use axum::{Json, extract::State};
use serde::{Deserialize, Serialize};
use tracing::{error, warn};
use tranquil_pds::api::error::{ApiError, DbResultExt};
use tranquil_pds::auth::{Admin, Auth};
use tranquil_pds::state::AppState;
use tranquil_types::CidLink;

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct ServerConfigOutput {
    pub server_name: String,
    pub primary_color: Option<String>,
    pub primary_color_dark: Option<String>,
    pub secondary_color: Option<String>,
    pub secondary_color_dark: Option<String>,
    pub logo_cid: Option<String>,
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct UpdateServerConfigRequest {
    pub server_name: Option<String>,
    pub primary_color: Option<String>,
    pub primary_color_dark: Option<String>,
    pub secondary_color: Option<String>,
    pub secondary_color_dark: Option<String>,
    pub logo_cid: Option<String>,
}

#[derive(Serialize)]
pub struct UpdateServerConfigOutput {
    pub success: bool,
}

fn is_valid_hex_color(s: &str) -> bool {
    if s.len() != 7 || !s.starts_with('#') {
        return false;
    }
    s[1..].chars().all(|c| c.is_ascii_hexdigit())
}

pub async fn get_server_config(
    State(state): State<AppState>,
) -> Result<Json<ServerConfigOutput>, ApiError> {
    let keys = &[
        "server_name",
        "primary_color",
        "primary_color_dark",
        "secondary_color",
        "secondary_color_dark",
        "logo_cid",
    ];

    let rows = state
        .repos
        .infra
        .get_server_configs(keys)
        .await
        .log_db_err("fetching server config")?;

    let config_map: std::collections::HashMap<String, String> = rows.into_iter().collect();

    Ok(Json(ServerConfigOutput {
        server_name: config_map
            .get("server_name")
            .cloned()
            .unwrap_or_else(|| "Tranquil PDS".to_string()),
        primary_color: config_map.get("primary_color").cloned(),
        primary_color_dark: config_map.get("primary_color_dark").cloned(),
        secondary_color: config_map.get("secondary_color").cloned(),
        secondary_color_dark: config_map.get("secondary_color_dark").cloned(),
        logo_cid: config_map.get("logo_cid").cloned(),
    }))
}

pub async fn update_server_config(
    State(state): State<AppState>,
    _auth: Auth<Admin>,
    Json(req): Json<UpdateServerConfigRequest>,
) -> Result<Json<UpdateServerConfigOutput>, ApiError> {
    if let Some(server_name) = req.server_name {
        let trimmed = server_name.trim();
        if trimmed.is_empty() || trimmed.len() > 100 {
            return Err(ApiError::InvalidRequest(
                "Server name must be 1-100 characters".into(),
            ));
        }
        state
            .repos
            .infra
            .upsert_server_config("server_name", trimmed)
            .await
            .log_db_err("upserting server_name")?;
    }

    if let Some(ref color) = req.primary_color {
        if color.is_empty() {
            state
                .repos
                .infra
                .delete_server_config("primary_color")
                .await
                .log_db_err("deleting primary_color")?;
        } else if is_valid_hex_color(color) {
            state
                .repos
                .infra
                .upsert_server_config("primary_color", color)
                .await
                .log_db_err("upserting primary_color")?;
        } else {
            return Err(ApiError::InvalidRequest(
                "Invalid primary color format (expected #RRGGBB)".into(),
            ));
        }
    }

    if let Some(ref color) = req.primary_color_dark {
        if color.is_empty() {
            state
                .repos
                .infra
                .delete_server_config("primary_color_dark")
                .await
                .log_db_err("deleting primary_color_dark")?;
        } else if is_valid_hex_color(color) {
            state
                .repos
                .infra
                .upsert_server_config("primary_color_dark", color)
                .await
                .log_db_err("upserting primary_color_dark")?;
        } else {
            return Err(ApiError::InvalidRequest(
                "Invalid primary dark color format (expected #RRGGBB)".into(),
            ));
        }
    }

    if let Some(ref color) = req.secondary_color {
        if color.is_empty() {
            state
                .repos
                .infra
                .delete_server_config("secondary_color")
                .await
                .log_db_err("deleting secondary_color")?;
        } else if is_valid_hex_color(color) {
            state
                .repos
                .infra
                .upsert_server_config("secondary_color", color)
                .await
                .log_db_err("upserting secondary_color")?;
        } else {
            return Err(ApiError::InvalidRequest(
                "Invalid secondary color format (expected #RRGGBB)".into(),
            ));
        }
    }

    if let Some(ref color) = req.secondary_color_dark {
        if color.is_empty() {
            state
                .repos
                .infra
                .delete_server_config("secondary_color_dark")
                .await
                .log_db_err("deleting secondary_color_dark")?;
        } else if is_valid_hex_color(color) {
            state
                .repos
                .infra
                .upsert_server_config("secondary_color_dark", color)
                .await
                .log_db_err("upserting secondary_color_dark")?;
        } else {
            return Err(ApiError::InvalidRequest(
                "Invalid secondary dark color format (expected #RRGGBB)".into(),
            ));
        }
    }

    if let Some(ref logo_cid) = req.logo_cid {
        let old_logo_cid = state
            .repos
            .infra
            .get_server_config("logo_cid")
            .await
            .ok()
            .flatten();

        let should_delete_old = match (&old_logo_cid, logo_cid.is_empty()) {
            (Some(old), true) => Some(old.clone()),
            (Some(old), false) if old != logo_cid => Some(old.clone()),
            _ => None,
        };

        if let Some(old_cid_str) = should_delete_old {
            match CidLink::new(old_cid_str) {
                Ok(old_cid) => {
                    if let Ok(Some(storage_key)) = state
                        .repos
                        .infra
                        .get_blob_storage_key_by_cid(&old_cid)
                        .await
                    {
                        if let Err(e) = state.blob_store.delete(&storage_key).await {
                            error!("Failed to delete old logo blob from storage: {:?}", e);
                        }
                        if let Err(e) = state.repos.infra.delete_blob_by_cid(&old_cid).await {
                            error!("Failed to delete old logo blob record: {:?}", e);
                        }
                    }
                }
                Err(e) => {
                    warn!(
                        "Old logo CID in database is invalid, skipping cleanup: {:?}",
                        e
                    );
                }
            }
        }

        if logo_cid.is_empty() {
            state
                .repos
                .infra
                .delete_server_config("logo_cid")
                .await
                .log_db_err("deleting logo_cid")?;
        } else {
            state
                .repos
                .infra
                .upsert_server_config("logo_cid", logo_cid)
                .await
                .log_db_err("upserting logo_cid")?;
        }
    }

    Ok(Json(UpdateServerConfigOutput { success: true }))
}