"""JSON-from-ag-monitor → markdown helpers.

One function per @mcp.tool. Markdown is what FastMCP tools return; Claude /
OpenWebUI render it nicely. Cents → dollars formatting is centralized here so
all tools use the same precision (4 decimals for $/bu, 2 decimals for $/ton).
"""

from __future__ import annotations

from typing import Optional


def _bu(cents: Optional[int]) -> str:
    if cents is None:
        return "—"
    return f"${cents / 100:.4f}"


def _ton(cents: Optional[int]) -> str:
    if cents is None:
        return "—"
    return f"${cents / 100:.2f}"


def _basis(cents: Optional[int]) -> str:
    if cents is None:
        return "—"
    sign = "+" if cents >= 0 else ""
    return f"{sign}{cents / 100:.2f}"


def _delta_arrow(cents: Optional[int]) -> str:
    if cents is None or cents == 0:
        return "—"
    return "▲" if cents > 0 else "▼"


# ---------- best_local_bid ----------


def fmt_best(commodity: str, payload: dict) -> str:
    best = payload.get("best")
    today = payload.get("today")
    if not best:
        return (
            f"### Best place to sell {commodity} today ({today})\n\n"
            f"No current-month {commodity} bids posted across the tracked sources.\n"
        )
    return (
        f"### Best place to sell {commodity} today ({today})\n\n"
        f"**{best['source_name']}** — delivery **{best['delivery']}** — "
        f"bid **{_bu(best['bid_cents'])}/bu** (basis {_basis(best.get('basis_cents'))}, "
        f"futures {best.get('futures_contract') or '—'})\n\n"
        f"_Fetched {best.get('fetched_at') or '?'}_\n"
    )


# ---------- inputs / fertilizer ----------


def fmt_inputs(payload: dict) -> str:
    rows = payload.get("rows") or []
    product = payload.get("product")
    title = f"### {product.upper()} prices" if product else "### Fertilizer + lime prices"
    if not rows:
        scope = product or "any tracked input"
        return f"{title}\n\nNo {scope} prices on file.\n"
    lines = [
        title, "",
        "| Source | Product | Delivery | Price ($/ton) | Fetched |",
        "|---|---|---|---:|---|",
    ]
    for r in rows:
        lines.append(
            f"| {r['source_name']} | {r.get('display_name') or r['commodity']} | "
            f"{r['delivery']} | {_ton(r.get('bid_cents'))} | {r.get('fetched_at') or '?'} |"
        )
    return "\n".join(lines) + "\n"


# ---------- latest snapshot ----------


def fmt_latest(payload: dict) -> str:
    rows = payload.get("rows") or []
    if not rows:
        return "### Latest prices\n\nNo rows match those filters.\n"
    lines = [
        "### Latest prices", "",
        "| Source | Commodity | Delivery | Bid | Basis | Futures | Fetched |",
        "|---|---|---|---:|---:|---|---|",
    ]
    for r in rows:
        unit_fmt = _ton if r.get("commodity_kind") == "fertilizer" else _bu
        lines.append(
            f"| {r['source_name']} | {r.get('display_name') or r['commodity']} | "
            f"{r['delivery']} | {unit_fmt(r.get('bid_cents'))} | "
            f"{_basis(r.get('basis_cents'))} | {r.get('futures_contract') or '—'} | "
            f"{r.get('fetched_at') or '?'} |"
        )
    return "\n".join(lines) + "\n"


# ---------- price history ----------


def fmt_history(payload: dict, max_rows: int = 60) -> str:
    rows = payload.get("rows") or []
    commodity = payload.get("commodity")
    days = payload.get("days")
    if not rows:
        return f"### {commodity} history ({days}d)\n\nNo samples in the window.\n"

    # Per (source, delivery) trend annotation: first vs last sample.
    series: dict[tuple, list[dict]] = {}
    for r in rows:
        series.setdefault((r["source_name"], r["delivery"]), []).append(r)

    lines = [f"### {commodity} price history — last {days} days", ""]
    for (src, dlv), pts in sorted(series.items()):
        if not pts:
            continue
        first = pts[0].get("bid_cents")
        last = pts[-1].get("bid_cents")
        delta = (last - first) if (first is not None and last is not None) else None
        arrow = _delta_arrow(delta)
        lines.append(
            f"- **{src}** / {dlv}: {len(pts)} samples · "
            f"{_bu(first)} → {_bu(last)} {arrow} {_basis(delta) if delta is not None else ''}".rstrip()
        )

    # If the history is shallow include the raw rows too (helpful for charts).
    if sum(len(p) for p in series.values()) <= max_rows:
        lines.extend([
            "",
            "| Time | Source | Delivery | Bid | Basis |",
            "|---|---|---|---:|---:|",
        ])
        for r in rows[-max_rows:]:
            lines.append(
                f"| {r['fetched_at']} | {r['source_name']} | {r['delivery']} | "
                f"{_bu(r.get('bid_cents'))} | {_basis(r.get('basis_cents'))} |"
            )
    return "\n".join(lines) + "\n"


# ---------- sources / health ----------


def fmt_sources(payload: dict) -> str:
    src = payload.get("sources") or []
    if not src:
        return "### Sources\n\nNo active sources.\n"
    lines = [
        "### Tracked sources", "",
        "| Source | Kind | Last success | Consecutive failures | Last error |",
        "|---|---|---|---:|---|",
    ]
    for s in src:
        lines.append(
            f"| {s['name']} | {s['kind']} | {s.get('last_success_at') or '—'} | "
            f"{s.get('consecutive_failures') or 0} | {s.get('last_error') or ''} |"
        )
    return "\n".join(lines) + "\n"


def fmt_health(payload: dict) -> str:
    src = payload.get("sources") or []
    healthy, stale, down = [], [], []
    for s in src:
        n = s.get("consecutive_failures") or 0
        if n >= 3:
            down.append(s)
        elif not s.get("last_success_at"):
            stale.append(s)
        else:
            healthy.append(s)
    lines = ["### Source health", ""]
    lines.append(f"- ✅ Healthy: **{len(healthy)}**")
    lines.append(f"- ⚠ Stale (never succeeded): **{len(stale)}**")
    lines.append(f"- ❌ Down (3+ consecutive failures): **{len(down)}**")
    if stale or down:
        lines.append("")
        lines.append("| Source | State | Last success | Failures | Error |")
        lines.append("|---|---|---|---:|---|")
        for s in stale + down:
            state = "stale" if s in stale else "down"
            lines.append(
                f"| {s['name']} | {state} | {s.get('last_success_at') or '—'} | "
                f"{s.get('consecutive_failures') or 0} | "
                f"{(s.get('last_error') or '')[:80]} |"
            )
    return "\n".join(lines) + "\n"


# ---------- list helpers ----------


def fmt_deliveries(payload: dict) -> str:
    commodity = payload.get("commodity")
    labels = payload.get("deliveries") or []
    if not labels:
        return f"### {commodity} deliveries\n\nNo posted deliveries.\n"
    return (
        f"### Posted delivery labels for {commodity}\n\n"
        + "\n".join(f"- {x}" for x in labels)
        + "\n"
    )


def fmt_commodities() -> str:
    return (
        "### Tracked commodities\n\n"
        "- **corn** ($/bu)\n"
        "- **soy** — soybeans ($/bu)\n"
        "- **wheat** ($/bu) — tracked but excluded from daily brief emails\n"
        "- **map** — MAP 11-52-0 ($/ton)\n"
        "- **potash** — Potash 0-0-60 ($/ton)\n"
        "- **lime** ($/ton)\n"
    )


# ---------- today's summary ----------


def fmt_summary(payload: dict) -> str:
    today = payload.get("today")
    prev = payload.get("prev_trading_day")
    lines = [f"### Market summary — today {today} vs prev trading day {prev}", ""]
    for c in payload.get("commodities", []):
        f = c.get("futures") or {}
        chg = f.get("change_cents")
        arrow = _delta_arrow(chg)
        lines.append(
            f"**{c['display_name']}** — CBOT {f.get('contract','?')} "
            f"last {_bu(f.get('today_last_cents'))}, prev close "
            f"{_bu(f.get('prev_close_cents'))} {arrow} {_basis(chg) if chg is not None else ''}"
        )
        bft = c.get("best_for_today")
        if bft:
            lines.append(
                f"  · Best for today's delivery ({bft['delivery']}): "
                f"**{bft['source_name']}** @ {_bu(bft['bid_cents'])} "
                f"(basis {_basis(bft.get('basis_cents'))})"
            )
        else:
            lines.append("  · No current-month local bid posted.")
        lines.append("")
    return "\n".join(lines).rstrip() + "\n"