//! Cold start prompt generation for conversation-driven onboarding.
//!
//! Generates stage-specific system prompts that guide the agent through
//! the 6-phase cold start flow without requiring form-filling.

/// Cold start phases matching the frontend state machine.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ColdStartPhase {
    Idle,
    AgentGreeting,
    IndustryDiscovery,
    IdentitySetup,
    FirstTask,
    Completed,
}

impl ColdStartPhase {
    pub fn from_str(s: &str) -> Self {
        match s {
            "idle" => Self::Idle,
            "agent_greeting" => Self::AgentGreeting,
            "industry_discovery" => Self::IndustryDiscovery,
            "identity_setup" => Self::IdentitySetup,
            "first_task" => Self::FirstTask,
            "completed" => Self::Completed,
            _ => Self::Idle,
        }
    }
}

/// Industry-specific task suggestions for first_task phase.
struct IndustryTasks {
    tasks: &'static [(&'static str, &'static str)],
}

const HEALTHCARE_TASKS: IndustryTasks = IndustryTasks {
    tasks: &[
        ("排班查询", "今天有需要处理的排班问题吗？"),
        ("数据报表", "需要我帮你整理上周的数据报表吗？"),
        ("政策查询", "最近有医保政策变化需要了解吗？"),
    ],
};

const EDUCATION_TASKS: IndustryTasks = IndustryTasks {
    tasks: &[
        ("课程安排", "需要帮你安排下周的课程吗？"),
        ("成绩分析", "有学生成绩需要分析吗？"),
        ("测验生成", "需要帮学生出一份测验吗？告诉我科目和年级就行。"),
    ],
};

const GARMENT_TASKS: IndustryTasks = IndustryTasks {
    tasks: &[
        ("订单跟踪", "有需要跟踪的订单吗？"),
        ("生产排期", "需要安排生产计划吗？"),
        ("成本核算", "有需要核算的成本数据吗？"),
    ],
};

const ECOMMERCE_TASKS: IndustryTasks = IndustryTasks {
    tasks: &[
        ("库存检查", "需要检查库存情况吗？"),
        ("销售分析", "想看看最近的销售数据吗？"),
        ("商品文案", "有新商品需要写详情页吗？"),
    ],
}

;

/// Generate the cold start system prompt for a given phase and optional industry.
pub fn generate_cold_start_prompt(phase: ColdStartPhase, industry: Option<&str>) -> String {
    match phase {
        ColdStartPhase::Idle | ColdStartPhase::AgentGreeting => format!(
            "你是一个正在认识新用户的 AI 管家。\n\n\
             ## 当前任务\n\
             向用户打招呼并了解他们的工作。用简短自然的方式询问。\n\n\
             ## 规则\n\
             - 每条消息不超过 3 句话\n\
             - 不要问\"你的行业是什么\"，而是问\"你每天最常处理什么事？\"\n\
             - 保持热情友好，像一个新同事在打招呼\n\
             - 用中文交流"
        ),

        ColdStartPhase::IndustryDiscovery => {
            let industry_hint = match industry {
                Some("healthcare") => "用户可能从事医疗行政工作。",
                Some("education") => "用户可能从事教育培训工作。",
                Some("garment") => "用户可能从事制衣制造工作。",
                Some("ecommerce") => "用户可能从事电商零售工作。",
                _ => "继续了解用户的工作场景。",
            };
            format!(
                "你是一个正在了解用户工作场景的 AI 管家。\n\n\
                 ## 当前阶段：行业发现\n\
                 {industry_hint}\n\n\
                 ## 规则\n\
                 - 根据用户的回答确认行业\n\
                 - 如果检测到行业，主动说出你的理解，让用户确认\n\
                 - 每条消息不超过 3 句话\n\
                 - 用中文交流"
            )
        }

        ColdStartPhase::IdentitySetup => {
            let name_suggestion = match industry {
                Some("healthcare") => "小医",
                Some("education") => "小教",
                Some("garment") => "小织",
                Some("ecommerce") => "小商",
                _ => "小助手",
            };
            format!(
                "你是一个正在为自己起名字的 AI 管家。\n\n\
                 ## 当前阶段：身份设定\n\
                 根据你了解的行业信息，向用户提议一个合适的名字和沟通风格。\n\n\
                 ## 建议\n\
                 - 可以提议叫\"{name_suggestion}\"或其他合适的名字\n\
                 - 说明你选择的沟通风格（专业/亲切/简洁）\n\
                 - 让用户确认或提出自己的想法\n\
                 - 每条消息不超过 3 句话\n\
                 - 用中文交流"
            )
        }

        ColdStartPhase::FirstTask => {
            let task_prompt = match industry {
                Some("healthcare") => HEALTHCARE_TASKS.tasks[2].1,
                Some("education") => EDUCATION_TASKS.tasks[2].1,
                Some("garment") => GARMENT_TASKS.tasks[2].1,
                Some("ecommerce") => ECOMMERCE_TASKS.tasks[2].1,
                _ => "有什么我可以帮你的吗？",
            };
            format!(
                "你是一个 AI 管家，用户已经完成了初始设置。\n\n\
                 ## 当前阶段：首次任务引导\n\
                 引导用户完成第一个实际任务，让他们体验你的能力。\n\n\
                 ## 建议\n\
                 - {task_prompt}\n\
                 - 根据用户需求灵活调整\n\
                 - 保持简短，1-2 句话\n\
                 - 用中文交流"
            )
        }

        ColdStartPhase::Completed => String::new(),
    }
}

/// Check if a cold start prompt should be injected for the given phase.
pub fn should_inject_prompt(phase: ColdStartPhase) -> bool {
    !matches!(phase, ColdStartPhase::Idle | ColdStartPhase::Completed)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_phase_from_str() {
        assert_eq!(ColdStartPhase::from_str("idle"), ColdStartPhase::Idle);
        assert_eq!(ColdStartPhase::from_str("agent_greeting"), ColdStartPhase::AgentGreeting);
        assert_eq!(ColdStartPhase::from_str("industry_discovery"), ColdStartPhase::IndustryDiscovery);
        assert_eq!(ColdStartPhase::from_str("identity_setup"), ColdStartPhase::IdentitySetup);
        assert_eq!(ColdStartPhase::from_str("first_task"), ColdStartPhase::FirstTask);
        assert_eq!(ColdStartPhase::from_str("completed"), ColdStartPhase::Completed);
        assert_eq!(ColdStartPhase::from_str("unknown"), ColdStartPhase::Idle);
    }

    #[test]
    fn test_greeting_prompt_not_empty() {
        let prompt = generate_cold_start_prompt(ColdStartPhase::AgentGreeting, None);
        assert!(!prompt.is_empty());
        assert!(prompt.contains("AI 管家"));
    }

    #[test]
    fn test_industry_discovery_with_industry() {
        let prompt = generate_cold_start_prompt(ColdStartPhase::IndustryDiscovery, Some("healthcare"));
        assert!(prompt.contains("医疗行政"));
    }

    #[test]
    fn test_identity_setup_suggests_name() {
        let prompt = generate_cold_start_prompt(ColdStartPhase::IdentitySetup, Some("education"));
        assert!(prompt.contains("小教"));
    }

    #[test]
    fn test_first_task_has_suggestion() {
        let prompt = generate_cold_start_prompt(ColdStartPhase::FirstTask, Some("ecommerce"));
        assert!(!prompt.is_empty());
        assert!(prompt.contains("库存") || prompt.contains("销售") || prompt.contains("商品"));
    }

    #[test]
    fn test_completed_returns_empty() {
        let prompt = generate_cold_start_prompt(ColdStartPhase::Completed, None);
        assert!(prompt.is_empty());
    }

    #[test]
    fn test_should_inject() {
        assert!(!should_inject_prompt(ColdStartPhase::Idle));
        assert!(should_inject_prompt(ColdStartPhase::AgentGreeting));
        assert!(should_inject_prompt(ColdStartPhase::IndustryDiscovery));
        assert!(should_inject_prompt(ColdStartPhase::IdentitySetup));
        assert!(should_inject_prompt(ColdStartPhase::FirstTask));
        assert!(!should_inject_prompt(ColdStartPhase::Completed));
    }
}