use std::{error::Error, fmt};

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum AiTaskFieldError {
    MissingTaskId,
    MissingOwnerUserId,
    MissingRequestLabel,
    MissingSourceModule,
    MissingStageBlueprints,
    DuplicateStageBlueprint,
    MissingReferenceId,
    MissingChunkText,
    InvalidSequence,
    MissingFailureMessage,
    MissingStage,
    InvalidTaskState,
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum AiTaskServiceError {
    Field(AiTaskFieldError),
    TaskAlreadyExists,
    TaskNotFound,
    StageNotFound,
    Store(String),
}

impl fmt::Display for AiTaskFieldError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::MissingTaskId => f.write_str("ai_task.task_id 不能为空"),
            Self::MissingOwnerUserId => f.write_str("ai_task.owner_user_id 不能为空"),
            Self::MissingRequestLabel => f.write_str("ai_task.request_label 不能为空"),
            Self::MissingSourceModule => f.write_str("ai_task.source_module 不能为空"),
            Self::MissingStageBlueprints => f.write_str("ai_task.stages 至少需要一个有效阶段"),
            Self::DuplicateStageBlueprint => f.write_str("ai_task.stages 不能包含重复阶段"),
            Self::MissingReferenceId => f.write_str("ai_result_reference.reference_id 不能为空"),
            Self::MissingChunkText => f.write_str("ai_text_chunk.delta_text 不能为空"),
            Self::InvalidSequence => f.write_str("ai_text_chunk.sequence 必须大于 0"),
            Self::MissingFailureMessage => f.write_str("ai_task.failure_message 不能为空"),
            Self::MissingStage => f.write_str("ai_task.stage 不存在"),
            Self::InvalidTaskState => f.write_str("当前 ai_task 状态不允许执行该操作"),
        }
    }
}

impl Error for AiTaskFieldError {}

impl fmt::Display for AiTaskServiceError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Field(error) => write!(f, "{error}"),
            Self::TaskAlreadyExists => f.write_str("ai_task 已存在，不能重复创建"),
            Self::TaskNotFound => f.write_str("ai_task 不存在"),
            Self::StageNotFound => f.write_str("ai_task.stage 不存在"),
            Self::Store(message) => f.write_str(message),
        }
    }
}

impl Error for AiTaskServiceError {}