use async_trait::async_trait;
use chrono::NaiveDateTime;
use domain::{
    errors::DomainError,
    models::{
        FieldMapping, ImportProfile,
        import::{DomainField, Transform},
    },
    ports::ImportProfileRepository,
    value_objects::{ImportProfileId, UserId},
};
use serde::{Deserialize, Serialize};
use sqlx::PgPool;

#[derive(Serialize, Deserialize)]
enum DomainFieldJson {
    Title,
    ReleaseYear,
    Director,
    Rating,
    WatchedAt,
    Comment,
    ExternalMetadataId,
}

#[derive(Serialize, Deserialize)]
enum TransformJson {
    RatingScale(f64),
    DateFormat(String),
    Identity,
}

#[derive(Serialize, Deserialize)]
struct FieldMappingJson {
    source_column: String,
    domain_field: DomainFieldJson,
    transform: TransformJson,
}

fn mapping_to_json(m: &FieldMapping) -> FieldMappingJson {
    FieldMappingJson {
        source_column: m.source_column.clone(),
        domain_field: match &m.domain_field {
            DomainField::Title => DomainFieldJson::Title,
            DomainField::ReleaseYear => DomainFieldJson::ReleaseYear,
            DomainField::Director => DomainFieldJson::Director,
            DomainField::Rating => DomainFieldJson::Rating,
            DomainField::WatchedAt => DomainFieldJson::WatchedAt,
            DomainField::Comment => DomainFieldJson::Comment,
            DomainField::ExternalMetadataId => DomainFieldJson::ExternalMetadataId,
        },
        transform: match &m.transform {
            Transform::RatingScale(f) => TransformJson::RatingScale(*f),
            Transform::DateFormat(s) => TransformJson::DateFormat(s.clone()),
            Transform::Identity => TransformJson::Identity,
        },
    }
}

fn mapping_from_json(j: FieldMappingJson) -> FieldMapping {
    FieldMapping {
        source_column: j.source_column,
        domain_field: match j.domain_field {
            DomainFieldJson::Title => DomainField::Title,
            DomainFieldJson::ReleaseYear => DomainField::ReleaseYear,
            DomainFieldJson::Director => DomainField::Director,
            DomainFieldJson::Rating => DomainField::Rating,
            DomainFieldJson::WatchedAt => DomainField::WatchedAt,
            DomainFieldJson::Comment => DomainField::Comment,
            DomainFieldJson::ExternalMetadataId => DomainField::ExternalMetadataId,
        },
        transform: match j.transform {
            TransformJson::RatingScale(f) => Transform::RatingScale(f),
            TransformJson::DateFormat(s) => Transform::DateFormat(s),
            TransformJson::Identity => Transform::Identity,
        },
    }
}

fn serialize_mappings(ms: &[FieldMapping]) -> Result<String, DomainError> {
    serde_json::to_string(&ms.iter().map(mapping_to_json).collect::<Vec<_>>())
        .map_err(|e| DomainError::InfrastructureError(e.to_string()))
}

fn deserialize_mappings(s: &str) -> Result<Vec<FieldMapping>, DomainError> {
    let js: Vec<FieldMappingJson> =
        serde_json::from_str(s).map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
    Ok(js.into_iter().map(mapping_from_json).collect())
}

pub struct PostgresImportProfileRepository {
    pool: PgPool,
}

impl PostgresImportProfileRepository {
    pub fn new(pool: PgPool) -> Self {
        Self { pool }
    }

    fn map_err(e: sqlx::Error) -> DomainError {
        tracing::error!("DB error: {:?}", e);
        DomainError::InfrastructureError("Database operation failed".into())
    }
}

#[async_trait]
impl ImportProfileRepository for PostgresImportProfileRepository {
    async fn save(&self, p: &ImportProfile) -> Result<(), DomainError> {
        let id = p.id.value().to_string();
        let user_id = p.user_id.value().to_string();
        let field_mappings = serialize_mappings(&p.field_mappings)?;
        sqlx::query(
            "INSERT INTO import_profiles (id, user_id, name, field_mappings, created_at)
             VALUES ($1, $2, $3, $4, $5)
             ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name, field_mappings = EXCLUDED.field_mappings",
        )
        .bind(&id).bind(&user_id).bind(&p.name).bind(&field_mappings).bind(p.created_at)
        .execute(&self.pool)
        .await
        .map(|_| ())
        .map_err(Self::map_err)
    }

    async fn list_for_user(&self, user_id: &UserId) -> Result<Vec<ImportProfile>, DomainError> {
        let uid = user_id.value().to_string();

        #[derive(sqlx::FromRow)]
        struct Row {
            id: String,
            user_id: String,
            name: String,
            field_mappings: String,
            created_at: NaiveDateTime,
        }

        let rows = sqlx::query_as::<_, Row>(
            "SELECT id, user_id, name, field_mappings, created_at FROM import_profiles WHERE user_id = $1 ORDER BY created_at DESC",
        )
        .bind(&uid)
        .fetch_all(&self.pool)
        .await
        .map_err(Self::map_err)?;

        rows.into_iter()
            .map(|r| {
                Ok(ImportProfile {
                    id: ImportProfileId::from_uuid(
                        r.id.parse::<uuid::Uuid>()
                            .map_err(|e| DomainError::InfrastructureError(e.to_string()))?,
                    ),
                    user_id: UserId::from_uuid(
                        r.user_id
                            .parse::<uuid::Uuid>()
                            .map_err(|e| DomainError::InfrastructureError(e.to_string()))?,
                    ),
                    name: r.name,
                    field_mappings: deserialize_mappings(&r.field_mappings)?,
                    created_at: r.created_at,
                })
            })
            .collect()
    }

    async fn get(
        &self,
        id: &ImportProfileId,
        user_id: &UserId,
    ) -> Result<Option<ImportProfile>, DomainError> {
        let id_str = id.value().to_string();
        let uid_str = user_id.value().to_string();

        #[derive(sqlx::FromRow)]
        struct Row {
            id: String,
            user_id: String,
            name: String,
            field_mappings: String,
            created_at: NaiveDateTime,
        }

        let row = sqlx::query_as::<_, Row>(
            "SELECT id, user_id, name, field_mappings, created_at FROM import_profiles WHERE id = $1 AND user_id = $2",
        )
        .bind(&id_str).bind(&uid_str)
        .fetch_optional(&self.pool)
        .await
        .map_err(Self::map_err)?;

        row.map(|r| {
            Ok(ImportProfile {
                id: ImportProfileId::from_uuid(
                    r.id.parse::<uuid::Uuid>()
                        .map_err(|e| DomainError::InfrastructureError(e.to_string()))?,
                ),
                user_id: UserId::from_uuid(
                    r.user_id
                        .parse::<uuid::Uuid>()
                        .map_err(|e| DomainError::InfrastructureError(e.to_string()))?,
                ),
                name: r.name,
                field_mappings: deserialize_mappings(&r.field_mappings)?,
                created_at: r.created_at,
            })
        })
        .transpose()
    }

    async fn delete(&self, id: &ImportProfileId) -> Result<(), DomainError> {
        let id_str = id.value().to_string();
        sqlx::query("DELETE FROM import_profiles WHERE id = $1")
            .bind(&id_str)
            .execute(&self.pool)
            .await
            .map(|_| ())
            .map_err(Self::map_err)
    }
}