use anyhow::Result;
use sqlx::PgPool;
use uuid::Uuid;

use crate::models::ExportFormat;
use crate::service::add::{AddParams, run as add_run};
use crate::service::export::{build_meta_entries, build_secret_entries};

#[derive(Debug, serde::Serialize)]
pub struct ImportSummary {
    pub total: usize,
    pub inserted: usize,
    pub skipped: usize,
    pub failed: usize,
    pub dry_run: bool,
}

pub struct ImportParams<'a> {
    pub file: &'a str,
    pub force: bool,
    pub dry_run: bool,
    pub user_id: Option<Uuid>,
}

pub async fn run(
    pool: &PgPool,
    params: ImportParams<'_>,
    master_key: &[u8; 32],
) -> Result<ImportSummary> {
    let format = ExportFormat::from_extension(params.file)?;
    let content = std::fs::read_to_string(params.file)
        .map_err(|e| anyhow::anyhow!("Cannot read file '{}': {}", params.file, e))?;
    let data = format.deserialize(&content)?;

    if data.version != 1 {
        anyhow::bail!(
            "Unsupported export version {}. Only version 1 is supported.",
            data.version
        );
    }

    let total = data.entries.len();
    let mut inserted = 0usize;
    let mut skipped = 0usize;
    let mut failed = 0usize;

    for entry in &data.entries {
        let exists: bool = sqlx::query_scalar(
            "SELECT EXISTS(SELECT 1 FROM entries \
             WHERE folder = $1 AND name = $2 AND user_id IS NOT DISTINCT FROM $3)",
        )
        .bind(&entry.folder)
        .bind(&entry.name)
        .bind(params.user_id)
        .fetch_one(pool)
        .await
        .unwrap_or(false);

        if exists && !params.force {
            return Err(anyhow::anyhow!(
                "Import aborted: conflict on '{}'",
                entry.name
            ));
        }

        if params.dry_run {
            if exists {
                skipped += 1;
            } else {
                inserted += 1;
            }
            continue;
        }

        let secret_entries = build_secret_entries(entry.secrets.as_ref());
        let meta_entries = build_meta_entries(&entry.metadata);

        match add_run(
            pool,
            AddParams {
                name: &entry.name,
                folder: &entry.folder,
                entry_type: &entry.entry_type,
                notes: &entry.notes,
                tags: &entry.tags,
                meta_entries: &meta_entries,
                secret_entries: &secret_entries,
                link_secret_names: &[],
                user_id: params.user_id,
            },
            master_key,
        )
        .await
        {
            Ok(_) => {
                inserted += 1;
            }
            Err(e) => {
                tracing::error!(
                    name = entry.name,
                    error = %e,
                    "failed to import entry"
                );
                failed += 1;
            }
        }
    }

    if failed > 0 {
        return Err(anyhow::anyhow!("{} record(s) failed to import", failed));
    }

    Ok(ImportSummary {
        total,
        inserted,
        skipped,
        failed,
        dry_run: params.dry_run,
    })
}