"""Export study artifacts: final sheet, Anki CSV."""

from __future__ import annotations

import csv
import io
from typing import Any

from plane_mode_scholar.core.config import DEFAULT_USER_ID
from plane_mode_scholar.memory.scheduler import get_due_reviews
from plane_mode_scholar.storage.sqlite_store import SQLiteStore
from plane_mode_scholar.study.mastery import MasteryTracker


def build_final_sheet_markdown(
    store: SQLiteStore,
    pack_id: str,
    user_id: str = DEFAULT_USER_ID,
) -> str:
    pack = store.get_pack(pack_id)
    mastery = MasteryTracker(store)
    due = get_due_reviews(store, pack_id, user_id)
    weak = mastery.get_weak_topics(pack_id)
    topics = store.list_topics(pack_id)
    misconceptions = [
        m for m in store.list_memories(pack_id=pack_id, user_id=user_id, status="active")
        if m.type.value == "misconception"
    ]

    lines = [
        f"# Final sheet — {pack.name if pack else pack_id}",
        "",
        "## Must-review (due now)",
    ]
    if due:
        for m in due[:8]:
            lines.append(f"- {m.content}")
    else:
        lines.append("- None due — great job!")

    lines.append("")
    lines.append("## Weak topics")
    if weak:
        for w in weak[:6]:
            lines.append(f"- **{w['name']}** ({int(w.get('mastery', 0) * 100)}%)")
    else:
        lines.append("- Complete quizzes to identify weak areas.")

    lines.append("")
    lines.append("## Common gaps")
    if misconceptions:
        for m in misconceptions[:6]:
            lines.append(f"- {m.content[:120]}")
    else:
        lines.append("- No recorded misconceptions yet.")

    lines.append("")
    lines.append("## Syllabus checklist")
    for t in topics[:12]:
        lines.append(f"- [ ] {t.name}")

    lines.append("")
    lines.append("---")
    lines.append("*Generated by Plane Mode Scholar — study offline, remember on landing.*")
    return "\n".join(lines)


def build_anki_csv(
    store: SQLiteStore,
    pack_id: str,
    user_id: str = DEFAULT_USER_ID,
) -> str:
    """Anki-compatible CSV: front, back, tags."""
    buf = io.StringIO()
    writer = csv.writer(buf, quoting=csv.QUOTE_MINIMAL)
    writer.writerow(["Front", "Back", "Tags"])

    memories = store.list_memories(pack_id=pack_id, user_id=user_id, status="active")
    for mem in memories:
        if mem.type.value in ("misconception", "review_item", "open_loop"):
            front = mem.content[:200]
            if mem.type.value == "misconception" and " instead of " in mem.content:
                parts = mem.content.split(" instead of ")
                back = parts[-1].strip("'") if parts else mem.content
            else:
                back = mem.content
            tags = " ".join(t for t in mem.tags[:5] if not t.startswith(("due:", "interval:", "reps:")))
            writer.writerow([front, back[:300], tags or mem.type.value])

    chunks = store.list_chunks(pack_id)[:20]
    for chunk in chunks:
        text = chunk.text.strip()
        if len(text) < 40:
            continue
        sentences = [s.strip() for s in text.split(".") if len(s.strip()) > 25]
        if sentences:
            front = f"What does {chunk.source_file} say about this topic?"
            back = sentences[0][:300]
            writer.writerow([front, back, f"chunk {chunk.source_file}"])

    return buf.getvalue()


def build_final_sheet_html(
    store: SQLiteStore,
    pack_id: str,
    user_id: str = DEFAULT_USER_ID,
) -> str:
    md = build_final_sheet_markdown(store, pack_id, user_id)
    body = md.replace("\n## ", "\n<h2>").replace("\n- ", "\n<li>")
    body = body.replace("# ", "<h1>").replace("**", "<strong>", 1)
    return f'<div class="pms-card pms-final-sheet"><pre class="pms-sheet">{md}</pre></div>'