package chatgpt

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"strings"
	"sync"

	"github.com/gin-gonic/gin"

	"aurora/conversion/response/chatgpt"
	"aurora/httpclient"
	"aurora/internal/accounts"
	"aurora/internal/sseparser"
	"aurora/typings"
	chatgpt_types "aurora/typings/chatgpt"
	official_types "aurora/typings/official"

	"github.com/bogdanfinn/websocket"
)

type conversationPatchState struct {
	response chatgpt_types.ChatGPTResponse
	channel  string
}

type conversationStreamEvent struct {
	response       chatgpt_types.ChatGPTResponse
	chunk          *official_types.ChatCompletionChunk
	text           string
	role           string
	conversationID string
	messageID      string
	channel        string
	finishReason   string
	isStop         bool
}

func parseConversationEvent(line string, state *sseparser.PatchState, model string) (conversationStreamEvent, bool) {
	var raw map[string]interface{}
	if err := json.Unmarshal([]byte(line), &raw); err != nil {
		return conversationStreamEvent{}, false
	}

	if chunk, ok := sseparser.ChunkFromRaw(raw, model); ok {
		event := conversationStreamEvent{
			chunk:          &chunk,
			text:           sseparser.ChunkContent(chunk),
			role:           sseparser.ChunkRole(chunk),
			conversationID: chunk.ConversationID,
			channel:        sseparser.ChannelFromValue(raw),
			finishReason:   sseparser.ChunkFinishReason(chunk),
		}
		event.isStop = event.finishReason != ""
		return event, true
	}

	var direct chatgpt_types.ChatGPTResponse
	if err := json.Unmarshal([]byte(line), &direct); err == nil && sseparser.IsUsableConversationResponse(direct) {
		channel := sseparser.ChannelFromValue(raw)
		state.Channel = firstNonEmpty(channel, state.Channel)
		return conversationStreamEvent{response: direct, messageID: direct.Message.ID, channel: state.Channel}, true
	}

	if response, ok := sseparser.ResponseFromValue(raw["v"]); ok {
		state.Response = response
		if channel := sseparser.ChannelFromValue(raw["v"]); channel != "" {
			state.Channel = channel
		}
		return conversationStreamEvent{response: state.Response, messageID: state.Response.Message.ID, channel: state.Channel}, true
	}
	if text, ok := raw["v"].(string); ok && raw["p"] == nil && raw["o"] == nil {
		sseparser.EnsurePatchDefaults(state)
		current, _ := state.Response.Message.Content.Parts[0].(string)
		state.Response.Message.Content.Parts[0] = current + text
		return conversationStreamEvent{response: state.Response, messageID: state.Response.Message.ID, channel: state.Channel}, true
	}

	if patchPath, ok := raw["p"].(string); ok {
		patchOperation, _ := raw["o"].(string)
		if patchPath == "" && patchOperation == "patch" {
			if batch, ok := raw["v"].([]interface{}); ok {
				applied := false
				for _, item := range batch {
					op, ok := item.(map[string]interface{})
					if !ok {
						continue
					}
					subPath, _ := op["p"].(string)
					subOp, _ := op["o"].(string)
					if sseparser.ApplyPatch(state, subPath, subOp, op["v"]) {
						applied = true
					}
				}
				if applied {
					return conversationStreamEvent{response: state.Response, messageID: state.Response.Message.ID, channel: state.Channel}, true
				}
			}
		}
		if sseparser.ApplyPatch(state, patchPath, patchOperation, raw["v"]) {
			return conversationStreamEvent{response: state.Response, messageID: state.Response.Message.ID, channel: state.Channel}, true
		}
	}

	return conversationStreamEvent{}, false
}

// Handler 处理对话响应（简化版）。
func Handler(c *gin.Context, response *http.Response, client httpclient.AuroraHttpClient, account *accounts.Account, uuid string, translated_request chatgpt_types.ChatGPTRequest, stream bool, model string) (string, *ContinueInfo) {
	result := HandlerDetailed(c, response, client, account, uuid, translated_request, stream, model)
	return result.Text, result.Continue
}

// HandlerDetailed 处理对话响应（详细版）。
func HandlerDetailed(c *gin.Context, response *http.Response, client httpclient.AuroraHttpClient, account *accounts.Account, uuid string, translated_request chatgpt_types.ChatGPTRequest, stream bool, model string) HandlerResult {
	return HandlerDetailedWithWebsocket(c, response, client, account, uuid, translated_request, stream, model, nil)
}

// HandlerDetailedWithWebsocket 处理对话响应（带 WebSocket）。
func HandlerDetailedWithWebsocket(c *gin.Context, response *http.Response, client httpclient.AuroraHttpClient, account *accounts.Account, uuid string, translated_request chatgpt_types.ChatGPTRequest, stream bool, model string, wsConn *websocket.Conn) HandlerResult {
	return HandlerDetailedWithOptions(c, response, client, account, uuid, translated_request, stream, model, HandlerDetailedOptions{Websocket: wsConn})
}

// HandlerDetailedOptions 是 HandlerDetailedWithOptions 的可选参数。
type HandlerDetailedOptions struct {
	Websocket        *websocket.Conn
	ClientState      *ChatClientState
	ArtifactDelivery string
	ProxyURL         string
	Tools            []official_types.Tool
}

// HandlerDetailedWithOptions 处理对话响应流（最完整版）。
func HandlerDetailedWithOptions(c *gin.Context, response *http.Response, client httpclient.AuroraHttpClient, account *accounts.Account, uuid string, translated_request chatgpt_types.ChatGPTRequest, stream bool, model string, options HandlerDetailedOptions) HandlerResult {
	if model == "" {
		model = translated_request.Model
	}
	wsConn := options.Websocket
	if options.ClientState != nil {
		options.ClientState.ApplyToRequest(&translated_request)
	}
	max_tokens := false

	reader := bufio.NewReader(response.Body)
	if wsConn != nil {
		// The orchestration layer may establish this connection for a
		// non-streaming extended/max request before posting the conversation.
		defer wsConn.Close()
	} else if stream && client != nil && account != nil {
		// Preserve the fallback for streaming callers that did not establish a
		// WebSocket before entering the response handler.
		if conn, err := DialChatWebsocketWithStateAndProxy(client, account, options.ClientState, options.ProxyURL); err == nil {
			wsConn = conn
			defer wsConn.Close()
		}
	}

	if stream {
		c.Header("Content-Type", "text/event-stream")
		c.Header("Cache-Control", "no-cache")
		c.Header("Connection", "keep-alive")
		c.Header("X-Accel-Buffering", "no")
	} else {
		c.Header("Content-Type", "application/json")
	}
	var finish_reason string
	var previous_text typings.StringStruct
	var original_response chatgpt_types.ChatGPTResponse
	var isRole = true
	var waitSource = false
	var isEnd = false
	var imgSource []string
	var convId string
	var sentinel []map[string]interface{}
	var thinkingText string
	var activeChannel string
	var assistantMessageID string
	artifactState := newArtifactAccumulator()
	artifactConfig := ArtifactStreamConfig{Delivery: options.ArtifactDelivery}
	var patchState sseparser.PatchState
	var handoffTopicID string
	var currentEvent string
	var readingWebsocket bool
	var websocketStream io.ReadCloser
	emitSentinels := func(items []map[string]interface{}) {
		if len(items) == 0 {
			return
		}
		sentinel = append(sentinel, items...)
		if !stream {
			return
		}
		for _, item := range items {
			chunk := official_types.NewChatCompletionChunk("", model)
			if convId != "" {
				chunk.ConversationID = convId
			}
			chunk.Sentinel = item
			c.Writer.WriteString("data: " + chunk.String() + "\n\n")
			c.Writer.Flush()
		}
	}
	observeArtifacts := func(line string) {
		var raw map[string]interface{}
		if err := json.Unmarshal([]byte(line), &raw); err != nil {
			return
		}
		if cid := firstConversationID(raw); cid != "" && convId == "" {
			convId = cid
		}
		events := artifactState.ObserveRaw(raw, convId)
		emitSentinels(materializeArtifactEvents(client, account, convId, events, artifactConfig))
		if artifactState.LastAssistantMsgID != "" {
			assistantMessageID = artifactState.LastAssistantMsgID
		}
		if artifactState.ConversationID != "" && convId == "" {
			convId = artifactState.ConversationID
		}
	}
	emitThinking := func(delta string) {
		if delta == "" {
			return
		}
		thinkingText += delta
		emitSentinels([]map[string]interface{}{{
			"event": "thinking",
			"kind":  "analysis",
			"delta": delta,
		}})
		if stream {
			reasoningChunk := official_types.NewReasoningChunk(delta, model)
			if convId != "" {
				reasoningChunk.ConversationID = convId
			}
			c.Writer.WriteString("data: " + reasoningChunk.String() + "\n\n")
			c.Writer.Flush()
		}
	}
	finalizeArtifacts := func() {
		emitSentinels(materializeArtifactEvents(client, account, convId, artifactState.Finalize(), artifactConfig))
	}
readLoop:
	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			if err == io.EOF && line == "" {
				break
			}
			if err != io.EOF {
				return HandlerResult{}
			}
		}
		if eventName, ok := sseparser.EventName(line); ok {
			currentEvent = eventName
		}
		for _, line := range sseparser.DataPayloads(line) {
			if strings.HasPrefix(line, "[DONE]") {
				if shouldUseWebsocketHandoff(readingWebsocket, handoffTopicID, wsConn, previous_text.Text, imgSource) {
					wsReader, err := chatWebsocketStreamReader(wsConn, handoffTopicID)
					if err == nil {
						websocketStream = wsReader
						defer websocketStream.Close()
						reader = bufio.NewReader(wsReader)
						readingWebsocket = true
						currentEvent = ""
						continue readLoop
					}
				}
				finalizeArtifacts()
				break readLoop
			}
			observeArtifacts(line)
			if topicID, skip := sseparser.HandoffTopicFromPayload(line, currentEvent); skip {
				if topicID != "" {
					handoffTopicID = topicID
				}
				currentEvent = ""
				continue
			}
			streamEvent, ok := parseConversationEvent(line, &patchState, model)
			if os.Getenv("DEBUG_SSE") != "" {
				debugText := streamEvent.text
				debugSrc := "chunk"
				if streamEvent.response.Message.ID != "" {
					debugText = sseparser.FirstStringPart(streamEvent.response.Message.Content.Parts)
					debugSrc = "response"
				}
				raw := strings.TrimSpace(line)
				if len(raw) > 200 {
					raw = raw[:200] + "..."
				}
				fmt.Printf("[sse-in] src=%s channel=%q textLen=%d finish=%q parsed=%v raw=%q\n", debugSrc, streamEvent.channel, len(debugText), streamEvent.finishReason, ok, raw)
			}
			if !ok {
				currentEvent = ""
				continue
			}
			if streamEvent.chunk != nil {
				if streamEvent.conversationID != "" {
					convId = streamEvent.conversationID
				}
				if streamEvent.chunk.Sentinel != nil {
					sentinel = append(sentinel, streamEvent.chunk.Sentinel)
				}
				deltaText := sseparser.NormalizeContentDelta(previous_text.Text, streamEvent.text)
				if streamEvent.channel != "" {
					activeChannel = streamEvent.channel
				}
				if streamEvent.finishReason != "" {
					finish_reason = streamEvent.finishReason
					if finish_reason == "length" {
						max_tokens = true
					}
					isEnd = true
				}
				if activeChannel == "analysis" {
					emitThinking(streamEvent.text)
					if streamEvent.isStop {
						if stream {
							finalLine := official_types.StopChunkWithConversation(finish_reason, model, convId)
							c.Writer.WriteString("data: " + finalLine.String() + "\n\n")
							c.Writer.Flush()
						}
						if max_tokens && convId != "" && assistantMessageID != "" {
							finalizeArtifacts()
							return HandlerResult{
								Text:              strings.Join(imgSource, "") + previous_text.Text,
								ThinkingText:      thinkingText,
								ConversationID:    convId,
								ParentMessageID:   assistantMessageID,
								Sentinel:          sentinel,
								ArtifactSignals:   artifactState.Signals,
								SandboxArtifacts:  artifactState.SandboxArtifacts,
								PDFArtifacts:      artifactState.PDFArtifacts,
								GeneratedImageIDs: artifactState.ImageFileIDs,
								StopSent:          true,
								Continue: &ContinueInfo{
									ConversationID: convId,
									ParentID:       assistantMessageID,
								},
							}
						}
						finalizeArtifacts()
						return HandlerResult{
							Text:              strings.Join(imgSource, "") + previous_text.Text,
							ThinkingText:      thinkingText,
							ConversationID:    convId,
							ParentMessageID:   assistantMessageID,
							Sentinel:          sentinel,
							ArtifactSignals:   artifactState.Signals,
							SandboxArtifacts:  artifactState.SandboxArtifacts,
							PDFArtifacts:      artifactState.PDFArtifacts,
							GeneratedImageIDs: artifactState.ImageFileIDs,
							StopSent:          true,
						}
					}
					currentEvent = ""
					continue
				}
				if stream {
					outChunk := *streamEvent.chunk
					if len(outChunk.Choices) > 0 {
						outChunk.Choices[0].Delta.Content = deltaText
						if streamEvent.role == "" || !isRole {
							outChunk.Choices[0].Delta.Role = ""
						}
					}
					if streamEvent.isStop && outChunk.ConversationID == "" {
						outChunk.ConversationID = convId
					}
					shouldWrite := deltaText != "" ||
						(streamEvent.role != "" && isRole) ||
						streamEvent.chunk.Sentinel != nil ||
						streamEvent.isStop
					if shouldWrite {
						c.Writer.WriteString("data: " + outChunk.String() + "\n\n")
						c.Writer.Flush()
					}
					if streamEvent.role != "" && isRole {
						isRole = false
					}
				}
				if deltaText != "" {
					previous_text.Text += deltaText
				}
				if streamEvent.isStop {
					if max_tokens && convId != "" && assistantMessageID != "" {
						finalizeArtifacts()
						return HandlerResult{
							Text:              strings.Join(imgSource, "") + previous_text.Text,
							ThinkingText:      thinkingText,
							ConversationID:    convId,
							ParentMessageID:   assistantMessageID,
							Sentinel:          sentinel,
							ArtifactSignals:   artifactState.Signals,
							SandboxArtifacts:  artifactState.SandboxArtifacts,
							PDFArtifacts:      artifactState.PDFArtifacts,
							GeneratedImageIDs: artifactState.ImageFileIDs,
							StopSent:          true,
							Continue: &ContinueInfo{
								ConversationID: convId,
								ParentID:       assistantMessageID,
							},
						}
					}
					finalizeArtifacts()
					return HandlerResult{
						Text:              strings.Join(imgSource, "") + previous_text.Text,
						ThinkingText:      thinkingText,
						ConversationID:    convId,
						ParentMessageID:   assistantMessageID,
						Sentinel:          sentinel,
						ArtifactSignals:   artifactState.Signals,
						SandboxArtifacts:  artifactState.SandboxArtifacts,
						PDFArtifacts:      artifactState.PDFArtifacts,
						GeneratedImageIDs: artifactState.ImageFileIDs,
						StopSent:          true,
					}
				}
				currentEvent = ""
				continue
			}
			original_response = streamEvent.response
			if original_response.Error != nil {
				c.JSON(500, gin.H{"error": original_response.Error})
				return HandlerResult{}
			}
			sentinel = append(sentinel, sseparser.SentinelsFromResponse(original_response)...)
			if original_response.ConversationID != convId {
				if convId == "" {
					convId = original_response.ConversationID
				} else {
					continue
				}
			}
			if streamEvent.channel != "" {
				activeChannel = streamEvent.channel
			}
			if original_response.Message.ID != "" && (original_response.Message.Author.Role == "assistant" || original_response.Message.Author.Role == "tool") {
				assistantMessageID = original_response.Message.ID
			}
			if activeChannel == "analysis" {
				thinkingDelta := sseparser.NormalizeContentDelta(thinkingText, sseparser.FirstStringPart(original_response.Message.Content.Parts))
				emitThinking(thinkingDelta)
				currentEvent = ""
				continue
			}
			if !(original_response.Message.Author.Role == "assistant" || (original_response.Message.Author.Role == "tool" && original_response.Message.Content.ContentType != "text")) || original_response.Message.Content.Parts == nil {
				continue
			}
			if original_response.Message.Metadata.MessageType == "" && activeChannel != "final" {
				continue
			}
			if (original_response.Message.Metadata.MessageType != "next" && original_response.Message.Metadata.MessageType != "continue" && activeChannel != "final") || !strings.HasSuffix(original_response.Message.Content.ContentType, "text") {
				continue
			}
			if original_response.Message.EndTurn != nil {
				if waitSource {
					waitSource = false
				}
				isEnd = true
			}
			if len(original_response.Message.Metadata.Citations) != 0 {
				r := []rune(original_response.Message.Content.Parts[0].(string))
				if waitSource {
					if string(r[len(r)-1:]) == "】" {
						waitSource = false
					} else {
						continue
					}
				}
				offset := 0
				for _, citation := range original_response.Message.Metadata.Citations {
					rl := len(r)
					attr := urlAttrMap[citation.Metadata.URL]
					if attr == "" {
						u, _ := url.Parse(citation.Metadata.URL)
						BaseURL := u.Scheme + "://" + u.Host + "/"
						attr = getURLAttribution(client, account, BaseURL)
						if attr != "" {
							urlAttrMap[citation.Metadata.URL] = attr
						}
					}
					original_response.Message.Content.Parts[0] = string(r[:citation.StartIx+offset]) + " ([" + attr + "](" + citation.Metadata.URL + " \"" + citation.Metadata.Title + "\"))" + string(r[citation.EndIx+offset:])
					r = []rune(original_response.Message.Content.Parts[0].(string))
					offset += len(r) - rl
				}
			} else if waitSource {
				continue
			}
			response_string := ""
			if original_response.Message.Recipient != "all" {
				continue
			}
			if original_response.Message.Content.ContentType == "multimodal_text" {
				apiUrl := BaseURL + "/files/"
				if FILES_REVERSE_PROXY != "" {
					apiUrl = FILES_REVERSE_PROXY
				}
				imgSource = make([]string, len(original_response.Message.Content.Parts))
				var wg sync.WaitGroup
				for index, part := range original_response.Message.Content.Parts {
					jsonItem, _ := json.Marshal(part)
					var dalle_content chatgpt_types.DalleContent
					err = json.Unmarshal(jsonItem, &dalle_content)
					if err != nil {
						continue
					}
					url := apiUrl + strings.Split(dalle_content.AssetPointer, "//")[1] + "/download"
					wg.Add(1)
					go GetImageSource(client, &wg, url, dalle_content.Metadata.Dalle.Prompt, account, index, imgSource)
				}
				wg.Wait()
				translated_response := official_types.NewChatCompletionChunk(strings.Join(imgSource, ""), model)
				if isRole {
					translated_response.Choices[0].Delta.Role = original_response.Message.Author.Role
				}
				response_string = "data: " + translated_response.String() + "\n\n"
			}
			if response_string == "" {
				response_string = chatgpt.ConvertToString(&original_response, &previous_text, isRole, model)
			}
			if response_string == "" {
				if isEnd {
					goto endProcess
				} else {
					continue
				}
			}
			if response_string == "【" {
				waitSource = true
				continue
			}
		endProcess:
			isRole = false
			if stream {
				_, err = c.Writer.WriteString(response_string)
				if err != nil {
					return HandlerResult{}
				}
				c.Writer.Flush()
			}

			if original_response.Message.Metadata.FinishDetails != nil {
				if original_response.Message.Metadata.FinishDetails.Type == "max_tokens" {
					max_tokens = true
				}
				finish_reason = original_response.Message.Metadata.FinishDetails.Type
			}
			if isEnd {
				if stream {
					final_line := official_types.StopChunkWithConversation(finish_reason, model, convId)
					c.Writer.WriteString("data: " + final_line.String() + "\n\n")
					c.Writer.Flush()
				}
				finalizeArtifacts()
				return HandlerResult{
					Text:              strings.Join(imgSource, "") + previous_text.Text,
					ThinkingText:      thinkingText,
					ConversationID:    convId,
					ParentMessageID:   assistantMessageID,
					Sentinel:          sentinel,
					ArtifactSignals:   artifactState.Signals,
					SandboxArtifacts:  artifactState.SandboxArtifacts,
					PDFArtifacts:      artifactState.PDFArtifacts,
					GeneratedImageIDs: artifactState.ImageFileIDs,
					StopSent:          stream,
				}
			}
			currentEvent = ""
		}
		if err == io.EOF {
			break
		}
	}
	if !max_tokens {
		finalizeArtifacts()
		return HandlerResult{
			Text:              strings.Join(imgSource, "") + previous_text.Text,
			ThinkingText:      thinkingText,
			ConversationID:    convId,
			ParentMessageID:   assistantMessageID,
			Sentinel:          sentinel,
			ArtifactSignals:   artifactState.Signals,
			SandboxArtifacts:  artifactState.SandboxArtifacts,
			PDFArtifacts:      artifactState.PDFArtifacts,
			GeneratedImageIDs: artifactState.ImageFileIDs,
		}
	}
	finalizeArtifacts()
	return HandlerResult{
		Text:              strings.Join(imgSource, "") + previous_text.Text,
		ThinkingText:      thinkingText,
		ConversationID:    convId,
		ParentMessageID:   assistantMessageID,
		Sentinel:          sentinel,
		ArtifactSignals:   artifactState.Signals,
		SandboxArtifacts:  artifactState.SandboxArtifacts,
		PDFArtifacts:      artifactState.PDFArtifacts,
		GeneratedImageIDs: artifactState.ImageFileIDs,
		Continue: &ContinueInfo{
			ConversationID: original_response.ConversationID,
			ParentID:       original_response.Message.ID,
		},
	}
}