//! An alternative as the visitor meets it, in text.
//!
//! Portal renders a card: the heading, the description, a button, one
//! or two encouragements, and for each section an icon, a title, a
//! line of guidance and the fields with their labels and placeholders.
//! A visitor is oriented by all of it, not the heading alone. The
//! answering visitor and `rate` both read this rendering, so the
//! scored page is the served page; the gutted twin keeps the card's
//! shape and none of its words.

use serde_json::Value;

pub fn s(v: &Value) -> &str {
    v.as_str().unwrap_or_default()
}

/// One option on a page. `full` is the card as rendered; otherwise the
/// heading alone, which is what a visitor who reads nothing else sees.
pub fn alternative(alt: &Value, full: bool) -> String {
    let mut out = format!("- {}", s(&alt["name"]));
    if !full {
        out.push('\n');
        return out;
    }
    let d = s(&alt["description"]).trim();
    if !d.is_empty() {
        out.push_str(&format!(": {d}"));
    }
    out.push('\n');
    if let Some(button) = alt["consequence"].as_array().and_then(|c| c.first()).and_then(Value::as_str) {
        out.push_str(&format!("  Button: {button}\n"));
    }
    for e in alt["encouragements"].as_array().into_iter().flatten().filter_map(Value::as_str) {
        out.push_str(&format!("  {e}\n"));
    }
    for f in alt["features"].as_array().into_iter().flatten() {
        let (name, desc, icon) = (s(&f["name"]).trim(), s(&f["description"]).trim(), s(&f["icon"]).trim());
        let mut line = String::from("  ");
        if !icon.is_empty() {
            line.push_str(&format!("[icon {}] ", icon.rsplit(':').next().unwrap_or(icon)));
        }
        if !name.is_empty() {
            line.push_str(name);
        }
        if !desc.is_empty() {
            line.push_str(&format!("{}{desc}", if name.is_empty() { "" } else { ": " }));
        }
        if !line.trim().is_empty() {
            out.push_str(line.trim_end());
            out.push('\n');
        }
        let fields: Vec<String> = f["requirements"]
            .as_array()
            .into_iter()
            .flatten()
            .map(|r| {
                let label = r["label"].as_str().unwrap_or_else(|| s(&r["name"]));
                let hint = s(&r["placeholder"]).trim();
                let opt = if r["optional"] == true { " (optional)" } else { "" };
                if hint.is_empty() { format!("{label}{opt}") } else { format!("{label}{opt} e.g. {hint}") }
            })
            .collect();
        if !fields.is_empty() {
            out.push_str(&format!("  Asks for: {}\n", fields.join("; ")));
        }
    }
    out
}

/// The page around its options: what it asks and says of itself.
pub fn page_head(page: &Value) -> String {
    let mut out = format!("{}\n", s(&page["name"]));
    let d = s(&page["description"]).trim();
    if !d.is_empty() {
        out.push_str(&format!("{d}\n"));
    }
    out
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    #[test]
    fn a_card_reads_as_the_visitor_sees_it_and_a_heading_alone_is_a_heading_alone() {
        let alt = json!({
            "name": "Get a price", "description": "For owners.",
            "consequence": ["Send it"], "encouragements": ["We answer within two days."],
            "features": [{"name": "Your brief", "icon": "lucide:file-text", "description": "A few lines are enough.",
                          "requirements": [{"name": "email", "label": "Email", "placeholder": "you@example.no"},
                                           {"name": "address", "label": "Address", "optional": true}]}]
        });
        let full = alternative(&alt, true);
        assert!(full.starts_with("- Get a price: For owners.\n"));
        assert!(full.contains("Button: Send it") && full.contains("We answer within two days."));
        assert!(full.contains("[icon file-text] Your brief: A few lines are enough."));
        assert!(full.contains("Asks for: Email e.g. you@example.no; Address (optional)"));
        assert_eq!(alternative(&alt, false), "- Get a price\n");
    }
}