use std::sync::Arc;

use crate::{
    chat::models::{ChatMessageRequest, ChatMessageResponse},
    error::AppError,
    forms::{models::FormExtractRequest, service::FormService},
    jobs::{models::GenerateJobDescriptionRequest, service::JobsService},
    providers::{
        help_center::help_center_provider::HelpCenterProvider, llm::ai_provider::AiProvider,
    },
    tickets::{models::CreateTicketRequest, service::TicketService},
};

#[derive(Clone)]
pub struct ChatOrchestrator {
    jobs_service: JobsService,
    form_service: FormService,
    help_center: Arc<dyn HelpCenterProvider>,
    ticket_service: TicketService,
    ai_provider: Arc<dyn AiProvider>,
}

impl ChatOrchestrator {
    pub fn new(
        jobs_service: JobsService,
        form_service: FormService,
        help_center: Arc<dyn HelpCenterProvider>,
        ticket_service: TicketService,
        ai_provider: Arc<dyn AiProvider>,
    ) -> Self {
        Self {
            jobs_service,
            form_service,
            help_center,
            ticket_service,
            ai_provider,
        }
    }

    pub async fn handle_chat(
        &self,
        request: ChatMessageRequest,
    ) -> Result<ChatMessageResponse, AppError> {
        let intent = classify_intent(&request.message);
        let conversation_id = request.conversation_id.clone();

        match intent.as_str() {
            "job_description_generation" => {
                let jd = self
                    .jobs_service
                    .generate_description(GenerateJobDescriptionRequest {
                        role_title: request.message.clone(),
                        seniority: None,
                        department: None,
                        employment_type: None,
                        required_skills: vec!["communication".to_string()],
                        optional_skills: None,
                        responsibilities: None,
                        company_context: None,
                    })
                    .await?;

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: "Generated a draft job description.".to_string(),
                    data: serde_json::to_value(jd).unwrap_or(serde_json::Value::Null),
                    conversation_id: conversation_id.clone(),
                })
            }
            "form_filling_assistance" => {
                let extracted = self
                    .form_service
                    .extract(FormExtractRequest {
                        raw_user_input: request.message.clone(),
                        expected_fields: None,
                    })
                    .await?;

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: extracted.suggested_next_step.clone(),
                    data: serde_json::to_value(extracted).unwrap_or(serde_json::Value::Null),
                    conversation_id: conversation_id.clone(),
                })
            }
            "search_kb" => {
                let matches = self.help_center.search(&request.message).await?;
                let reply = if matches.is_empty() {
                    "No help article match found. Try rephrasing your question.".to_string()
                } else {
                    let mut response = format!("Found {} help article(s):\n\n", matches.len());
                    for (i, article) in matches.iter().take(5).enumerate() {
                        response.push_str(&format!("{}. **{}**\n{}\n\n", i + 1, article.title, article.summary));
                    }
                    if matches.len() > 5 {
                        response.push_str(&format!("...and {} more articles.", matches.len() - 5));
                    }
                    response
                };

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply,
                    data: serde_json::json!({ "matches": matches }),
                    conversation_id: conversation_id.clone(),
                })
            }
            "support_ticket_creation" => {
                let created = self
                    .ticket_service
                    .create(CreateTicketRequest {
                        subject: request.message.chars().take(80).collect::<String>(),
                        description: request.message.clone(),
                        priority: "medium".to_string(),
                        category: "general".to_string(),
                        user_id: request.user_id.unwrap_or_else(|| "anonymous".to_string()),
                        conversation_id: conversation_id.clone(),
                        source: Some("chatbot".to_string()),
                        tags: Some(vec!["chat".to_string()]),
                        metadata: None,
                    })
                    .await?;

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: format!("Support ticket created: {}. Our team will respond shortly.", created.ticket_id),
                    data: serde_json::to_value(created).unwrap_or(serde_json::Value::Null),
                    conversation_id: conversation_id.clone(),
                })
            }
            "explain_plan_limits" => {
                let reply = "Your AI plan determines how many AI actions you can use per month.\n\n\
                    - **Free AI**: 10 actions/month\n\
                    - **Starter AI**: 100 actions/month\n\
                    - **Growth AI**: 500 actions/month\n\
                    - **Pro AI**: 2000 actions/month\n\n\
                    You can purchase add-on packs for more usage. Would you like to upgrade your plan?";

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: reply.to_string(),
                    data: serde_json::json!({}),
                    conversation_id: conversation_id.clone(),
                })
            }
            "check_ai_pack_balance" => {
                let reply = "To check your AI balance, please visit the AI Usage section in your dashboard.\n\n\
                    You can view:\n\
                    - Monthly usage vs limit\n\
                    - Add-on balance remaining\n\
                    - Renewal date\n\n\
                    Would you like me to help with anything else?";

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: reply.to_string(),
                    data: serde_json::json!({}),
                    conversation_id: conversation_id.clone(),
                })
            }
            "generate_cover_letter" => {
                let reply = "I can help you generate a cover letter. Please provide:\n\
                    - The job title or position\n\
                    - Your key skills and experience\n\
                    - Any specific company or role details (optional)\n\n\
                    Or you can use the 'Generate Cover Letter' button on the job application page.";

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: reply.to_string(),
                    data: serde_json::json!({}),
                    conversation_id: conversation_id.clone(),
                })
            }
            "improve_resume_summary" => {
                let reply = "I can help improve your resume summary. Please share:\n\
                    - Your current resume summary (or paste it here)\n\
                    - The type of role you're targeting\n\
                    - Your key skills and experience\n\n\
                    Or you can use the 'Improve Resume' feature in your profile page.";

                Ok(ChatMessageResponse {
                    intent: intent.clone(),
                    reply: reply.to_string(),
                    data: serde_json::json!({}),
                    conversation_id: conversation_id.clone(),
                })
            }
            _ => {
                let generic = self
                    .ai_provider
                    .complete(
                        "You are Nxtgauge workflow assistant. Keep answers concise and actionable. If users ask about features, guide them to use the appropriate buttons or pages.",
                        &request.message,
                    )
                    .await?;

                Ok(ChatMessageResponse {
                    intent,
                    reply: generic,
                    data: serde_json::json!({}),
                    conversation_id: conversation_id.clone(),
                })
            }
        }
    }
}

fn classify_intent(message: &str) -> String {
    let text = message.to_lowercase();

    if text.contains("job description")
        || text.contains("generate job")
        || text.contains("create job")
        || text.contains("write job")
        || (text.contains("jd") && text.len() < 10)
    {
        return "job_description_generation".to_string();
    }

    if text.contains("cover letter")
        || text.contains("write a letter")
        || text.contains("generate letter")
    {
        return "generate_cover_letter".to_string();
    }

    if text.contains("resume")
        && (text.contains("improve")
            || text.contains("rewrite")
            || text.contains("summary")
            || text.contains("tailor"))
    {
        return "improve_resume_summary".to_string();
    }

    if text.contains("form") || text.contains("field") || text.contains("fill") {
        return "form_filling_assistance".to_string();
    }

    if text.contains("search kb")
        || text.contains("find article")
        || text.contains("how do i")
        || text.contains("how to")
        || text.contains("where do i")
        || (text.contains("help") && !text.contains("help me"))
        || text.contains("article")
        || text.contains("kb")
        || text.contains("docs")
        || text.contains("documentation")
    {
        return "search_kb".to_string();
    }

    if text.contains("ticket")
        || text.contains("support")
        || text.contains("issue")
        || text.contains("bug")
        || text.contains("problem")
        || text.contains("not working")
        || text.contains("error")
    {
        return "support_ticket_creation".to_string();
    }

    if text.contains("ai plan")
        || text.contains("ai limit")
        || text.contains("ai package")
        || text.contains("ai credit")
        || text.contains("upgrade ai")
    {
        return "explain_plan_limits".to_string();
    }

    if text.contains("balance")
        && (text.contains("ai") || text.contains("credit") || text.contains("action"))
    {
        return "check_ai_pack_balance".to_string();
    }

    "general".to_string()
}