//! Central approval policy-stage execution and reviewer routing.

use crate::command_canonicalization::canonicalize_command_for_approval;
use crate::guardian::GuardianReviewContext;
use crate::guardian::guardian_timeout_message;
use crate::guardian::new_guardian_review_id;
use crate::guardian::review_approval_request;
use crate::guardian::routes_approval_to_guardian_with_reviewer;
use crate::hook_runtime::run_permission_request_hooks;
use crate::sandboxing::SandboxPermissions;
use crate::session::session::Session;
use crate::session::turn_context::TurnContext;
use crate::tools::flat_tool_name;
use crate::tools::hook_names::HookToolName;
use crate::tools::runtimes::apply_patch::ApplyPatchApprovalKey;
use crate::tools::runtimes::shell::ApprovalKey;
use crate::tools::runtimes::unified_exec::UnifiedExecApprovalKey;
use crate::tools::sandboxing::ApprovalRequestReasons;
use crate::tools::sandboxing::PermissionRequestPayload;
use crate::tools::sandboxing::ToolError;
use crate::tools::sandboxing::with_cached_approval;
use codex_hooks::PermissionRequestDecision;
use codex_otel::ToolDecisionSource;
use codex_protocol::approvals::ExecPolicyAmendment;
#[cfg(unix)]
use codex_protocol::approvals::GuardianCommandSource;
use codex_protocol::approvals::NetworkApprovalContext;
use codex_protocol::error::CodexErr;
use codex_protocol::models::AdditionalPermissionProfile;
use codex_protocol::protocol::FileChange;
use codex_protocol::protocol::NetworkPolicyRuleAction;
use codex_protocol::protocol::ReviewDecision;
use codex_tools::ToolName;
use codex_utils_absolute_path::AbsolutePathBuf;
use codex_utils_path_uri::PathUri;
use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::Arc;
use tracing::error;

#[derive(Clone)]
pub(crate) struct ApprovalContext {
    pub(crate) review_context: GuardianReviewContext,
    pub(crate) call_id: String,
    pub(crate) tool_name: ToolName,
    pub(crate) strict_auto_review: bool,
    pub(crate) approval_reason: Option<String>,
    pub(crate) retry_reason: Option<String>,
    pub(crate) network_approval_context: Option<NetworkApprovalContext>,
}

#[derive(Clone, Debug, PartialEq)]
pub(crate) enum ApprovalAction {
    Shell {
        id: String,
        environment_id: String,
        command: Vec<String>,
        hook_command: String,
        cwd: PathUri,
        sandbox_permissions: SandboxPermissions,
        additional_permissions: Option<AdditionalPermissionProfile>,
        justification: Option<String>,
        proposed_execpolicy_amendment: Option<ExecPolicyAmendment>,
    },
    ExecCommand {
        id: String,
        environment_id: String,
        command: Vec<String>,
        hook_command: String,
        cwd: PathUri,
        sandbox_permissions: SandboxPermissions,
        additional_permissions: Option<AdditionalPermissionProfile>,
        justification: Option<String>,
        tty: bool,
        proposed_execpolicy_amendment: Option<ExecPolicyAmendment>,
    },
    #[cfg(unix)]
    Execve {
        id: String,
        approval_id: String,
        environment_id: String,
        source: GuardianCommandSource,
        program: AbsolutePathBuf,
        argv: Vec<String>,
        command: Vec<String>,
        cwd: AbsolutePathBuf,
        additional_permissions: Option<AdditionalPermissionProfile>,
    },
    ApplyPatch {
        id: String,
        environment_id: String,
        cwd: PathUri,
        files: Vec<PathUri>,
        patch: String,
        changes: Arc<HashMap<PathBuf, FileChange>>,
        permissions_preapproved: bool,
    },
}

#[derive(Clone, Debug, Eq, Hash, PartialEq, serde::Serialize)]
#[serde(untagged)]
pub(crate) enum ApprovalCacheKey {
    Shell(ApprovalKey),
    ExecCommand(UnifiedExecApprovalKey),
    ApplyPatch(ApplyPatchApprovalKey),
}

impl ApprovalAction {
    pub(crate) fn permission_request_payload(&self) -> PermissionRequestPayload {
        match self {
            Self::Shell {
                hook_command,
                justification,
                ..
            }
            | Self::ExecCommand {
                hook_command,
                justification,
                ..
            } => PermissionRequestPayload::bash(hook_command.clone(), justification.clone()),
            #[cfg(unix)]
            Self::Execve { command, .. } => PermissionRequestPayload::bash(
                codex_shell_command::parse_command::shlex_join(command),
                /*description*/ None,
            ),
            Self::ApplyPatch { patch, .. } => PermissionRequestPayload {
                tool_name: HookToolName::apply_patch(),
                tool_input: serde_json::json!({ "command": patch }),
            },
        }
    }

    pub(crate) fn cache_keys(&self) -> Vec<ApprovalCacheKey> {
        match self {
            Self::Shell {
                environment_id,
                command,
                cwd,
                sandbox_permissions,
                additional_permissions,
                ..
            } => vec![ApprovalCacheKey::Shell(ApprovalKey {
                environment_id: environment_id.clone(),
                command: canonicalize_command_for_approval(command),
                cwd: cwd.clone(),
                sandbox_permissions: *sandbox_permissions,
                additional_permissions: additional_permissions.clone(),
            })],
            Self::ExecCommand {
                environment_id,
                command,
                cwd,
                tty,
                sandbox_permissions,
                additional_permissions,
                ..
            } => vec![ApprovalCacheKey::ExecCommand(UnifiedExecApprovalKey {
                environment_id: environment_id.clone(),
                command: canonicalize_command_for_approval(command),
                cwd: cwd.clone(),
                tty: *tty,
                sandbox_permissions: *sandbox_permissions,
                additional_permissions: additional_permissions.clone(),
            })],
            #[cfg(unix)]
            Self::Execve { .. } => Vec::new(),
            Self::ApplyPatch {
                environment_id,
                files,
                ..
            } => files
                .iter()
                .cloned()
                .map(|path| {
                    ApprovalCacheKey::ApplyPatch(ApplyPatchApprovalKey {
                        environment_id: environment_id.clone(),
                        path,
                    })
                })
                .collect(),
        }
    }

    fn into_guardian_request(self) -> std::io::Result<crate::guardian::GuardianApprovalRequest> {
        Ok(match self {
            Self::Shell {
                id,
                environment_id,
                command,
                cwd,
                sandbox_permissions,
                additional_permissions,
                justification,
                ..
            } => crate::guardian::GuardianApprovalRequest::Shell {
                id,
                command,
                cwd: guardian_cwd(&environment_id, cwd)?,
                sandbox_permissions,
                additional_permissions,
                justification,
            },
            Self::ExecCommand {
                id,
                environment_id,
                command,
                cwd,
                sandbox_permissions,
                additional_permissions,
                justification,
                tty,
                ..
            } => crate::guardian::GuardianApprovalRequest::ExecCommand {
                id,
                command,
                cwd: guardian_cwd(&environment_id, cwd)?,
                sandbox_permissions,
                additional_permissions,
                justification,
                tty,
            },
            #[cfg(unix)]
            Self::Execve {
                id,
                source,
                program,
                argv,
                cwd,
                additional_permissions,
                ..
            } => crate::guardian::GuardianApprovalRequest::Execve {
                id,
                source,
                program: program.to_string_lossy().into_owned(),
                argv,
                cwd,
                additional_permissions,
            },
            Self::ApplyPatch {
                id,
                environment_id,
                cwd,
                files,
                patch,
                ..
            } => crate::guardian::GuardianApprovalRequest::ApplyPatch {
                id,
                cwd: guardian_cwd(&environment_id, cwd)?,
                files: files
                    .into_iter()
                    .map(|path| path.to_abs_path())
                    .collect::<std::io::Result<Vec<_>>>()?,
                patch,
            },
        })
    }
}

fn guardian_cwd(environment_id: &str, cwd: PathUri) -> std::io::Result<AbsolutePathBuf> {
    match cwd.to_abs_path() {
        Ok(cwd) => Ok(cwd),
        Err(err) if environment_id != codex_exec_server::LOCAL_ENVIRONMENT_ID => Err(err),
        Err(_) => {
            let cwd_display = cwd.to_string();
            let path = cwd.to_url().to_file_path().map_err(|()| {
                std::io::Error::new(
                    std::io::ErrorKind::InvalidInput,
                    format!("local cwd URI `{cwd_display}` is not a host-native path"),
                )
            })?;
            AbsolutePathBuf::from_absolute_path_checked(path).map_err(|err| {
                std::io::Error::new(
                    std::io::ErrorKind::InvalidInput,
                    format!("local cwd URI `{cwd_display}` is not absolute: {err}"),
                )
            })
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum ApprovalReviewer {
    Guardian,
    User,
}

impl ApprovalReviewer {
    fn for_turn(turn: &TurnContext) -> Self {
        if routes_approval_to_guardian_with_reviewer(turn, turn.config.approvals_reviewer) {
            Self::Guardian
        } else {
            Self::User
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum ApprovalResolutionSource {
    Hook,
    Guardian,
    User,
}

#[derive(Clone, Debug, PartialEq, Eq)]
struct ApprovalResolution {
    decision: ReviewDecision,
    source: ApprovalResolutionSource,
}

impl ApprovalResolution {
    fn into_tool_result(self) -> Result<ReviewDecision, ToolError> {
        let source = self.source;
        match self.decision {
            ReviewDecision::ApprovedMcpPolicyAmendment => {
                error!("Tool approval received ApprovedMcpPolicyAmendment");
                Err(ToolError::Rejected(
                    "Error while requesting approval".to_string(),
                ))
            }
            ReviewDecision::NetworkPolicyAmendment {
                network_policy_amendment,
            } if network_policy_amendment.action == NetworkPolicyRuleAction::Deny => {
                let rejection = match source {
                    ApprovalResolutionSource::Hook => "rejected by configuration",
                    ApprovalResolutionSource::Guardian => {
                        "automatic approval review denied the action"
                    }
                    ApprovalResolutionSource::User => "rejected by user",
                };
                Err(ToolError::Rejected(rejection.to_string()))
            }
            ReviewDecision::Denied { rejection } => Err(ToolError::Rejected(rejection)),
            ReviewDecision::TimedOut => Err(ToolError::Rejected(guardian_timeout_message())),
            ReviewDecision::Abort => Err(ToolError::Codex(CodexErr::TurnAborted)),
            decision => Ok(decision),
        }
    }
}

impl Session {
    pub(crate) async fn request_approval(
        self: &Arc<Self>,
        action: ApprovalAction,
        ctx: ApprovalContext,
    ) -> Result<ReviewDecision, ToolError> {
        let permission_request_run_id = match &action {
            #[cfg(unix)]
            ApprovalAction::Execve { approval_id, .. } => approval_id.clone(),
            _ if ctx.retry_reason.is_some() => format!("{}:retry", ctx.call_id),
            _ => ctx.call_id.clone(),
        };

        // Approval precedence is:
        // 1. Hooks
        // 2. If StrictAutoReview || Guardian enabled, then Guardian. Else, user.
        let resolution = match run_permission_request_hooks(
            self,
            ctx.review_context.turn(),
            &permission_request_run_id,
            action.permission_request_payload(),
        )
        .await
        {
            Some(PermissionRequestDecision::Allow) => ApprovalResolution {
                decision: ReviewDecision::Approved,
                source: ApprovalResolutionSource::Hook,
            },
            Some(PermissionRequestDecision::Deny { message }) => ApprovalResolution {
                decision: ReviewDecision::denied(message),
                source: ApprovalResolutionSource::Hook,
            },
            None => self.request_reviewer_approval(action, &ctx).await,
        };
        record_resolution(&ctx, &resolution);
        resolution.into_tool_result()
    }

    async fn request_reviewer_approval(
        self: &Arc<Self>,
        action: ApprovalAction,
        ctx: &ApprovalContext,
    ) -> ApprovalResolution {
        let reviewer = if ctx.strict_auto_review {
            ApprovalReviewer::Guardian
        } else {
            ApprovalReviewer::for_turn(ctx.review_context.turn())
        };

        let decision = match reviewer {
            ApprovalReviewer::Guardian => self.request_guardian_approval(action, ctx).await,
            ApprovalReviewer::User => self.request_user_approval(&action, ctx).await,
        };
        let source = match reviewer {
            ApprovalReviewer::Guardian => ApprovalResolutionSource::Guardian,
            ApprovalReviewer::User => ApprovalResolutionSource::User,
        };
        ApprovalResolution { decision, source }
    }

    async fn request_guardian_approval(
        self: &Arc<Self>,
        action: ApprovalAction,
        ctx: &ApprovalContext,
    ) -> ReviewDecision {
        let review_id = new_guardian_review_id();
        let action = match action.into_guardian_request() {
            Ok(action) => action,
            Err(err) => {
                tracing::error!(%err, "failed to build automatic approval action");
                return ReviewDecision::denied(
                    "automatic approval review could not prepare the action",
                );
            }
        };

        review_approval_request(
            self,
            ctx.review_context.clone(),
            review_id,
            action,
            ApprovalRequestReasons {
                approval: ctx.approval_reason.clone(),
                retry: ctx.retry_reason.clone(),
            },
        )
        .await
    }

    async fn request_user_approval(
        &self,
        action: &ApprovalAction,
        ctx: &ApprovalContext,
    ) -> ReviewDecision {
        match action {
            ApprovalAction::Shell {
                environment_id,
                command,
                cwd,
                additional_permissions,
                justification,
                proposed_execpolicy_amendment,
                ..
            }
            | ApprovalAction::ExecCommand {
                environment_id,
                command,
                cwd,
                additional_permissions,
                justification,
                proposed_execpolicy_amendment,
                ..
            } => {
                let cwd = match guardian_cwd(environment_id, cwd.clone()) {
                    Ok(cwd) => cwd,
                    Err(err) => {
                        tracing::error!(%err, "failed to resolve approval command cwd");
                        return ReviewDecision::denied(format!(
                            "failed to resolve approval command cwd: {err}"
                        ));
                    }
                };
                let tool_name = match action {
                    ApprovalAction::Shell { .. } => "shell",
                    ApprovalAction::ExecCommand { .. } => "unified_exec",
                    #[cfg(unix)]
                    ApprovalAction::Execve { .. } => unreachable!("matched command approval"),
                    ApprovalAction::ApplyPatch { .. } => unreachable!("matched command approval"),
                };
                let reason = ctx
                    .retry_reason
                    .clone()
                    .or_else(|| ctx.approval_reason.clone())
                    .or_else(|| justification.clone());
                with_cached_approval(&self.services, tool_name, action.cache_keys(), || async {
                    self.request_command_approval(
                        ctx.review_context.turn(),
                        ctx.call_id.clone(),
                        /*approval_id*/ None,
                        Some(environment_id.clone()),
                        command.clone(),
                        cwd,
                        reason,
                        ctx.network_approval_context.clone(),
                        proposed_execpolicy_amendment.clone(),
                        additional_permissions.clone(),
                        /*available_decisions*/ None,
                        /*plugin_attribution_override*/ None,
                    )
                    .await
                })
                .await
            }
            #[cfg(unix)]
            ApprovalAction::Execve {
                approval_id,
                environment_id,
                command,
                cwd,
                additional_permissions,
                ..
            } => {
                self.request_command_approval(
                    ctx.review_context.turn(),
                    ctx.call_id.clone(),
                    Some(approval_id.clone()),
                    Some(environment_id.clone()),
                    command.clone(),
                    cwd.clone(),
                    /*reason*/ None,
                    /*network_approval_context*/ None,
                    /*proposed_execpolicy_amendment*/ None,
                    additional_permissions.clone(),
                    Some(vec![ReviewDecision::Approved, ReviewDecision::Abort]),
                    /*plugin_attribution_override*/ None,
                )
                .await
            }
            ApprovalAction::ApplyPatch {
                changes,
                permissions_preapproved,
                ..
            } => {
                let reason = ctx
                    .retry_reason
                    .clone()
                    .or_else(|| ctx.approval_reason.clone());
                if *permissions_preapproved && reason.is_none() {
                    return ReviewDecision::Approved;
                }
                if reason.is_some() {
                    return self
                        .request_patch_approval(
                            ctx.review_context.turn(),
                            ctx.call_id.clone(),
                            changes.as_ref().clone(),
                            reason,
                            /*grant_root*/ None,
                        )
                        .await;
                }
                with_cached_approval(
                    &self.services,
                    "apply_patch",
                    action.cache_keys(),
                    || async {
                        self.request_patch_approval(
                            ctx.review_context.turn(),
                            ctx.call_id.clone(),
                            changes.as_ref().clone(),
                            /*reason*/ None,
                            /*grant_root*/ None,
                        )
                        .await
                    },
                )
                .await
            }
        }
    }
}

fn record_resolution(ctx: &ApprovalContext, resolution: &ApprovalResolution) {
    let source = match resolution.source {
        ApprovalResolutionSource::Hook => ToolDecisionSource::Config,
        ApprovalResolutionSource::Guardian => ToolDecisionSource::AutomatedReviewer,
        ApprovalResolutionSource::User => ToolDecisionSource::User,
    };
    let tool_name = flat_tool_name(&ctx.tool_name);
    ctx.review_context.turn().session_telemetry.tool_decision(
        tool_name.as_ref(),
        &ctx.call_id,
        &resolution.decision,
        source,
    );
}

#[cfg(all(test, unix))]
#[path = "approvals_tests.rs"]
mod tests;