import csv
import tempfile
import unittest
from pathlib import Path

import analyze_purchases


class AnalyzePurchasesTests(unittest.TestCase):
    def test_analysis_outputs_cover_required_views(self):
        with tempfile.TemporaryDirectory() as tmpdir:
            purchases_csv = Path(tmpdir) / "purchases.csv"
            output_dir = Path(tmpdir) / "analysis"

            fieldnames = [
                "purchase_date",
                "retailer",
                "order_id",
                "catalog_id",
                "catalog_name",
                "category",
                "product_type",
                "net_line_total",
                "line_total",
                "normalized_quantity",
                "normalized_quantity_unit",
                "effective_price",
                "effective_price_unit",
                "store_name",
                "store_number",
                "store_city",
                "store_state",
                "is_fee",
                "is_discount_line",
                "is_coupon_line",
            ]
            with purchases_csv.open("w", newline="", encoding="utf-8") as handle:
                writer = csv.DictWriter(handle, fieldnames=fieldnames)
                writer.writeheader()
                writer.writerows(
                    [
                        {
                            "purchase_date": "2026-03-01",
                            "retailer": "giant",
                            "order_id": "g1",
                            "catalog_id": "cat_banana",
                            "catalog_name": "BANANA",
                            "category": "produce",
                            "product_type": "banana",
                            "net_line_total": "1.29",
                            "line_total": "1.29",
                            "normalized_quantity": "2.19",
                            "normalized_quantity_unit": "lb",
                            "effective_price": "0.589",
                            "effective_price_unit": "lb",
                            "store_name": "Giant",
                            "store_number": "42",
                            "store_city": "Springfield",
                            "store_state": "VA",
                            "is_fee": "false",
                            "is_discount_line": "false",
                            "is_coupon_line": "false",
                        },
                        {
                            "purchase_date": "2026-03-01",
                            "retailer": "giant",
                            "order_id": "g1",
                            "catalog_id": "cat_ice",
                            "catalog_name": "ICE",
                            "category": "frozen",
                            "product_type": "ice",
                            "net_line_total": "3.50",
                            "line_total": "3.50",
                            "normalized_quantity": "20",
                            "normalized_quantity_unit": "lb",
                            "effective_price": "0.175",
                            "effective_price_unit": "lb",
                            "store_name": "Giant",
                            "store_number": "42",
                            "store_city": "Springfield",
                            "store_state": "VA",
                            "is_fee": "false",
                            "is_discount_line": "false",
                            "is_coupon_line": "false",
                        },
                        {
                            "purchase_date": "2026-03-02",
                            "retailer": "costco",
                            "order_id": "c1",
                            "catalog_id": "cat_banana",
                            "catalog_name": "BANANA",
                            "category": "produce",
                            "product_type": "banana",
                            "net_line_total": "1.49",
                            "line_total": "2.98",
                            "normalized_quantity": "3",
                            "normalized_quantity_unit": "lb",
                            "effective_price": "0.4967",
                            "effective_price_unit": "lb",
                            "store_name": "MT VERNON",
                            "store_number": "1115",
                            "store_city": "ALEXANDRIA",
                            "store_state": "VA",
                            "is_fee": "false",
                            "is_discount_line": "false",
                            "is_coupon_line": "false",
                        },
                    ]
                )

            analyze_purchases.main.callback(
                purchases_csv=str(purchases_csv),
                output_dir=str(output_dir),
            )

            expected_files = [
                "item_price_over_time.csv",
                "spend_by_visit.csv",
                "items_per_visit.csv",
                "category_spend_over_time.csv",
                "retailer_store_breakdown.csv",
            ]
            for name in expected_files:
                self.assertTrue((output_dir / name).exists(), name)

            with (output_dir / "spend_by_visit.csv").open(newline="", encoding="utf-8") as handle:
                spend_rows = list(csv.DictReader(handle))
            self.assertEqual("4.79", spend_rows[0]["visit_spend_total"])

            with (output_dir / "items_per_visit.csv").open(newline="", encoding="utf-8") as handle:
                item_rows = list(csv.DictReader(handle))
            self.assertEqual("2", item_rows[0]["item_row_count"])
            self.assertEqual("2", item_rows[0]["distinct_catalog_count"])

            with (output_dir / "category_spend_over_time.csv").open(newline="", encoding="utf-8") as handle:
                category_rows = list(csv.DictReader(handle))
            produce_row = next(row for row in category_rows if row["purchase_date"] == "2026-03-01" and row["category"] == "produce")
            self.assertEqual("1.29", produce_row["category_spend_total"])

            with (output_dir / "retailer_store_breakdown.csv").open(newline="", encoding="utf-8") as handle:
                store_rows = list(csv.DictReader(handle))
            giant_row = next(row for row in store_rows if row["retailer"] == "giant")
            self.assertEqual("1", giant_row["visit_count"])
            self.assertEqual("2", giant_row["item_row_count"])
            self.assertEqual("4.79", giant_row["store_spend_total"])


if __name__ == "__main__":
    unittest.main()