//! HTTP handlers for directive CRUD operations.

use axum::{
    extract::{Path, State},
    http::StatusCode,
    response::IntoResponse,
    Json,
};
use uuid::Uuid;

use std::collections::HashMap;

use crate::db::models::{
    ChainStep, ChainStepWithContract, ChainWithSteps, CreateDirectiveRequest, Directive,
    DirectiveChain, DirectiveListResponse, DirectiveWithChains, EvaluationListResponse,
    StepContractSummary, UpdateDirectiveRequest,
};
use crate::db::repository::{self, RepositoryError};
use crate::orchestration;
use crate::server::auth::Authenticated;
use crate::server::messages::ApiError;
use crate::server::state::SharedState;

/// List all directives for the authenticated user's owner.
#[utoipa::path(
    get,
    path = "/api/v1/directives",
    responses(
        (status = 200, description = "List of directives", body = DirectiveListResponse),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn list_directives(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match repository::list_directives_for_owner(pool, auth.owner_id).await {
        Ok(directives) => {
            let total = directives.len() as i64;
            Json(DirectiveListResponse { directives, total }).into_response()
        }
        Err(e) => {
            tracing::error!("Failed to list directives: {}", e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}

/// Get a directive by ID with its chains.
#[utoipa::path(
    get,
    path = "/api/v1/directives/{id}",
    params(
        ("id" = Uuid, Path, description = "Directive ID")
    ),
    responses(
        (status = 200, description = "Directive details with chains", body = DirectiveWithChains),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Directive not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn get_directive(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path(id): Path<Uuid>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    let directive = match repository::get_directive_for_owner(pool, id, auth.owner_id).await {
        Ok(Some(d)) => d,
        Ok(None) => {
            return (
                StatusCode::NOT_FOUND,
                Json(ApiError::new("NOT_FOUND", "Directive not found")),
            )
                .into_response();
        }
        Err(e) => {
            tracing::error!("Failed to get directive {}: {}", id, e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response();
        }
    };

    let chains = match repository::list_chains_for_directive(pool, id).await {
        Ok(c) => c,
        Err(e) => {
            tracing::warn!("Failed to get chains for directive {}: {}", id, e);
            Vec::new()
        }
    };

    // Build chains with steps
    let mut all_steps_by_chain = Vec::new();
    for chain in &chains {
        let steps = match repository::list_steps_for_chain(pool, chain.id).await {
            Ok(s) => s,
            Err(e) => {
                tracing::warn!("Failed to get steps for chain {}: {}", chain.id, e);
                Vec::new()
            }
        };
        all_steps_by_chain.push(steps);
    }

    // Collect all contract IDs (from steps + orchestrator)
    let mut contract_ids: Vec<Uuid> = all_steps_by_chain
        .iter()
        .flat_map(|steps| steps.iter().filter_map(|s| s.contract_id))
        .collect();
    if let Some(orch_id) = directive.orchestrator_contract_id {
        contract_ids.push(orch_id);
    }

    // Batch fetch contract summaries
    let mut summary_map: HashMap<Uuid, StepContractSummary> = if contract_ids.is_empty() {
        HashMap::new()
    } else {
        match repository::get_contract_summaries_batch(pool, &contract_ids).await {
            Ok(summaries) => summaries.into_iter().map(|s| (s.id, s)).collect(),
            Err(e) => {
                tracing::warn!("Failed to fetch contract summaries: {}", e);
                HashMap::new()
            }
        }
    };

    // Build enriched chains
    let chains_with_steps: Vec<ChainWithSteps> = chains
        .into_iter()
        .zip(all_steps_by_chain.into_iter())
        .map(|(chain, steps)| {
            let enriched_steps = steps
                .into_iter()
                .map(|step| {
                    let contract_summary =
                        step.contract_id.and_then(|id| summary_map.remove(&id));
                    ChainStepWithContract {
                        step,
                        contract_summary,
                    }
                })
                .collect();
            ChainWithSteps {
                chain,
                steps: enriched_steps,
            }
        })
        .collect();

    let orchestrator_contract_summary = directive
        .orchestrator_contract_id
        .and_then(|id| summary_map.remove(&id));

    Json(DirectiveWithChains {
        directive,
        orchestrator_contract_summary,
        chains: chains_with_steps,
    })
    .into_response()
}

/// Create a new directive.
#[utoipa::path(
    post,
    path = "/api/v1/directives",
    request_body = CreateDirectiveRequest,
    responses(
        (status = 201, description = "Directive created", body = Directive),
        (status = 400, description = "Invalid request", body = ApiError),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn create_directive(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Json(req): Json<CreateDirectiveRequest>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match repository::create_directive_for_owner(pool, auth.owner_id, req).await {
        Ok(directive) => (StatusCode::CREATED, Json(directive)).into_response(),
        Err(e) => {
            tracing::error!("Failed to create directive: {}", e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}

/// Update an existing directive.
#[utoipa::path(
    put,
    path = "/api/v1/directives/{id}",
    params(
        ("id" = Uuid, Path, description = "Directive ID")
    ),
    request_body = UpdateDirectiveRequest,
    responses(
        (status = 200, description = "Directive updated", body = Directive),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Directive not found", body = ApiError),
        (status = 409, description = "Version conflict", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn update_directive(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path(id): Path<Uuid>,
    Json(req): Json<UpdateDirectiveRequest>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match repository::update_directive_for_owner(pool, id, auth.owner_id, req).await {
        Ok(Some(directive)) => Json(directive).into_response(),
        Ok(None) => (
            StatusCode::NOT_FOUND,
            Json(ApiError::new("NOT_FOUND", "Directive not found")),
        )
            .into_response(),
        Err(RepositoryError::VersionConflict { expected, actual }) => (
            StatusCode::CONFLICT,
            Json(ApiError::new(
                "VERSION_CONFLICT",
                format!(
                    "Version conflict: expected {}, actual {}",
                    expected, actual
                ),
            )),
        )
            .into_response(),
        Err(RepositoryError::Database(e)) => {
            tracing::error!("Failed to update directive {}: {}", id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}

/// Delete a directive.
#[utoipa::path(
    delete,
    path = "/api/v1/directives/{id}",
    params(
        ("id" = Uuid, Path, description = "Directive ID")
    ),
    responses(
        (status = 204, description = "Directive deleted"),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Directive not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn delete_directive(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path(id): Path<Uuid>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match repository::delete_directive_for_owner(pool, id, auth.owner_id).await {
        Ok(true) => StatusCode::NO_CONTENT.into_response(),
        Ok(false) => (
            StatusCode::NOT_FOUND,
            Json(ApiError::new("NOT_FOUND", "Directive not found")),
        )
            .into_response(),
        Err(e) => {
            tracing::error!("Failed to delete directive {}: {}", id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}

/// List chains for a directive.
#[utoipa::path(
    get,
    path = "/api/v1/directives/{id}/chains",
    params(
        ("id" = Uuid, Path, description = "Directive ID")
    ),
    responses(
        (status = 200, description = "List of chains", body = Vec<DirectiveChain>),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Directive not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn list_chains(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path(id): Path<Uuid>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    // Verify directive exists and belongs to owner
    match repository::get_directive_for_owner(pool, id, auth.owner_id).await {
        Ok(Some(_)) => {}
        Ok(None) => {
            return (
                StatusCode::NOT_FOUND,
                Json(ApiError::new("NOT_FOUND", "Directive not found")),
            )
                .into_response();
        }
        Err(e) => {
            tracing::error!("Failed to get directive {}: {}", id, e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response();
        }
    }

    match repository::list_chains_for_directive(pool, id).await {
        Ok(chains) => Json(chains).into_response(),
        Err(e) => {
            tracing::error!("Failed to list chains for directive {}: {}", id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}

/// Get a chain with its steps.
#[utoipa::path(
    get,
    path = "/api/v1/directives/{id}/chains/{chain_id}",
    params(
        ("id" = Uuid, Path, description = "Directive ID"),
        ("chain_id" = Uuid, Path, description = "Chain ID")
    ),
    responses(
        (status = 200, description = "Chain with steps", body = ChainWithSteps),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Chain not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn get_chain(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path((id, chain_id)): Path<(Uuid, Uuid)>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    // Verify directive exists and belongs to owner
    match repository::get_directive_for_owner(pool, id, auth.owner_id).await {
        Ok(Some(_)) => {}
        Ok(None) => {
            return (
                StatusCode::NOT_FOUND,
                Json(ApiError::new("NOT_FOUND", "Directive not found")),
            )
                .into_response();
        }
        Err(e) => {
            tracing::error!("Failed to get directive {}: {}", id, e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response();
        }
    }

    // Get the chain and verify it belongs to this directive
    let chains = match repository::list_chains_for_directive(pool, id).await {
        Ok(c) => c,
        Err(e) => {
            tracing::error!("Failed to list chains: {}", e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response();
        }
    };

    let chain = match chains.into_iter().find(|c| c.id == chain_id) {
        Some(c) => c,
        None => {
            return (
                StatusCode::NOT_FOUND,
                Json(ApiError::new("NOT_FOUND", "Chain not found")),
            )
                .into_response();
        }
    };

    let steps = match repository::list_steps_for_chain(pool, chain_id).await {
        Ok(s) => s,
        Err(e) => {
            tracing::warn!("Failed to get steps for chain {}: {}", chain_id, e);
            Vec::new()
        }
    };

    // Collect contract IDs from steps
    let contract_ids: Vec<Uuid> = steps.iter().filter_map(|s| s.contract_id).collect();

    let mut summary_map: HashMap<Uuid, StepContractSummary> = if contract_ids.is_empty() {
        HashMap::new()
    } else {
        match repository::get_contract_summaries_batch(pool, &contract_ids).await {
            Ok(summaries) => summaries.into_iter().map(|s| (s.id, s)).collect(),
            Err(e) => {
                tracing::warn!("Failed to fetch contract summaries: {}", e);
                HashMap::new()
            }
        }
    };

    let enriched_steps = steps
        .into_iter()
        .map(|step| {
            let contract_summary = step.contract_id.and_then(|id| summary_map.remove(&id));
            ChainStepWithContract {
                step,
                contract_summary,
            }
        })
        .collect();

    Json(ChainWithSteps {
        chain,
        steps: enriched_steps,
    })
    .into_response()
}

/// Start a directive: create a planning contract and begin orchestration.
#[utoipa::path(
    post,
    path = "/api/v1/directives/{id}/start",
    params(
        ("id" = Uuid, Path, description = "Directive ID")
    ),
    responses(
        (status = 200, description = "Directive started", body = Directive),
        (status = 400, description = "Directive not in draft status", body = ApiError),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Directive not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn start_directive(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path(id): Path<Uuid>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match orchestration::directive::init_directive(pool, &state, auth.owner_id, id).await {
        Ok(directive) => Json(directive).into_response(),
        Err(e) if e.contains("not found") => (
            StatusCode::NOT_FOUND,
            Json(ApiError::new("NOT_FOUND", e)),
        )
            .into_response(),
        Err(e) if e.contains("must be in 'draft'") => (
            StatusCode::BAD_REQUEST,
            Json(ApiError::new("INVALID_STATUS", e)),
        )
            .into_response(),
        Err(e) => {
            tracing::error!("Failed to start directive {}: {}", id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("START_FAILED", e)),
            )
                .into_response()
        }
    }
}

/// Trigger a manual evaluation for a step.
#[utoipa::path(
    post,
    path = "/api/v1/directives/{id}/steps/{step_id}/evaluate",
    params(
        ("id" = Uuid, Path, description = "Directive ID"),
        ("step_id" = Uuid, Path, description = "Step ID")
    ),
    responses(
        (status = 200, description = "Evaluation triggered", body = ChainStep),
        (status = 400, description = "Step cannot be evaluated", body = ApiError),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn evaluate_step(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path((id, step_id)): Path<(Uuid, Uuid)>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    match orchestration::directive::trigger_manual_evaluation(pool, &state, auth.owner_id, id, step_id).await {
        Ok(step) => Json(step).into_response(),
        Err(e) if e.contains("not found") || e.contains("Not found") => (
            StatusCode::NOT_FOUND,
            Json(ApiError::new("NOT_FOUND", e)),
        )
            .into_response(),
        Err(e) if e.contains("hasn't been executed") || e.contains("no active chain") => (
            StatusCode::BAD_REQUEST,
            Json(ApiError::new("INVALID_STATE", e)),
        )
            .into_response(),
        Err(e) => {
            tracing::error!("Failed to trigger evaluation for step {}: {}", step_id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("EVALUATION_FAILED", e)),
            )
                .into_response()
        }
    }
}

/// List evaluations for a step.
#[utoipa::path(
    get,
    path = "/api/v1/directives/{id}/steps/{step_id}/evaluations",
    params(
        ("id" = Uuid, Path, description = "Directive ID"),
        ("step_id" = Uuid, Path, description = "Step ID")
    ),
    responses(
        (status = 200, description = "List of evaluations", body = EvaluationListResponse),
        (status = 401, description = "Unauthorized", body = ApiError),
        (status = 404, description = "Not found", body = ApiError),
        (status = 503, description = "Database not configured", body = ApiError),
        (status = 500, description = "Internal server error", body = ApiError),
    ),
    security(
        ("bearer_auth" = []),
        ("api_key" = [])
    ),
    tag = "Directives"
)]
pub async fn list_evaluations(
    State(state): State<SharedState>,
    Authenticated(auth): Authenticated,
    Path((id, step_id)): Path<(Uuid, Uuid)>,
) -> impl IntoResponse {
    let Some(ref pool) = state.db_pool else {
        return (
            StatusCode::SERVICE_UNAVAILABLE,
            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
        )
            .into_response();
    };

    // Verify directive exists and belongs to owner
    match repository::get_directive_for_owner(pool, id, auth.owner_id).await {
        Ok(Some(_)) => {}
        Ok(None) => {
            return (
                StatusCode::NOT_FOUND,
                Json(ApiError::new("NOT_FOUND", "Directive not found")),
            )
                .into_response();
        }
        Err(e) => {
            tracing::error!("Failed to get directive {}: {}", id, e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response();
        }
    }

    match repository::list_evaluations_for_step(pool, step_id).await {
        Ok(evaluations) => {
            let total = evaluations.len() as i64;
            Json(EvaluationListResponse { evaluations, total }).into_response()
        }
        Err(e) => {
            tracing::error!("Failed to list evaluations for step {}: {}", step_id, e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(ApiError::new("DB_ERROR", e.to_string())),
            )
                .into_response()
        }
    }
}