use dioxus::prelude::*;

/// Month boundaries as week ranges (approximate ISO weeks).
/// Jan=1-4, Feb=5-8, Mar=9-13, Apr=14-17, May=18-22, Jun=23-26,
/// Jul=27-30, Aug=31-35, Sep=36-39, Oct=40-44, Nov=45-48, Dec=49-52
const MONTH_WEEK_RANGES: [(u8, u8); 12] = [
    (1, 4), (5, 8), (9, 13), (14, 17), (18, 22), (23, 26),
    (27, 30), (31, 35), (36, 39), (40, 44), (45, 48), (49, 52),
];

const MONTH_LABELS: [&str; 12] = [
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
];

/// Expand month data (1-12) into week numbers (1-52) for fallback.
fn months_to_weeks(months: &Option<Vec<i32>>) -> Option<Vec<i32>> {
    let m = months.as_ref()?;
    if m.is_empty() { return None; }
    let mut weeks = Vec::new();
    for &month in m {
        if month >= 1 && month <= 12 {
            let (start, end) = MONTH_WEEK_RANGES[(month - 1) as usize];
            for w in start..=end {
                weeks.push(w as i32);
            }
        }
    }
    weeks.sort();
    weeks.dedup();
    Some(weeks)
}

/// Resolve: prefer week data, fall back to expanding month data.
fn resolve_weeks(weeks: &Option<Vec<i32>>, months: &Option<Vec<i32>>) -> Option<Vec<i32>> {
    if let Some(w) = weeks {
        if !w.is_empty() {
            return Some(w.clone());
        }
    }
    months_to_weeks(months)
}

#[component]
pub fn PlantingCalendar(
    indoor_sowing_months: Option<Vec<i32>>,
    direct_sowing_months: Option<Vec<i32>>,
    transplanting_months: Option<Vec<i32>>,
    glasshouse_months: Option<Vec<i32>>,
    harvesting_months: Option<Vec<i32>>,
    indoor_sowing_weeks: Option<Vec<i32>>,
    direct_sowing_weeks: Option<Vec<i32>>,
    transplanting_weeks: Option<Vec<i32>>,
    glasshouse_weeks: Option<Vec<i32>>,
    harvesting_weeks: Option<Vec<i32>>,
) -> Element {
    let rows: Vec<(&str, &str, Option<Vec<i32>>)> = vec![
        ("Indoor Sowing", "cal-indoor", resolve_weeks(&indoor_sowing_weeks, &indoor_sowing_months)),
        ("Direct Sowing", "cal-direct", resolve_weeks(&direct_sowing_weeks, &direct_sowing_months)),
        ("Transplanting", "cal-transplant", resolve_weeks(&transplanting_weeks, &transplanting_months)),
        ("Glasshouse", "cal-glass", resolve_weeks(&glasshouse_weeks, &glasshouse_months)),
        ("Harvesting", "cal-harvest", resolve_weeks(&harvesting_weeks, &harvesting_months)),
    ];

    let has_data = rows.iter().any(|(_, _, w)| w.is_some());
    if !has_data {
        return rsx! { p { class: "empty", "No planting calendar data." } };
    }

    rsx! {
        div { class: "planting-calendar week-calendar",
            // Month header spanning groups of weeks
            div { class: "wcal-month-row",
                div { class: "wcal-label" }
                for (i, label) in MONTH_LABELS.iter().enumerate() {
                    {
                        let (start, end) = MONTH_WEEK_RANGES[i];
                        let span = (end - start + 1) as usize;
                        rsx! {
                            div {
                                class: "wcal-month-header",
                                style: "grid-column: span {span};",
                                "{label}"
                            }
                        }
                    }
                }
            }
            // Data rows
            for (name, class, weeks) in rows.iter() {
                if weeks.is_some() {
                    div { class: "wcal-row",
                        div { class: "wcal-label", "{name}" }
                        for week in 1..=52i32 {
                            {
                                let active = weeks.as_ref()
                                    .map(|w| w.contains(&week))
                                    .unwrap_or(false);
                                rsx! {
                                    div {
                                        class: if active { format!("wcal-cell {class} active") } else { "wcal-cell".to_string() },
                                        title: "W{week}",
                                    }
                                }
                            }
                        }
                    }
                }
            }
            // Legend
            div { class: "wcal-legend",
                div { class: "wcal-legend-item",
                    div { class: "wcal-legend-swatch cal-indoor" }
                    span { "Indoor Sowing" }
                }
                div { class: "wcal-legend-item",
                    div { class: "wcal-legend-swatch cal-direct" }
                    span { "Direct Sowing" }
                }
                div { class: "wcal-legend-item",
                    div { class: "wcal-legend-swatch cal-transplant" }
                    span { "Transplanting" }
                }
                div { class: "wcal-legend-item",
                    div { class: "wcal-legend-swatch cal-glass" }
                    span { "Glasshouse" }
                }
                div { class: "wcal-legend-item",
                    div { class: "wcal-legend-swatch cal-harvest" }
                    span { "Harvesting" }
                }
            }
        }
    }
}