//! Machine-local user preferences and project-owned presentation settings.

use serde::{Deserialize, Serialize};

/// Preferred interface when a new human-facing agent terminal is opened.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum DefaultAgentTerminalInterface {
    /// Provider's native interactive terminal UI.
    NativeTui,
    /// IdeA's structured/custom CLI chat surface.
    IdeaCli,
}

/// Global, machine-local IdeA preferences.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct IdeaUserSettings {
    /// Default for newly launched human-facing agent terminals.
    #[serde(default)]
    pub default_agent_terminal_interface: Option<DefaultAgentTerminalInterface>,
}

/// Strict project theme colour (`#RRGGBB`).
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(try_from = "String", into = "String")]
pub struct ThemeColor(String);

impl ThemeColor {
    /// Validates and builds a project theme colour.
    pub fn new(value: impl Into<String>) -> Result<Self, String> {
        let value = value.into();
        let valid = value.len() == 7
            && value.starts_with('#')
            && value.as_bytes()[1..].iter().all(u8::is_ascii_hexdigit);
        valid
            .then_some(Self(value))
            .ok_or_else(|| "themeColor must match #RRGGBB".to_owned())
    }

    /// Returns the validated wire representation.
    #[must_use]
    pub fn as_str(&self) -> &str {
        &self.0
    }
}

impl TryFrom<String> for ThemeColor {
    type Error = String;

    fn try_from(value: String) -> Result<Self, Self::Error> {
        Self::new(value)
    }
}

impl From<ThemeColor> for String {
    fn from(value: ThemeColor) -> Self {
        value.0
    }
}

/// Settings owned by one project and stored below its `.ideai` directory.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct ProjectSettings {
    /// Optional visual theme colour; absence keeps the product fallback.
    #[serde(default)]
    pub theme_color: Option<ThemeColor>,
}