"""
🌱 Canteen Seed Import — Web UX Server

FastAPI server wrapping the seed import pipeline:
  Upload Excel → Preview parse → Import with backup → View report

Usage:
    cd ~/projects/canteen-seed-import
    python3 web/server.py --port 8091
"""

import argparse
import csv
import glob
import gzip
import io
import json
import os
import shutil
import sys
import tempfile
import traceback
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional

from fastapi import FastAPI, HTTPException, Query, Request, UploadFile, File
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse, JSONResponse, Response
from fastapi.staticfiles import StaticFiles

# ─── Import pipeline modules (relative to project root) ──────────────────────

PROJECT_ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(PROJECT_ROOT))

from parser import parse_excel
from db_writer import write_seed, write_update, ALL_COLUMNS, PRESERVE_FIELDS, AUTO_FIELDS
from backup import backup as do_backup, compare as compare_backup


# ─── Helpers ──────────────────────────────────────────────────────────────────


def _list_backup_files() -> list[dict]:
    """List backup files in the seed-data directory."""
    files = sorted(glob.glob(str(PROJECT_ROOT / "seed-data" / "backup_*.json.gz")), reverse=True)
    result = []
    for f in files:
        try:
            with gzip.open(f, "rb") as gz:
                meta = json.loads(gz.read().decode("utf-8"))
            result.append({
                "path": f,
                "filename": os.path.basename(f),
                "created": meta.get("created", "unknown"),
                "records": len(meta.get("records", [])),
                "fields": meta.get("fields", []),
            })
        except Exception:
            mtime = os.path.getmtime(f)
            result.append({
                "path": f,
                "filename": os.path.basename(f),
                "created": datetime.fromtimestamp(mtime).isoformat(),
                "records": 0,
                "fields": [],
            })
    return result

# ─── Config ──────────────────────────────────────────────────────────────────

DEFAULT_DB_PATH = str(PROJECT_ROOT / "seed-data" / "assets.db")
DEFAULT_SEED_DIR = str(PROJECT_ROOT / "seed-data")
UPLOAD_DIR = Path("/tmp/canteen-import-uploads")
REPORT_PATH = Path(DEFAULT_SEED_DIR) / "validation_report.md"
HEADERS_FILE = Path(DEFAULT_SEED_DIR) / "headers_modified.csv"
REFERENCE_FILE = Path(DEFAULT_SEED_DIR) / "reference_handbook.md"

UPLOAD_DIR.mkdir(parents=True, exist_ok=True)

# In-memory state for the current session
_session_state = {
    "machines": None,       # parsed machine list
    "file_name": None,      # uploaded file name
    "parse_stats": None,    # parse summary stats
    "last_import": None,    # result of last import
    "last_backup": None,    # path to last backup
}

# ─── App ─────────────────────────────────────────────────────────────────────

app = FastAPI(title="Canteen Seed Import Tool")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)


# ─── Helpers ─────────────────────────────────────────────────────────────────


def _make_serializable(obj):
    """Convert any object to JSON-serializable form."""
    if obj is None:
        return None
    if isinstance(obj, (str, int, float, bool)):
        return obj
    if isinstance(obj, datetime):
        return obj.isoformat()
    if isinstance(obj, (list, tuple)):
        return [_make_serializable(x) for x in obj]
    if isinstance(obj, dict):
        return {k: _make_serializable(v) for k, v in obj.items()}
    return str(obj)


def _parse_stats(machines: list) -> dict:
    """Build summary stats from parsed machines."""
    total = len(machines)
    disney = sum(1 for m in machines if m.get("is_disney"))
    unknown = sum(1 for m in machines if m.get("is_unknown_machine"))
    ocr = sum(1 for m in machines if m.get("serial_ocr_corrected"))
    hi = sum(1 for m in machines if m.get("priority") == "High")
    mid = sum(1 for m in machines if m.get("priority") == "Mid")
    low = sum(1 for m in machines if m.get("priority") == "Low")

    # Telemetry breakdown
    telemetry = {}
    for m in machines:
        prov = m.get("telemetry_provider", "None") or "None"
        telemetry[prov] = telemetry.get(prov, 0) + 1

    # Class breakdown
    classes = {}
    for m in machines:
        cls = m.get("class", "Unknown") or "Unknown"
        classes[cls] = classes.get(cls, 0) + 1

    return {
        "total": total,
        "disney": disney,
        "unknown_machines": unknown,
        "ocr_corrections": ocr,
        "priority": {"High": hi, "Mid": mid, "Low": low},
        "telemetry": telemetry,
        "classes": classes,
    }


def _format_number(n):
    """Format a number with commas."""
    if n is None:
        return "—"
    return f"{n:,}"


# ─── API Routes ──────────────────────────────────────────────────────────────


@app.get("/api/health")
async def health():
    return {"status": "ok", "time": datetime.now(timezone.utc).isoformat()}


@app.get("/api/status")
async def status():
    """Dashboard stats: DB health, machine counts, GPS coverage."""
    db_path = DEFAULT_DB_PATH
    result = {
        "db_path": db_path,
        "exists": os.path.exists(db_path),
        "total_machines": 0,
        "by_class": {},
        "by_make": {},
        "by_priority": {},
        "gps_coverage": {"with_gps": 0, "without_gps": 0},
        "last_modified": None,
        "last_backup": None,
        "backup_count": 0,
    }
    if not result["exists"]:
        return result

    if os.path.exists(db_path):
        mtime = os.path.getmtime(db_path)
        result["last_modified"] = datetime.fromtimestamp(mtime).isoformat()

    try:
        import sqlite3
        conn = sqlite3.connect(db_path)
        conn.row_factory = sqlite3.Row
        cur = conn.cursor()

        cur.execute("SELECT COUNT(*) as c FROM assets")
        result["total_machines"] = cur.fetchone()["c"]

        cur.execute("SELECT COALESCE(NULLIF(class,''),'Unknown') as cls, COUNT(*) as c FROM assets GROUP BY cls ORDER BY c DESC")
        result["by_class"] = {r["cls"]: r["c"] for r in cur.fetchall()}

        cur.execute("SELECT COALESCE(NULLIF(make,''),'Unknown') as mk, COUNT(*) as c FROM assets GROUP BY mk ORDER BY c DESC")
        result["by_make"] = {r["mk"]: r["c"] for r in cur.fetchall()}

        cur.execute("SELECT COALESCE(NULLIF(priority,''),'None') as pri, COUNT(*) as c FROM assets GROUP BY pri ORDER BY pri")
        result["by_priority"] = {r["pri"]: r["c"] for r in cur.fetchall()}

        cur.execute("SELECT COUNT(*) as c FROM assets WHERE latitude IS NOT NULL AND latitude != 0")
        result["gps_coverage"]["with_gps"] = cur.fetchone()["c"]
        result["gps_coverage"]["without_gps"] = result["total_machines"] - result["gps_coverage"]["with_gps"]

        conn.close()
    except Exception:
        pass

    backups = _list_backup_files()
    result["backup_count"] = len(backups)
    if backups:
        result["last_backup"] = backups[0].get("created", "")
    return result


@app.get("/api/backups")
async def list_backups():
    """List available backup files."""
    return {"backups": _list_backup_files()}


@app.get("/api/columns")
async def columns():
    """Return column definitions: which are auto vs preserve vs primary key."""
    return {
        "all": ALL_COLUMNS,
        "preserve": sorted(PRESERVE_FIELDS),
        "auto": sorted(AUTO_FIELDS),
        "primary_key": "machine_id",
    }


@app.get("/api/headers")
async def headers():
    """Return the header mapping CSV as JSON."""
    if not HEADERS_FILE.exists():
        return {"headers": [], "note": f"{HEADERS_FILE} not found"}
    rows = []
    with open(HEADERS_FILE, newline="", encoding="utf-8") as f:
        reader = csv.DictReader(f)
        for row in reader:
            rows.append(row)
    return {"headers": rows, "count": len(rows)}


@app.get("/api/reference")
async def reference():
    """Return the reference handbook markdown."""
    if not REFERENCE_FILE.exists():
        return {"content": "", "note": f"{REFERENCE_FILE} not found"}
    with open(REFERENCE_FILE, encoding="utf-8") as f:
        content = f.read()
    return {"content": content, "size": len(content)}


@app.post("/api/upload")
async def upload(file: UploadFile = File(...)):
    """Upload an Excel file and parse it. Returns preview + stats."""
    if not file.filename:
        raise HTTPException(400, "No file provided")

    suffix = Path(file.filename).suffix.lower()
    if suffix not in (".xlsx", ".xls", ".csv"):
        raise HTTPException(400, f"Unsupported file type: {suffix}. Use .xlsx, .xls, or .csv")

    # Save to temp
    upload_path = UPLOAD_DIR / f"{datetime.now(timezone.utc).strftime('%Y%m%d_%H%M%S')}_{file.filename}"
    with open(upload_path, "wb") as f:
        content = await file.read()
        f.write(content)

    # Parse
    try:
        machines = parse_excel(str(upload_path))
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(500, f"Parse error: {e}")

    # Build stats
    stats = _parse_stats(machines)

    # Build preview (first 50 rows, key columns)
    preview_cols = [
        "machine_id", "serial_number", "name", "class", "make", "model",
        "company", "place", "building_name", "floor", "zone",
        "priority", "telemetry_provider", "disney_park", "is_disney",
        "yearly_sales", "has_cashless", "alerts_summary",
    ]
    preview = []
    for m in machines[:50]:
        row = {}
        for col in preview_cols:
            row[col] = _make_serializable(m.get(col))
        preview.append(row)

    # Store in session
    _session_state["machines"] = machines
    _session_state["file_name"] = file.filename
    _session_state["parse_stats"] = stats

    # Cleanup temp file (keep parsed data in memory)
    try:
        os.unlink(str(upload_path))
    except OSError:
        pass

    return {
        "file_name": file.filename,
        "stats": stats,
        "preview": preview,
        "preview_count": len(preview),
        "total_rows": len(machines),
        "columns_previewed": preview_cols,
    }


@app.post("/api/import")
async def run_import(
    mode: str = Query("seed", pattern="^(seed|update)$"),
    backup: bool = Query(True),
    db_path: str = Query(DEFAULT_DB_PATH),
):
    """Run the import — seed or update mode. Optionally backup first."""
    if _session_state["machines"] is None:
        raise HTTPException(400, "No data parsed. Upload a file first.")

    machines = _session_state["machines"]
    backup_path = None

    # Backup if requested
    if backup and os.path.exists(db_path):
        try:
            backup_path = do_backup(db_path)
            _session_state["last_backup"] = backup_path
        except Exception as e:
            traceback.print_exc()
            # Don't fail the whole import if backup fails
            backup_path = f"ERROR: {e}"

    # Run import
    try:
        if mode == "seed":
            stats = write_seed(machines, db_path)
        else:
            stats = write_update(machines, db_path)
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(500, f"Import error: {e}")

    _session_state["last_import"] = {
        "mode": mode,
        "db_path": db_path,
        "stats": stats,
        "backup_path": backup_path,
        "time": datetime.now(timezone.utc).isoformat(),
    }

    return {
        "mode": mode,
        "stats": stats,
        "backup_path": backup_path,
        "machine_count": len(machines),
    }


@app.get("/api/report")
async def report(refresh: bool = Query(False)):
    """Return the latest validation report."""
    if not REPORT_PATH.exists():
        return {"content": "", "note": "No report generated yet. Run an import first."}
    with open(REPORT_PATH, encoding="utf-8") as f:
        content = f.read()
    return {
        "content": content,
        "size": len(content),
        "path": str(REPORT_PATH),
    }


@app.get("/api/session")
async def session():
    """Return current session state."""
    return {
        "file_name": _session_state["file_name"],
        "parse_stats": _session_state["parse_stats"],
        "last_import": _session_state["last_import"],
        "last_backup": _session_state["last_backup"],
        "has_data": _session_state["machines"] is not None,
        "machine_count": len(_session_state["machines"]) if _session_state["machines"] else 0,
    }


@app.post("/api/backup")
async def api_backup(db_path: str = Query(DEFAULT_DB_PATH)):
    """Create a backup of the current database."""
    if not os.path.exists(db_path):
        raise HTTPException(404, f"Database not found: {db_path}")
    try:
        path = do_backup(db_path)
        _session_state["last_backup"] = path
        return {"backup_path": path, "status": "ok"}
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(500, f"Backup error: {e}")


@app.post("/api/compare")
async def api_compare(
    backup_path: str = Query(...),
    db_path: str = Query(DEFAULT_DB_PATH),
):
    """Compare a backup against the live database."""
    if not os.path.exists(backup_path):
        raise HTTPException(404, f"Backup not found: {backup_path}")
    try:
        changes = compare_backup(backup_path, db_path)
        return {"changes": changes, "backup": backup_path, "db": db_path}
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(500, f"Compare error: {e}")


@app.post("/api/backup/restore")
async def api_restore(
    backup_path: str = Query(...),
    db_path: str = Query(DEFAULT_DB_PATH),
):
    """Restore GPS/photo fields from a backup."""
    if not os.path.exists(backup_path):
        raise HTTPException(404, f"Backup not found: {backup_path}")
    try:
        from backup import restore as do_restore
        do_restore(backup_path, db_path)
        return {"status": "ok", "restored_from": os.path.basename(backup_path), "db": db_path}
    except Exception as e:
        traceback.print_exc()
        raise HTTPException(500, f"Restore error: {e}")


# ─── Static files ─────────────────────────────────────────────────────────────

STATIC_DIR = Path(__file__).parent / "static"
STATIC_DIR.mkdir(parents=True, exist_ok=True)

if STATIC_DIR.exists():
    app.mount("/", StaticFiles(directory=str(STATIC_DIR), html=True), name="static")


# ─── Entry point ─────────────────────────────────────────────────────────────

if __name__ == "__main__":
    import uvicorn

    parser = argparse.ArgumentParser(description="Canteen Seed Import Web Server")
    parser.add_argument("--port", type=int, default=8091, help="Port to listen on")
    parser.add_argument("--host", type=str, default="0.0.0.0", help="Host to bind to")
    args = parser.parse_args()

    print(f"🌱 Canteen Seed Import Web Server")
    print(f"   http://localhost:{args.port}")
    print(f"   DB: {DEFAULT_DB_PATH}")
    print(f"   Seed dir: {DEFAULT_SEED_DIR}")
    uvicorn.run(app, host=args.host, port=args.port, log_level="info")