import unittest
from unittest.mock import patch

import database


class FakeResponse:
    def __init__(self, data=None):
        self.data = data or []


class FakeRpc:
    def __init__(self, client, params):
        self.client = client
        self.params = params

    def execute(self):
        if self.client.fail_rpc:
            raise RuntimeError("rpc failed")

        saved = []
        for row in self.params["p_records"]:
            key = (row["plant_id"], row["date"])
            existing = self.client.daily.get(key)
            incoming = row["total_generation"]
            if (
                existing is None
                or self.params["p_allow_decrease"]
                or incoming > existing
            ):
                self.client.daily[key] = incoming
            saved.append({**row, "total_generation": self.client.daily[key]})
        self.client.rpc_calls.append(self.params)
        return FakeResponse(saved)


class FakeQuery:
    def __init__(self, client, table_name):
        self.client = client
        self.table_name = table_name
        self.action = None
        self.payload = None
        self.filters = {}

    def select(self, _columns):
        self.action = "select"
        return self

    def upsert(self, payload, on_conflict=None):
        self.action = "upsert"
        self.payload = payload
        self.on_conflict = on_conflict
        return self

    def eq(self, column, value):
        self.filters[column] = ("eq", value)
        return self

    def in_(self, column, values):
        self.filters[column] = ("in", set(values))
        return self

    def gte(self, column, value):
        self.filters[f"{column}_gte"] = ("gte", value)
        return self

    def lte(self, column, value):
        self.filters[f"{column}_lte"] = ("lte", value)
        return self

    def execute(self):
        if self.client.fail_select and self.action == "select":
            raise RuntimeError("select failed")

        if self.action == "select" and self.table_name == "daily_stats":
            rows = []
            for (plant_id, date), value in self.client.daily.items():
                if "plant_id" in self.filters and plant_id != self.filters["plant_id"][1]:
                    continue
                if "date" in self.filters and date not in self.filters["date"][1]:
                    continue
                if "date_gte" in self.filters and date < self.filters["date_gte"][1]:
                    continue
                if "date_lte" in self.filters and date > self.filters["date_lte"][1]:
                    continue
                rows.append({
                    "plant_id": plant_id,
                    "date": date,
                    "total_generation": value,
                })
            return FakeResponse(rows)

        if self.action == "upsert" and self.table_name == "daily_stats":
            for row in self.payload:
                self.client.daily[(row["plant_id"], row["date"])] = row["total_generation"]
            self.client.daily_upserts.append(self.payload)
            return FakeResponse(self.payload)

        if self.action == "upsert" and self.table_name == "monthly_stats":
            self.client.monthly_upserts.append(self.payload)
            return FakeResponse(self.payload)

        raise AssertionError(f"unexpected query: {self.table_name} {self.action}")


class FakeClient:
    def __init__(self, daily=None, fail_rpc=False):
        self.daily = daily or {}
        self.fail_select = False
        self.fail_rpc = fail_rpc
        self.daily_upserts = []
        self.monthly_upserts = []
        self.rpc_calls = []

    def table(self, table_name):
        return FakeQuery(self, table_name)

    def rpc(self, function_name, params):
        if function_name != "upsert_daily_stats":
            raise AssertionError(function_name)
        return FakeRpc(self, params)


class DatabaseHistoryTest(unittest.TestCase):
    def save_daily(self, client, generation):
        with patch.object(database, "get_supabase_client", return_value=client):
            return database.save_history([{
                "plant_id": "plant-a",
                "date": "2026-08-05",
                "generation_kwh": generation,
            }], "daily")

    def test_existing_positive_value_is_not_replaced_by_zero(self):
        client = FakeClient({("plant-a", "2026-08-05"): 100.0})

        result = self.save_daily(client, 0.0)

        self.assertTrue(result)
        self.assertEqual(client.daily[("plant-a", "2026-08-05")], 100.0)
        self.assertEqual(client.daily_upserts, [])
        self.assertEqual(client.rpc_calls[0]["p_source"], "history")
        self.assertFalse(client.rpc_calls[0]["p_allow_decrease"])

    def test_larger_value_updates_existing_daily_stat(self):
        client = FakeClient({("plant-a", "2026-08-05"): 100.0})

        result = self.save_daily(client, 120.0)

        self.assertTrue(result)
        self.assertEqual(client.daily[("plant-a", "2026-08-05")], 120.0)
        self.assertEqual(len(client.rpc_calls), 1)

    def test_rpc_failure_prevents_write(self):
        client = FakeClient(fail_rpc=True)

        result = self.save_daily(client, 120.0)

        self.assertFalse(result)
        self.assertEqual(client.rpc_calls, [])

    def test_negative_generation_is_rejected(self):
        client = FakeClient()

        result = self.save_daily(client, -1.0)

        self.assertFalse(result)
        self.assertEqual(client.rpc_calls, [])


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