//! AI runtime profile and its context-injection strategy.
//!
//! A profile is *declarative configuration* (see CONTEXT.md §9): adding an AI
//! means adding data, not code (Open/Closed). The [`crate::ports::AgentRuntime`]
//! port is parameterised by an [`AgentProfile`].

use serde::{Deserialize, Serialize};

use crate::error::DomainError;
use crate::ids::ProfileId;

/// Strategy for injecting an agent's `.md` context into the launched CLI.
///
/// Invariants:
/// - `ConventionFile.target` is a relative file name without `..` and not absolute,
/// - `Env.var` is a valid environment-variable identifier,
/// - `Flag.flag` is non-empty.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase", tag = "strategy")]
pub enum ContextInjection {
    /// Write/symlink the `.md` to a conventional file (e.g. `CLAUDE.md`).
    ConventionFile {
        /// Relative target file name.
        target: String,
    },
    /// Pass the context file path through a CLI flag.
    Flag {
        /// The flag template (e.g. `--context-file {path}` or `-f`).
        flag: String,
    },
    /// Pipe the Markdown content on stdin.
    Stdin,
    /// Pass the context via an environment variable.
    Env {
        /// Environment variable name.
        var: String,
    },
}

impl ContextInjection {
    /// Validated `ConventionFile` constructor.
    ///
    /// # Errors
    /// Returns [`DomainError::PathNotRelativeSafe`] if `target` is absolute or
    /// contains `..`.
    pub fn convention_file(target: impl Into<String>) -> Result<Self, DomainError> {
        let target = target.into();
        crate::validation::relative_safe(&target)?;
        Ok(Self::ConventionFile { target })
    }

    /// Validated `Flag` constructor.
    ///
    /// # Errors
    /// Returns [`DomainError::EmptyField`] if `flag` is empty.
    pub fn flag(flag: impl Into<String>) -> Result<Self, DomainError> {
        let flag = flag.into();
        crate::validation::non_empty(&flag, "contextInjection.flag")?;
        Ok(Self::Flag { flag })
    }

    /// `Stdin` constructor (no validation needed).
    #[must_use]
    pub const fn stdin() -> Self {
        Self::Stdin
    }

    /// Validated `Env` constructor.
    ///
    /// # Errors
    /// Returns [`DomainError::InvalidEnvVar`] if `var` is not a valid identifier.
    pub fn env(var: impl Into<String>) -> Result<Self, DomainError> {
        let var = var.into();
        crate::validation::valid_env_var(&var)?;
        Ok(Self::Env { var })
    }
}

/// Declarative runtime configuration for one AI CLI.
///
/// Invariants:
/// - `name` and `command` non-empty,
/// - `context_injection` is itself valid (guaranteed by its constructors).
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct AgentProfile {
    /// Stable identifier.
    pub id: ProfileId,
    /// Display name.
    pub name: String,
    /// Launch command (e.g. `claude`, `codex`, `gemini`, `aider`).
    pub command: String,
    /// Static arguments.
    pub args: Vec<String>,
    /// Context-injection strategy.
    pub context_injection: ContextInjection,
    /// Optional detection command (e.g. `claude --version`).
    pub detect: Option<String>,
    /// Working-directory template. Always `"{agentRunDir}"` (ARCHITECTURE §14.1):
    /// an agent's PTY cwd is its isolated `.ideai/run/<agent-id>/` directory,
    /// **never** the project root, so that N agents of the same profile never
    /// collide on a single conventional file (`CLAUDE.md`, …) at the root.
    pub cwd_template: String,
}

impl AgentProfile {
    /// Builds a validated profile.
    ///
    /// # Errors
    /// Returns [`DomainError::EmptyField`] if `name` or `command` is empty.
    #[allow(clippy::too_many_arguments)]
    pub fn new(
        id: ProfileId,
        name: impl Into<String>,
        command: impl Into<String>,
        args: Vec<String>,
        context_injection: ContextInjection,
        detect: Option<String>,
        cwd_template: impl Into<String>,
    ) -> Result<Self, DomainError> {
        let name = name.into();
        let command = command.into();
        let cwd_template = cwd_template.into();
        crate::validation::non_empty(&name, "profile.name")?;
        crate::validation::non_empty(&command, "profile.command")?;
        Ok(Self {
            id,
            name,
            command,
            args,
            context_injection,
            detect,
            cwd_template,
        })
    }
}