use std::{
    fmt::Display,
    path::{Path, PathBuf},
};

use crate::{
    download::{download_url, save_b64},
    error::OpenAIError,
    types::InputSource,
    util::{create_all_dir, create_file_part},
};

use bytes::Bytes;

use super::{
    AudioInput, AudioResponseFormat, ChatCompletionFunctionCall, ChatCompletionFunctions,
    ChatCompletionNamedToolChoice, ChatCompletionRequestAssistantMessage,
    ChatCompletionRequestFunctionMessage, ChatCompletionRequestMessage,
    ChatCompletionRequestMessageContentPart, ChatCompletionRequestMessageContentPartImage,
    ChatCompletionRequestMessageContentPartText, ChatCompletionRequestSystemMessage,
    ChatCompletionRequestToolMessage, ChatCompletionRequestUserMessage,
    ChatCompletionRequestUserMessageContent, ChatCompletionToolChoiceOption, CreateFileRequest,
    CreateImageEditRequest, CreateImageVariationRequest, CreateMessageRequestContent,
    CreateSpeechResponse, CreateTranscriptionRequest, CreateTranslationRequest, DallE2ImageSize,
    EmbeddingInput, FileInput, FilePurpose, FunctionName, Image, ImageInput, ImageModel, ImageSize,
    ImageUrl, ImagesResponse, ModerationInput, Prompt, ResponseFormat, Role, Stop,
    TimestampGranularity,
};

/// for `impl_from!(T, Enum)`, implements
/// - `From<T>`
/// - `From<Vec<T>>`
/// - `From<&Vec<T>>`
/// - `From<[T; N]>`
/// - `From<&[T; N]>`
///
/// for `T: Into<String>` and `Enum` having variants `String(String)` and `StringArray(Vec<String>)`
macro_rules! impl_from {
    ($from_typ:ty, $to_typ:ty) => {
        // From<T> -> String variant
        impl From<$from_typ> for $to_typ {
            fn from(value: $from_typ) -> Self {
                <$to_typ>::String(value.into())
            }
        }

        // From<Vec<T>> -> StringArray variant
        impl From<Vec<$from_typ>> for $to_typ {
            fn from(value: Vec<$from_typ>) -> Self {
                <$to_typ>::StringArray(value.iter().map(|v| v.to_string()).collect())
            }
        }

        // From<&Vec<T>> -> StringArray variant
        impl From<&Vec<$from_typ>> for $to_typ {
            fn from(value: &Vec<$from_typ>) -> Self {
                <$to_typ>::StringArray(value.iter().map(|v| v.to_string()).collect())
            }
        }

        // From<[T; N]> -> StringArray variant
        impl<const N: usize> From<[$from_typ; N]> for $to_typ {
            fn from(value: [$from_typ; N]) -> Self {
                <$to_typ>::StringArray(value.into_iter().map(|v| v.to_string()).collect())
            }
        }

        // From<&[T; N]> -> StringArray variatn
        impl<const N: usize> From<&[$from_typ; N]> for $to_typ {
            fn from(value: &[$from_typ; N]) -> Self {
                <$to_typ>::StringArray(value.into_iter().map(|v| v.to_string()).collect())
            }
        }
    };
}

// From String "family" to Prompt
impl_from!(&str, Prompt);
impl_from!(String, Prompt);
impl_from!(&String, Prompt);

// From String "family" to Stop
impl_from!(&str, Stop);
impl_from!(String, Stop);
impl_from!(&String, Stop);

// From String "family" to ModerationInput
impl_from!(&str, ModerationInput);
impl_from!(String, ModerationInput);
impl_from!(&String, ModerationInput);

// From String "family" to EmbeddingInput
impl_from!(&str, EmbeddingInput);
impl_from!(String, EmbeddingInput);
impl_from!(&String, EmbeddingInput);

/// for `impl_default!(Enum)`, implements `Default` for `Enum` as `Enum::String("")` where `Enum` has `String` variant
macro_rules! impl_default {
    ($for_typ:ty) => {
        impl Default for $for_typ {
            fn default() -> Self {
                Self::String("".into())
            }
        }
    };
}

impl_default!(Prompt);
impl_default!(ModerationInput);
impl_default!(EmbeddingInput);

impl Default for InputSource {
    fn default() -> Self {
        InputSource::Path {
            path: PathBuf::new(),
        }
    }
}

/// for `impl_input!(Struct)` where
/// ```text
/// Struct {
///     source: InputSource
/// }
/// ```
/// implements methods `from_bytes` and `from_vec_u8`,
/// and `From<P>` for `P: AsRef<Path>`
macro_rules! impl_input {
    ($for_typ:ty) => {
        impl $for_typ {
            pub fn from_bytes(filename: String, bytes: Bytes) -> Self {
                Self {
                    source: InputSource::Bytes { filename, bytes },
                }
            }

            pub fn from_vec_u8(filename: String, vec: Vec<u8>) -> Self {
                Self {
                    source: InputSource::VecU8 { filename, vec },
                }
            }
        }

        impl<P: AsRef<Path>> From<P> for $for_typ {
            fn from(path: P) -> Self {
                let path_buf = path.as_ref().to_path_buf();
                Self {
                    source: InputSource::Path { path: path_buf },
                }
            }
        }
    };
}

impl_input!(AudioInput);
impl_input!(FileInput);
impl_input!(ImageInput);

impl Display for ImageSize {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                Self::S256x256 => "256x256",
                Self::S512x512 => "512x512",
                Self::S1024x1024 => "1024x1024",
                Self::S1792x1024 => "1792x1024",
                Self::S1024x1792 => "1024x1792",
            }
        )
    }
}

impl Display for DallE2ImageSize {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                Self::S256x256 => "256x256",
                Self::S512x512 => "512x512",
                Self::S1024x1024 => "1024x1024",
            }
        )
    }
}

impl Display for ImageModel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                Self::DallE2 => "dall-e-2",
                Self::DallE3 => "dall-e-3",
                Self::Other(other) => other,
            }
        )
    }
}

impl Display for ResponseFormat {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                ResponseFormat::Url => "url",
                ResponseFormat::B64Json => "b64_json",
            }
        )
    }
}

impl Display for AudioResponseFormat {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                AudioResponseFormat::Json => "json",
                AudioResponseFormat::Srt => "srt",
                AudioResponseFormat::Text => "text",
                AudioResponseFormat::VerboseJson => "verbose_json",
                AudioResponseFormat::Vtt => "vtt",
            }
        )
    }
}

impl Display for TimestampGranularity {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                TimestampGranularity::Word => "word",
                TimestampGranularity::Segment => "segment",
            }
        )
    }
}

impl Display for Role {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                Role::User => "user",
                Role::System => "system",
                Role::Assistant => "assistant",
                Role::Function => "function",
                Role::Tool => "tool",
            }
        )
    }
}

impl Display for FilePurpose {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                Self::Assistants => "assistants",
                Self::Batch => "batch",
                Self::FineTune => "fine-tune",
                Self::Vision => "vision",
            }
        )
    }
}

impl ImagesResponse {
    /// Save each image in a dedicated Tokio task and return paths to saved files.
    /// For [ResponseFormat::Url] each file is downloaded in dedicated Tokio task.
    pub async fn save<P: AsRef<Path>>(&self, dir: P) -> Result<Vec<PathBuf>, OpenAIError> {
        create_all_dir(dir.as_ref())?;

        let mut handles = vec![];
        for id in self.data.clone() {
            let dir_buf = PathBuf::from(dir.as_ref());
            handles.push(tokio::spawn(async move { id.save(dir_buf).await }));
        }

        let results = futures::future::join_all(handles).await;
        let mut errors = vec![];
        let mut paths = vec![];

        for result in results {
            match result {
                Ok(inner) => match inner {
                    Ok(path) => paths.push(path),
                    Err(e) => errors.push(e),
                },
                Err(e) => errors.push(OpenAIError::FileSaveError(e.to_string())),
            }
        }

        if errors.is_empty() {
            Ok(paths)
        } else {
            Err(OpenAIError::FileSaveError(
                errors
                    .into_iter()
                    .map(|e| e.to_string())
                    .collect::<Vec<String>>()
                    .join("; "),
            ))
        }
    }
}

impl CreateSpeechResponse {
    pub async fn save<P: AsRef<Path>>(&self, file_path: P) -> Result<(), OpenAIError> {
        let dir = file_path.as_ref().parent();

        if let Some(dir) = dir {
            create_all_dir(dir)?;
        }

        tokio::fs::write(file_path, &self.bytes)
            .await
            .map_err(|e| OpenAIError::FileSaveError(e.to_string()))?;

        Ok(())
    }
}

impl Image {
    async fn save<P: AsRef<Path>>(&self, dir: P) -> Result<PathBuf, OpenAIError> {
        match self {
            Image::Url { url, .. } => download_url(url, dir).await,
            Image::B64Json { b64_json, .. } => save_b64(b64_json, dir).await,
        }
    }
}

macro_rules! impl_from_for_integer_array {
    ($from_typ:ty, $to_typ:ty) => {
        impl<const N: usize> From<[$from_typ; N]> for $to_typ {
            fn from(value: [$from_typ; N]) -> Self {
                Self::IntegerArray(value.to_vec())
            }
        }

        impl<const N: usize> From<&[$from_typ; N]> for $to_typ {
            fn from(value: &[$from_typ; N]) -> Self {
                Self::IntegerArray(value.to_vec())
            }
        }

        impl From<Vec<$from_typ>> for $to_typ {
            fn from(value: Vec<$from_typ>) -> Self {
                Self::IntegerArray(value)
            }
        }

        impl From<&Vec<$from_typ>> for $to_typ {
            fn from(value: &Vec<$from_typ>) -> Self {
                Self::IntegerArray(value.clone())
            }
        }
    };
}

impl_from_for_integer_array!(u32, EmbeddingInput);
impl_from_for_integer_array!(u16, Prompt);

macro_rules! impl_from_for_array_of_integer_array {
    ($from_typ:ty, $to_typ:ty) => {
        impl From<Vec<Vec<$from_typ>>> for $to_typ {
            fn from(value: Vec<Vec<$from_typ>>) -> Self {
                Self::ArrayOfIntegerArray(value)
            }
        }

        impl From<&Vec<Vec<$from_typ>>> for $to_typ {
            fn from(value: &Vec<Vec<$from_typ>>) -> Self {
                Self::ArrayOfIntegerArray(value.clone())
            }
        }

        impl<const M: usize, const N: usize> From<[[$from_typ; N]; M]> for $to_typ {
            fn from(value: [[$from_typ; N]; M]) -> Self {
                Self::ArrayOfIntegerArray(value.iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const M: usize, const N: usize> From<[&[$from_typ; N]; M]> for $to_typ {
            fn from(value: [&[$from_typ; N]; M]) -> Self {
                Self::ArrayOfIntegerArray(value.iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const M: usize, const N: usize> From<&[[$from_typ; N]; M]> for $to_typ {
            fn from(value: &[[$from_typ; N]; M]) -> Self {
                Self::ArrayOfIntegerArray(value.iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const M: usize, const N: usize> From<&[&[$from_typ; N]; M]> for $to_typ {
            fn from(value: &[&[$from_typ; N]; M]) -> Self {
                Self::ArrayOfIntegerArray(value.iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const N: usize> From<[Vec<$from_typ>; N]> for $to_typ {
            fn from(value: [Vec<$from_typ>; N]) -> Self {
                Self::ArrayOfIntegerArray(value.to_vec())
            }
        }

        impl<const N: usize> From<&[Vec<$from_typ>; N]> for $to_typ {
            fn from(value: &[Vec<$from_typ>; N]) -> Self {
                Self::ArrayOfIntegerArray(value.to_vec())
            }
        }

        impl<const N: usize> From<[&Vec<$from_typ>; N]> for $to_typ {
            fn from(value: [&Vec<$from_typ>; N]) -> Self {
                Self::ArrayOfIntegerArray(value.into_iter().map(|inner| inner.clone()).collect())
            }
        }

        impl<const N: usize> From<&[&Vec<$from_typ>; N]> for $to_typ {
            fn from(value: &[&Vec<$from_typ>; N]) -> Self {
                Self::ArrayOfIntegerArray(
                    value
                        .to_vec()
                        .into_iter()
                        .map(|inner| inner.clone())
                        .collect(),
                )
            }
        }

        impl<const N: usize> From<Vec<[$from_typ; N]>> for $to_typ {
            fn from(value: Vec<[$from_typ; N]>) -> Self {
                Self::ArrayOfIntegerArray(value.into_iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const N: usize> From<&Vec<[$from_typ; N]>> for $to_typ {
            fn from(value: &Vec<[$from_typ; N]>) -> Self {
                Self::ArrayOfIntegerArray(value.into_iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const N: usize> From<Vec<&[$from_typ; N]>> for $to_typ {
            fn from(value: Vec<&[$from_typ; N]>) -> Self {
                Self::ArrayOfIntegerArray(value.into_iter().map(|inner| inner.to_vec()).collect())
            }
        }

        impl<const N: usize> From<&Vec<&[$from_typ; N]>> for $to_typ {
            fn from(value: &Vec<&[$from_typ; N]>) -> Self {
                Self::ArrayOfIntegerArray(value.into_iter().map(|inner| inner.to_vec()).collect())
            }
        }
    };
}

impl_from_for_array_of_integer_array!(u32, EmbeddingInput);
impl_from_for_array_of_integer_array!(u16, Prompt);

impl From<&str> for ChatCompletionFunctionCall {
    fn from(value: &str) -> Self {
        match value {
            "auto" => Self::Auto,
            "none" => Self::None,
            _ => Self::Function { name: value.into() },
        }
    }
}

impl From<&str> for FunctionName {
    fn from(value: &str) -> Self {
        Self { name: value.into() }
    }
}

impl From<String> for FunctionName {
    fn from(value: String) -> Self {
        Self { name: value }
    }
}

impl From<&str> for ChatCompletionNamedToolChoice {
    fn from(value: &str) -> Self {
        Self {
            r#type: super::ChatCompletionToolType::Function,
            function: value.into(),
        }
    }
}

impl From<String> for ChatCompletionNamedToolChoice {
    fn from(value: String) -> Self {
        Self {
            r#type: super::ChatCompletionToolType::Function,
            function: value.into(),
        }
    }
}

impl From<&str> for ChatCompletionToolChoiceOption {
    fn from(value: &str) -> Self {
        match value {
            "auto" => Self::Auto,
            "none" => Self::None,
            _ => Self::Named(value.into()),
        }
    }
}

impl From<String> for ChatCompletionToolChoiceOption {
    fn from(value: String) -> Self {
        match value.as_str() {
            "auto" => Self::Auto,
            "none" => Self::None,
            _ => Self::Named(value.into()),
        }
    }
}

impl From<(String, serde_json::Value)> for ChatCompletionFunctions {
    fn from(value: (String, serde_json::Value)) -> Self {
        Self {
            name: value.0,
            description: None,
            parameters: value.1,
        }
    }
}

impl From<ChatCompletionRequestUserMessage> for ChatCompletionRequestMessage {
    fn from(value: ChatCompletionRequestUserMessage) -> Self {
        Self::User(value)
    }
}

impl From<ChatCompletionRequestSystemMessage> for ChatCompletionRequestMessage {
    fn from(value: ChatCompletionRequestSystemMessage) -> Self {
        Self::System(value)
    }
}

impl From<ChatCompletionRequestAssistantMessage> for ChatCompletionRequestMessage {
    fn from(value: ChatCompletionRequestAssistantMessage) -> Self {
        Self::Assistant(value)
    }
}

impl From<ChatCompletionRequestFunctionMessage> for ChatCompletionRequestMessage {
    fn from(value: ChatCompletionRequestFunctionMessage) -> Self {
        Self::Function(value)
    }
}

impl From<ChatCompletionRequestToolMessage> for ChatCompletionRequestMessage {
    fn from(value: ChatCompletionRequestToolMessage) -> Self {
        Self::Tool(value)
    }
}

impl From<&str> for ChatCompletionRequestUserMessageContent {
    fn from(value: &str) -> Self {
        ChatCompletionRequestUserMessageContent::Text(value.into())
    }
}

impl From<String> for ChatCompletionRequestUserMessageContent {
    fn from(value: String) -> Self {
        ChatCompletionRequestUserMessageContent::Text(value)
    }
}

impl From<Vec<ChatCompletionRequestMessageContentPart>>
    for ChatCompletionRequestUserMessageContent
{
    fn from(value: Vec<ChatCompletionRequestMessageContentPart>) -> Self {
        ChatCompletionRequestUserMessageContent::Array(value)
    }
}

impl From<ChatCompletionRequestMessageContentPartText> for ChatCompletionRequestMessageContentPart {
    fn from(value: ChatCompletionRequestMessageContentPartText) -> Self {
        ChatCompletionRequestMessageContentPart::Text(value)
    }
}

impl From<ChatCompletionRequestMessageContentPartImage>
    for ChatCompletionRequestMessageContentPart
{
    fn from(value: ChatCompletionRequestMessageContentPartImage) -> Self {
        ChatCompletionRequestMessageContentPart::ImageUrl(value)
    }
}

impl From<&str> for ChatCompletionRequestMessageContentPartText {
    fn from(value: &str) -> Self {
        ChatCompletionRequestMessageContentPartText { text: value.into() }
    }
}

impl From<String> for ChatCompletionRequestMessageContentPartText {
    fn from(value: String) -> Self {
        ChatCompletionRequestMessageContentPartText { text: value }
    }
}

impl From<&str> for ImageUrl {
    fn from(value: &str) -> Self {
        Self {
            url: value.into(),
            detail: Default::default(),
        }
    }
}

impl From<String> for ImageUrl {
    fn from(value: String) -> Self {
        Self {
            url: value,
            detail: Default::default(),
        }
    }
}

impl From<String> for CreateMessageRequestContent {
    fn from(value: String) -> Self {
        Self::Content(value)
    }
}

impl From<&str> for CreateMessageRequestContent {
    fn from(value: &str) -> Self {
        Self::Content(value.to_string())
    }
}

impl Default for ChatCompletionRequestUserMessageContent {
    fn default() -> Self {
        ChatCompletionRequestUserMessageContent::Text("".into())
    }
}

impl Default for CreateMessageRequestContent {
    fn default() -> Self {
        Self::Content("".into())
    }
}

// start: types to multipart from

#[async_convert::async_trait]
impl async_convert::TryFrom<CreateTranscriptionRequest> for reqwest::multipart::Form {
    type Error = OpenAIError;

    async fn try_from(request: CreateTranscriptionRequest) -> Result<Self, Self::Error> {
        let audio_part = create_file_part(request.file.source).await?;

        let mut form = reqwest::multipart::Form::new()
            .part("file", audio_part)
            .text("model", request.model);

        if let Some(prompt) = request.prompt {
            form = form.text("prompt", prompt);
        }

        if let Some(response_format) = request.response_format {
            form = form.text("response_format", response_format.to_string())
        }

        if let Some(temperature) = request.temperature {
            form = form.text("temperature", temperature.to_string())
        }

        if let Some(language) = request.language {
            form = form.text("language", language);
        }

        if let Some(timestamp_granularities) = request.timestamp_granularities {
            for tg in timestamp_granularities {
                form = form.text("timestamp_granularities[]", tg.to_string());
            }
        }

        Ok(form)
    }
}

#[async_convert::async_trait]
impl async_convert::TryFrom<CreateTranslationRequest> for reqwest::multipart::Form {
    type Error = OpenAIError;

    async fn try_from(request: CreateTranslationRequest) -> Result<Self, Self::Error> {
        let audio_part = create_file_part(request.file.source).await?;

        let mut form = reqwest::multipart::Form::new()
            .part("file", audio_part)
            .text("model", request.model);

        if let Some(prompt) = request.prompt {
            form = form.text("prompt", prompt);
        }

        if let Some(response_format) = request.response_format {
            form = form.text("response_format", response_format.to_string())
        }

        if let Some(temperature) = request.temperature {
            form = form.text("temperature", temperature.to_string())
        }
        Ok(form)
    }
}

#[async_convert::async_trait]
impl async_convert::TryFrom<CreateImageEditRequest> for reqwest::multipart::Form {
    type Error = OpenAIError;

    async fn try_from(request: CreateImageEditRequest) -> Result<Self, Self::Error> {
        let image_part = create_file_part(request.image.source).await?;

        let mut form = reqwest::multipart::Form::new()
            .part("image", image_part)
            .text("prompt", request.prompt);

        if let Some(mask) = request.mask {
            let mask_part = create_file_part(mask.source).await?;
            form = form.part("mask", mask_part);
        }

        if let Some(model) = request.model {
            form = form.text("model", model.to_string())
        }

        if request.n.is_some() {
            form = form.text("n", request.n.unwrap().to_string())
        }

        if request.size.is_some() {
            form = form.text("size", request.size.unwrap().to_string())
        }

        if request.response_format.is_some() {
            form = form.text(
                "response_format",
                request.response_format.unwrap().to_string(),
            )
        }

        if request.user.is_some() {
            form = form.text("user", request.user.unwrap())
        }
        Ok(form)
    }
}

#[async_convert::async_trait]
impl async_convert::TryFrom<CreateImageVariationRequest> for reqwest::multipart::Form {
    type Error = OpenAIError;

    async fn try_from(request: CreateImageVariationRequest) -> Result<Self, Self::Error> {
        let image_part = create_file_part(request.image.source).await?;

        let mut form = reqwest::multipart::Form::new().part("image", image_part);

        if let Some(model) = request.model {
            form = form.text("model", model.to_string())
        }

        if request.n.is_some() {
            form = form.text("n", request.n.unwrap().to_string())
        }

        if request.size.is_some() {
            form = form.text("size", request.size.unwrap().to_string())
        }

        if request.response_format.is_some() {
            form = form.text(
                "response_format",
                request.response_format.unwrap().to_string(),
            )
        }

        if request.user.is_some() {
            form = form.text("user", request.user.unwrap())
        }
        Ok(form)
    }
}

#[async_convert::async_trait]
impl async_convert::TryFrom<CreateFileRequest> for reqwest::multipart::Form {
    type Error = OpenAIError;

    async fn try_from(request: CreateFileRequest) -> Result<Self, Self::Error> {
        let file_part = create_file_part(request.file.source).await?;
        let form = reqwest::multipart::Form::new()
            .part("file", file_part)
            .text("purpose", request.purpose.to_string());
        Ok(form)
    }
}

// end: types to multipart form