeFinal);

        // 3. Generate asset metadata
        var assetMap = externalApiService.generateFinalAsset(activeFinal.getFinalScriptText());

        OpalFinalAsset asset = new OpalFinalAsset();
        asset.setOpalFinal(activeFinal);
        try {
            asset.setAssetJson(objectMapper.writeValueAsString(assetMap));
            asset.setTitle((String) assetMap.get("title"));
            asset.setSummary((String) assetMap.get("summary"));
            asset.setTimeline(objectMapper.writeValueAsString(assetMap.get("timeline")));
            asset.setVideoPrompt((String) assetMap.get("video_prompt"));
            asset.setImageUrls(objectMapper.writeValueAsString(assetMap.get("image_urls")));
        } catch (Exception e) {
            throw new RuntimeException("JSON processing error", e);
        }

        video.setStatus("FINALIZED");
        return opalFinalAssetRepository.save(asset);
    }
    public boolean toggleComplete(Long videoId) {
        YtVideo video = ytVideoRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Video not found"));
        
        boolean newState = video.getIsCompleted() == null ? true : !video.getIsCompleted();
        video.setIsCompleted(newState);
        ytVideoRepository.save(video);
        return newState;
    }

    public void updateFinalAsset(Long videoId, String newText) {
        OpalFinal opalFinal = opalFinalRepository.findByVideo_VideoIdAndIsActiveTrue(videoId)
                .orElseThrow(() -> new IllegalArgumentException("No active final asset found for videoId: " + videoId));
        opalFinal.setFinalScriptText(newText);
        opalFinalRepository.save(opalFinal);
    }
    
    public void generateOpening(Long videoId, String docId) {
        YtVideo video = ytVideoRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Video not found"));
        
        String openingScript = externalApiService.fetchOpeningScript(docId);
        video.setOpeningScript(openingScript);
        ytVideoRepository.save(video);
    }

    public void resetOpening(Long videoId) {
        YtVideo video = ytVideoRepository.findById(videoId)
                .orElseThrow(() -> new IllegalArgumentException("Video not found"));
        video.setOpeningScript(null);
        ytVideoRepository.save(video);
    }
}