/**
 * AI问答API工具函数
 */

// AI问答API基础配置
const AI_API_CONFIG = {
	baseURL: 'http://116.62.47.88:5003',
	timeout: 30000, // 30秒超时
	headers: {
		'Content-Type': 'application/json'
	}
};

/**
 * 发送AI问答请求（真正的流式处理）
 * @param {string} question - 用户问题
 * @param {Function} onChunk - 接收流式数据的回调函数
 * @returns {Promise} 返回Promise对象
 */
export const askAI = (question, onChunk = null) => {
	return new Promise((resolve, reject) => {
		// 参数验证
		if (!question || typeof question !== 'string' || !question.trim()) {
			reject(new Error('问题不能为空'));
			return;
		}

		// 构建请求参数
		const requestData = {
			question: question.trim()
		};

		// 发送请求
		uni.request({
			url: `${AI_API_CONFIG.baseURL}/ask`,
			method: 'POST',
			header: {
				...AI_API_CONFIG.headers,
				'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
			},
			data: requestData,
			timeout: AI_API_CONFIG.timeout,
			success: (response) => {
				// 检查响应状态
				if (response.statusCode === 200) {
					// 记录响应数据用于调试
					console.log('AI问答API响应数据:', response.data);
					console.log('响应数据类型:', typeof response.data);
					
					// 处理响应数据
					let responseText = '';
					
					// 如果是字符串，直接使用
					if (typeof response.data === 'string') {
						responseText = response.data;
						console.log('响应是字符串，长度:', responseText.length);
					} else if (response.data && typeof response.data === 'object') {
						// 如果是对象，尝试提取文本内容
						responseText = extractTextFromResponse(response.data);
						console.log('响应是对象，提取的文本:', responseText);
					}
					
					// 如果有回调函数，实现真正的流式效果
					if (onChunk && typeof onChunk === 'function') {
						console.log('开始真正的流式解析');
						// 立即开始解析，每解析到一个JSON对象就立即显示
						const fullText = parseAndStreamRealTime(responseText, onChunk);
						
						// 返回完整响应
						resolve({
							success: true,
							data: fullText,
							statusCode: response.statusCode
						});
					} else {
						// 直接解析完整文本
						const parsedText = parseConcatenatedJson(responseText);
						console.log('解析后的文本:', parsedText);
						
						resolve({
							success: true,
							data: parsedText,
							statusCode: response.statusCode
						});
					}
				} else {
					// 服务器错误
					reject({
						success: false,
						error: `服务器响应错误 (${response.statusCode})`,
						statusCode: response.statusCode,
						data: response.data
					});
				}
			},
			fail: (error) => {
				// 网络错误或其他错误
				console.error('AI问答API请求失败:', error);
				
				let errorMessage = '网络连接失败';
				if (error.errMsg) {
					if (error.errMsg.includes('timeout')) {
						errorMessage = '请求超时，请稍后重试';
					} else if (error.errMsg.includes('fail')) {
						errorMessage = '网络连接失败，请检查网络';
					}
				}
				
				reject({
					success: false,
					error: errorMessage,
					originalError: error
				});
			}
		});
	});
};

/**
 * 通过HTTP chunked实现真正的流式读取（H5下）
 * - 首选 fetch + ReadableStream
 * - 回退到 XMLHttpRequest + onprogress
 * @param {string} question 用户问题
 * @param {(chunkText:string, fullText:string)=>void} onChunk 块回调
 * @returns {Promise<{success:boolean,data?:string,error?:string}>}
 */
export const askAIStream = (question, onChunk) => {
    return new Promise(async (resolve, reject) => {
        if (!question || typeof question !== 'string' || !question.trim()) {
            reject(new Error('问题不能为空'));
            return;
        }

        const url = `${AI_API_CONFIG.baseURL}/ask`;
        const headers = {
            ...AI_API_CONFIG.headers,
            'Accept': 'text/event-stream, text/plain, text/html, application/json;q=0.9, */*;q=0.8',
            'Cache-Control': 'no-cache'
        };
        const body = JSON.stringify({ question: question.trim() });

        // 块处理：后端按 "\n\n" 分隔的 JSON 块，逐块解析并输出 chatText
        const emitByDoubleNewline = (state, emit) => {
            // 兼容 \r\n\r\n
            const delimiterRe = /\r?\n\r?\n/;
            const parts = state.buffer.split(delimiterRe);
            // 最后一段可能是不完整块，先不处理
            for (let i = 0; i < parts.length - 1; i++) {
                const part = (parts[i] || '').trim();
                if (!part) continue;
                try {
                    const obj = JSON.parse(part);
                    let piece = '';
                    if (obj && obj.response && typeof obj.response.chatText === 'string') {
                        piece = obj.response.chatText;
                    }
                    // 去掉思考标签，前端只显示可见内容
                    if (piece) {
                        const cleaned = piece.replace(/<think>/g, '').replace(/<\/think>/g, '');
                        emit(cleaned);
                        state.fullText += cleaned;
                    }
                } catch (e) {
                    // 块级解析失败，忽略该块或原样输出
                    // 为安全起见这里选择忽略，避免把JSON原文渲染到UI
                }
            }
            // 缓存尾段（不完整）
            state.buffer = parts[parts.length - 1] || '';
        };

        // H5 fetch 流式
        try {
            if (typeof window !== 'undefined' && window.fetch && typeof ReadableStream !== 'undefined') {
                const res = await fetch(url, { method: 'POST', headers, body });
                if (!res.ok) {
                    reject({ success: false, error: `服务器响应错误 (${res.status})` });
                    return;
                }
                const reader = res.body && res.body.getReader ? res.body.getReader() : null;
                if (!reader) {
                    // 无 reader 时，退化为一次性读取
                    const text = await res.text();
                    if (onChunk) onChunk(text, text);
                    resolve({ success: true, data: text });
                    return;
                }
                const decoder = new TextDecoder('utf-8');
                let done = false;
                const state = { buffer: '', fullText: '', thinking: false };
                while (!done) {
                    const { value, done: readerDone } = await reader.read();
                    done = readerDone;
                    if (value) {
                        const chunkText = decoder.decode(value, { stream: !done });
                        state.buffer += chunkText;
                        // 直接在此处解析并调用回调，保证 nowFull 不包含思考段的可见文本
                        const delimiterRe = /\r?\n\r?\n/;
                        const parts = state.buffer.split(delimiterRe);
                        for (let i = 0; i < parts.length - 1; i++) {
                            const part = (parts[i] || '').trim();
                            if (!part) continue;
                            try {
                                const obj = JSON.parse(part);
                                let piece = '';
                                if (obj && obj.response && typeof obj.response.chatText === 'string') {
                                    piece = obj.response.chatText;
                                }
                                const hasOpen = typeof piece === 'string' && piece.indexOf('<think>') > -1;
                                const hasClose = typeof piece === 'string' && piece.indexOf('</think>') > -1;
                                const cleaned = (piece || '').replace(/<think>/g, '').replace(/<\/think>/g, '');
                                const isThinkingPart = state.thinking || hasOpen; // 本块属于思考阶段
                                const addToFull = isThinkingPart ? '' : cleaned;
                                const computedNowFull = state.fullText + addToFull;
                                if (onChunk) onChunk(cleaned, computedNowFull, piece || '');
                                if (addToFull) state.fullText += addToFull;
                                // 更新思考状态：如果遇到关闭标签则退出思考
                                if (hasOpen) state.thinking = true;
                                if (hasClose) state.thinking = false;
                            } catch (e) {}
                        }
                        state.buffer = parts[parts.length - 1] || '';
                    }
                }
                // 读完后，尝试解析剩余缓冲
                if (state.buffer.trim()) {
                    try {
                        const obj = JSON.parse(state.buffer.trim());
                        let piece = '';
                        if (obj && obj.response && typeof obj.response.chatText === 'string') piece = obj.response.chatText;
                        if (piece) {
                            const hasOpen = typeof piece === 'string' && piece.indexOf('<think>') > -1;
                            const hasClose = typeof piece === 'string' && piece.indexOf('</think>') > -1;
                            const cleaned = piece.replace(/<think>/g, '').replace(/<\/think>/g, '');
                            const isThinkingPart = state.thinking || hasOpen;
                            const addToFull = isThinkingPart ? '' : cleaned;
                            onChunk && onChunk(cleaned, state.fullText + addToFull, piece);
                            if (addToFull) state.fullText += addToFull;
                            if (hasOpen) state.thinking = true;
                            if (hasClose) state.thinking = false;
                        }
                    } catch (_) {}
                }
                resolve({ success: true, data: state.fullText });
                return;
            }
        } catch (err) {
            console.warn('fetch流式失败，尝试XHR回退:', err);
        }

        // XHR 回退：利用 onprogress 增量读取
        try {
            const xhr = new XMLHttpRequest();
            xhr.open('POST', url, true);
            Object.keys(headers).forEach((k) => xhr.setRequestHeader(k, headers[k]));
            let lastLen = 0;
            const state = { buffer: '', fullText: '', thinking: false };
            xhr.onreadystatechange = () => {
                if (xhr.readyState === 4) {
                    if (xhr.status >= 200 && xhr.status < 300) {
                        // 完成时解析尾段
                        if (state.buffer.trim()) {
                            try {
                                const obj = JSON.parse(state.buffer.trim());
                                let piece = '';
                                if (obj && obj.response && typeof obj.response.chatText === 'string') piece = obj.response.chatText;
                                if (piece) {
                                    const hasOpen = typeof piece === 'string' && piece.indexOf('<think>') > -1;
                                    const hasClose = typeof piece === 'string' && piece.indexOf('</think>') > -1;
                                    const cleaned = piece.replace(/<think>/g, '').replace(/<\/think>/g, '');
                                    const isThinkingPart = state.thinking || hasOpen;
                                    const addToFull = isThinkingPart ? '' : cleaned;
                                    onChunk && onChunk(cleaned, state.fullText + addToFull, piece);
                                    if (addToFull) state.fullText += addToFull;
                                    if (hasOpen) state.thinking = true;
                                    if (hasClose) state.thinking = false;
                                }
                            } catch (_) {}
                        }
                        resolve({ success: true, data: state.fullText });
                    } else {
                        reject({ success: false, error: `服务器响应错误 (${xhr.status})` });
                    }
                }
            };
            xhr.onprogress = () => {
                const resp = xhr.responseText || '';
                if (resp.length > lastLen) {
                    const delta = resp.substring(lastLen);
                    lastLen = resp.length;
                    state.buffer += delta;
                    // 解析增量并过滤思考段对全文累积的影响
                    const delimiterRe = /\r?\n\r?\n/;
                    const parts = state.buffer.split(delimiterRe);
                    for (let i = 0; i < parts.length - 1; i++) {
                        const part = (parts[i] || '').trim();
                        if (!part) continue;
                        try {
                            const obj = JSON.parse(part);
                            let piece = '';
                            if (obj && obj.response && typeof obj.response.chatText === 'string') {
                                piece = obj.response.chatText;
                            }
                            const hasOpen = typeof piece === 'string' && piece.indexOf('<think>') > -1;
                            const hasClose = typeof piece === 'string' && piece.indexOf('</think>') > -1;
                            const cleaned = (piece || '').replace(/<think>/g, '').replace(/<\/think>/g, '');
                            const isThinkingPart = state.thinking || hasOpen;
                            const addToFull = isThinkingPart ? '' : cleaned;
                            const computedNowFull = state.fullText + addToFull;
                            if (onChunk) onChunk(cleaned, computedNowFull, piece || '');
                            if (addToFull) state.fullText += addToFull;
                            if (hasOpen) state.thinking = true;
                            if (hasClose) state.thinking = false;
                        } catch (e) {}
                    }
                    state.buffer = parts[parts.length - 1] || '';
                }
            };
            xhr.onerror = () => {
                reject({ success: false, error: '网络连接失败' });
            };
            xhr.send(body);
        } catch (err) {
            reject({ success: false, error: '请求发送失败' });
        }
    });
};

/**
 * 从响应对象中提取文本内容
 * @param {any} responseData - 响应数据
 * @returns {string} 提取的文本内容
 */
function extractTextFromResponse(responseData) {
	if (typeof responseData === 'string') {
		return responseData;
	}
	
	if (responseData && typeof responseData === 'object') {
		// 尝试提取各种可能的字段
		if (responseData.response && responseData.response.chatText) {
			return responseData.response.chatText;
		}
		if (responseData.text) {
			return responseData.text;
		}
		if (responseData.content) {
			return responseData.content;
		}
		if (responseData.message) {
			return responseData.message;
		}
		// 如果是数组，尝试处理第一个元素
		if (Array.isArray(responseData) && responseData.length > 0) {
			return extractTextFromResponse(responseData[0]);
		}
	}
	
	return '';
}

/**
 * 解析拼接的JSON对象字符串
 * @param {string} jsonString - 包含多个JSON对象的字符串
 * @returns {string} 提取的完整文本
 */
function parseConcatenatedJson(jsonString) {
	if (!jsonString || typeof jsonString !== 'string') {
		return '';
	}
	
	try {
		// 尝试直接解析为JSON
		const parsed = JSON.parse(jsonString);
		if (parsed && parsed.response && parsed.response.chatText) {
			return parsed.response.chatText;
		}
	} catch (e) {
		// 如果不是单个JSON对象，尝试解析拼接的JSON
		console.log('尝试解析拼接的JSON对象');
	}
	
	// 处理拼接的JSON对象
	let fullText = '';
	let currentIndex = 0;
	
	while (currentIndex < jsonString.length) {
		// 查找下一个JSON对象的开始位置
		const startBrace = jsonString.indexOf('{', currentIndex);
		if (startBrace === -1) break;
		
		// 查找对应的结束位置
		let braceCount = 0;
		let endBrace = -1;
		
		for (let i = startBrace; i < jsonString.length; i++) {
			if (jsonString[i] === '{') {
				braceCount++;
			} else if (jsonString[i] === '}') {
				braceCount--;
				if (braceCount === 0) {
					endBrace = i;
					break;
				}
			}
		}
		
		if (endBrace === -1) break;
		
		// 提取单个JSON对象
		const jsonObj = jsonString.substring(startBrace, endBrace + 1);
		
		try {
			const parsed = JSON.parse(jsonObj);
			if (parsed && parsed.response && parsed.response.chatText) {
				fullText += parsed.response.chatText;
			}
		} catch (e) {
			console.error('解析JSON对象失败:', e, jsonObj);
		}
		
		// 移动到下一个位置
		currentIndex = endBrace + 1;
	}
	
	return fullText;
}

/**
 * 实时解析并流式显示
 * @param {string} jsonString - 包含多个JSON对象的字符串
 * @param {Function} onChunk - 每解析到一个JSON对象就调用此回调
 * @returns {string} 提取的完整文本
 */
function parseAndStreamRealTime(jsonString, onChunk) {
	if (!jsonString || typeof jsonString !== 'string') {
		return '';
	}
	
	let fullText = '';
	let currentIndex = 0;
	
	while (currentIndex < jsonString.length) {
		// 查找下一个JSON对象的开始位置
		const startBrace = jsonString.indexOf('{', currentIndex);
		if (startBrace === -1) break;
		
		// 查找对应的结束位置
		let braceCount = 0;
		let endBrace = -1;
		
		for (let i = startBrace; i < jsonString.length; i++) {
			if (jsonString[i] === '{') {
				braceCount++;
			} else if (jsonString[i] === '}') {
				braceCount--;
				if (braceCount === 0) {
					endBrace = i;
					break;
				}
			}
		}
		
		if (endBrace === -1) break;
		
		// 提取单个JSON对象
		const jsonObj = jsonString.substring(startBrace, endBrace + 1);
		
		try {
			const parsed = JSON.parse(jsonObj);
			if (parsed && parsed.response && parsed.response.chatText) {
				const chunkText = parsed.response.chatText;
				fullText += chunkText;
				
				// 立即调用回调函数，实现实时显示
				console.log('实时解析到文本块:', chunkText, '当前完整文本:', fullText);
				onChunk(chunkText, fullText);
			}
		} catch (e) {
			console.error('解析JSON对象失败:', e, jsonObj);
		}
		
		// 移动到下一个位置
		currentIndex = endBrace + 1;
	}
	
	return fullText;
}

/**
 * 格式化AI回复内容
 * @param {any} content - AI回复的原始内容
 * @returns {string} 格式化后的内容
 */
export const formatAIResponse = (content) => {
	if (!content) {
		return '抱歉，我暂时无法回答您的问题。';
	}
	
	// 如果是字符串，直接返回
	if (typeof content === 'string') {
		return content.trim();
	}
	
	// 如果是对象，尝试提取文本内容
	if (typeof content === 'object') {
		// 处理response对象 - 这是API返回的主要格式
		if (content.response && content.response.chatText) {
			return content.response.chatText.trim();
		}
		// 处理其他可能的字段
		if (content.text) {
			return content.text.trim();
		}
		if (content.content) {
			return content.content.trim();
		}
		if (content.message) {
			return content.message.trim();
		}
		// 如果是数组，尝试处理第一个元素
		if (Array.isArray(content) && content.length > 0) {
			return formatAIResponse(content[0]);
		}
	}
	
	return '抱歉，我暂时无法回答您的问题。';
};

/**
 * 检查网络连接状态
 * @returns {Promise<boolean>} 返回网络是否可用
 */
export const checkNetworkStatus = () => {
	return new Promise((resolve) => {
		uni.getNetworkType({
			success: (res) => {
				const isConnected = res.networkType !== 'none';
				resolve(isConnected);
			},
			fail: () => {
				resolve(false);
			}
		});
	});
};

export default {
	askAI,
	formatAIResponse,
	checkNetworkStatus,
	askAIStream
};