use axum::{
    extract::{Multipart, Path, State},
    http::StatusCode,
    response::{Html, IntoResponse, Json},
};
use serde_json::json;

use crate::{
    models::{EmoteResponse, UpdateEmoteRequest},
    AppState,
};

/// GET /
/// Serves an HTML page that dynamically loads and displays emotes from /json.
pub async fn root() -> impl IntoResponse {
    Html(include_str!("../templates/index.html"))
}

/// GET /json
/// Returns all emotes formatted as {"emotes": [...]}.
pub async fn list_emotes(State(state): State<AppState>) -> impl IntoResponse {
    match state.db.list_emotes().await {
        Ok(rows) => {
            let emotes: Vec<EmoteResponse> = rows
                .into_iter()
                .map(|row| EmoteResponse {
                    name: row.name.clone(),
                    url: state.storage.public_url(&row.image_key),
                    created: row.created_dt(),
                    modified: row.modified_dt(),
                })
                .collect();
            (StatusCode::OK, Json(json!({"emotes": emotes}))).into_response()
        }
        Err(e) => {
            tracing::error!("Failed to list emotes: {e}");
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to list emotes"})),
            )
                .into_response()
        }
    }
}

/// POST /emotes
/// Create a new emote. Accepts multipart/form-data with:
///   - `name`      (text)
///   - `alias`     (text, optional)
///   - `file`      (binary – the emote image)
pub async fn create_emote(
    State(state): State<AppState>,
    mut multipart: Multipart,
) -> impl IntoResponse {
    let mut name: Option<String> = None;
    let mut alias: Option<String> = None;
    let mut file_bytes: Option<bytes::Bytes> = None;
    let mut file_name: Option<String> = None;
    let mut content_type: Option<String> = None;

    while let Ok(Some(field)) = multipart.next_field().await {
        match field.name() {
            Some("name") => {
                name = field.text().await.ok();
            }
            Some("alias") => {
                alias = field.text().await.ok();
            }
            Some("file") => {
                file_name = field.file_name().map(|s| s.to_string());
                content_type = field.content_type().map(|s| s.to_string());
                file_bytes = field.bytes().await.ok();
            }
            _ => {}
        }
    }

    let name = match name {
        Some(n) if !n.is_empty() => n,
        _ => {
            return (
                StatusCode::BAD_REQUEST,
                Json(json!({"error": "Missing required field: name"})),
            )
                .into_response();
        }
    };

    let (bytes, fname) = match (file_bytes, file_name) {
        (Some(b), Some(n)) => (b, n),
        _ => {
            return (
                StatusCode::BAD_REQUEST,
                Json(json!({"error": "Missing required field: file"})),
            )
                .into_response();
        }
    };

    let ct = content_type
        .unwrap_or_else(|| mime_guess::from_path(&fname).first_or_octet_stream().to_string());

    let key = format!("emoji/{fname}");

    match state.storage.upload(&key, bytes, &ct).await {
        Ok(_) => {}
        Err(e) => {
            tracing::error!("S3 upload failed: {e}");
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to upload image"})),
            )
                .into_response();
        }
    }

    match state
        .db
        .create_emote(&name, alias.as_deref(), &key)
        .await
    {
        Ok(row) => {
            let url = state.storage.public_url(&row.image_key);
            let created = row.created_dt();
            let modified = row.modified_dt();
            let resp = EmoteResponse {
                name: row.name,
                url,
                created,
                modified,
            };
            (StatusCode::CREATED, Json(json!(resp))).into_response()
        }
        Err(e) => {
            tracing::error!("DB insert failed: {e}");
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to create emote"})),
            )
                .into_response()
        }
    }
}

/// PUT /emotes/:uuid
/// Update an existing emote's metadata.
/// Accepts JSON body with optional fields: `name`, `alias`, `image_key`.
pub async fn update_emote(
    State(state): State<AppState>,
    Path(uuid): Path<String>,
    Json(payload): Json<UpdateEmoteRequest>,
) -> impl IntoResponse {
    let alias_update: Option<Option<&str>> = payload.alias.as_ref().map(|a| Some(a.as_str()));

    match state
        .db
        .update_emote(
            &uuid,
            payload.name.as_deref(),
            alias_update,
            payload.image_key.as_deref(),
        )
        .await
    {
        Ok(Some(row)) => {
            let url = state.storage.public_url(&row.image_key);
            let created = row.created_dt();
            let modified = row.modified_dt();
            let resp = EmoteResponse {
                name: row.name,
                url,
                created,
                modified,
            };
            (StatusCode::OK, Json(json!(resp))).into_response()
        }
        Ok(None) => (
            StatusCode::NOT_FOUND,
            Json(json!({"error": "Emote not found"})),
        )
            .into_response(),
        Err(e) => {
            tracing::error!("DB update failed: {e}");
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to update emote"})),
            )
                .into_response()
        }
    }
}

/// DELETE /emotes/:uuid
/// Delete an emote and its associated image from S3.
pub async fn delete_emote(
    State(state): State<AppState>,
    Path(uuid): Path<String>,
) -> impl IntoResponse {
    // Fetch the row first so we can clean up S3.
    let row = match state.db.get_emote_by_id(&uuid).await {
        Ok(Some(r)) => r,
        Ok(None) => {
            return (
                StatusCode::NOT_FOUND,
                Json(json!({"error": "Emote not found"})),
            )
                .into_response();
        }
        Err(e) => {
            tracing::error!("DB fetch failed: {e}");
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to fetch emote"})),
            )
                .into_response();
        }
    };

    // Delete from S3 (best-effort – don't abort if this fails).
    if let Err(e) = state.storage.delete(&row.image_key).await {
        tracing::warn!("S3 delete failed for key {}: {e}", row.image_key);
    }

    match state.db.delete_emote(&uuid).await {
        Ok(true) => (StatusCode::NO_CONTENT).into_response(),
        Ok(false) => (
            StatusCode::NOT_FOUND,
            Json(json!({"error": "Emote not found"})),
        )
            .into_response(),
        Err(e) => {
            tracing::error!("DB delete failed: {e}");
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "Failed to delete emote"})),
            )
                .into_response()
        }
    }
}