from abc import abstractmethod
import collections
from typing import Any, Dict, List, Optional, Self

import comfyrecipes.settings as settings
import comfyrecipes.issues as issues

import jsonschema

class Context:
    def __init__(self) -> None:
        self.settings = settings.Settings()
        self.units: AUnits = FakeUnits(self)
        self.default_unit = Unit(self, "piece", [], [])
        self.ingredients: AIngredients = FakeIngredients(self)
        self.issues = issues.Issues()

    def load_units(
        self, unitsdct: List[Dict[str, Any]], unitsschema: Dict[str, Any]
    ) -> None:
        self.units = Units(self)
        self.units.units.append(self.default_unit)
        jsonschema.validate(instance=unitsdct, schema=unitsschema)
        self.units.load(unitsdct)
        self.units.validate()

    def load_ingredients(
        self, ingredientsdct: List[Dict[str, Any]], ingredientsschema: Dict[str, Any]
    ) -> None:
        self.ingredients = Ingredients(self)
        jsonschema.validate(instance=ingredientsdct, schema=ingredientsschema)
        self.ingredients.load(ingredientsdct)

    def load_settings(
        self, settingsdct: Dict[str, Any], settingsschema: Dict[str, Any]
    ) -> None:
        jsonschema.validate(instance=settingsdct, schema=settingsschema)
        self.settings.load(settingsdct)

class Element:
    def __init__(self, ctx: Context) -> None:
        self.ctx = ctx

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        return cls(ctx)

class Unit(Element):
    def __init__(
        self,
        ctx: Context,
        name: str,
        conversions: List["Conversion"],
        aliases: List[str],
        dct: Optional[Dict[str, Any]] = None,
    ) -> None:
        super().__init__(ctx)
        self.name = name
        self.conversions = conversions
        self.aliases = aliases
        self.dct = dct

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        # conversions are an empty list which is populated in finish_load
        # which should be ran when all units are registered
        aliases: List[str] = []
        if "aliases" in dct:
            aliases = dct["aliases"]

        return cls(ctx, name=dct["name"], conversions=[], aliases=aliases, dct=dct)

    def finish_load(self) -> None:
        if self.dct is None:
            return
        if "conversions" not in self.dct:
            return
        conversions = []
        for conv in self.dct["conversions"]:
            if "from" in conv:
                raise RuntimeError(
                    "conversions in units.yaml cannot have a from field, it is automatically assigned from the unit name"
                )
            conv["from"] = self.dct["name"]
            conv = Conversion.from_dict(self.ctx, conv)
            conversions.append(conv)

        self.conversions = conversions



class AUnits:
    def __init__(self, ctx: Context) -> None:
        self.ctx = ctx
        self.units: List[Unit] = []

    def load(self, lst: List[Any]) -> None:
        pass

    @abstractmethod
    def get(self, name: str) -> Optional[Unit]:
        ...

    def validate(self) -> None:
        pass


class FakeUnits(AUnits):
    def get(self, name: str) -> Optional[Unit]:
        for unit in self.units:
            if unit.name == name:
                return unit
        unit = Unit(self.ctx, name, [], [])
        self.units.append(unit)
        return unit


class Units(AUnits):
    def load(self, lst: List[Any]) -> None:
        for unitdct in lst:
            unit = Unit.from_dict(self.ctx, unitdct)
            self.units.append(unit)
        for unit in self.units:
            unit.finish_load()

    def get(self, name: str) -> Optional[Unit]:
        for unit in self.units:
            if unit.name == name or name in unit.aliases:
                return unit
        return None

    def validate(self) -> None:
        unitnames = []
        for unit in self.units:
            unitnames.append(unit.name)
        for unitname, num in collections.Counter(unitnames).items():
            if num > 1:
                self.ctx.issues.error(
                    issues.ISSUE_DUPLICATE_UNITS,
                    f"units.yaml: {unitname} should only have one entry, found {num}",
                )

class IngredientInstance(Element):
    def __init__(
        self,
        ctx: Context,
        name: str,
        amount: float,
        unit: Unit,
        alternatives: List["IngredientInstance"],
        note: str,
        price: Optional["PriceDB"],
    ) -> None:
        super().__init__(ctx)
        self.name = name
        self.amount = amount
        self.unit = unit
        self.alternatives = alternatives
        self.note = note
        self.price = price

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        name = dct["name"]

        ingredient = ctx.ingredients.get(name)
        if ingredient is None:
            ctx.issues.error(
                issues.ISSUE_UNKNOWN_INGREDIENT, f"unknown ingredient {dct['name']}"
            )

        amount = 1.0
        if "amount" in dct:
            amount = dct["amount"]

        unit = ctx.default_unit
        if "unit" in dct:
            unitstr = dct["unit"]
            unitx = ctx.units.get(unitstr)
            if unitx is None:
                ctx.issues.error(issues.ISSUE_UNKNOWN_UNIT, "unknown unit {unitstr}")
            else:
                unit = unitx

        note = ""
        if "note" in dct:
            note = dct["note"]

        alternatives = []
        if "or" in dct:
            for ingdct in dct["or"]:
                ing = IngredientInstance.from_dict(ctx, ingdct)
                alternatives.append(ing)

        price = None
        if ingredient is not None:
            price = ingredient.getprice(amount, unit)
        return cls(
            ctx=ctx,
            name=name,
            amount=amount,
            unit=unit,
            alternatives=alternatives,
            note=note,
            price=price,
        )

class StepSection(Element):
    def __init__(self, ctx: Context, title: str, steps: List[str]) -> None:
        self.title = title
        self.steps = steps

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        return cls(ctx, dct["section"], dct["steps"])

class Recipe(Element):
    def __init__(
        self,
        ctx: Context,
        title: str,
        ingredients: List[IngredientInstance],
        subrecipes: List["Recipe"],
        price: Optional["PriceDB"],
        stepsections: List[StepSection],
    ) -> None:
        super().__init__(ctx)
        self.srcpath = ""
        self.outpath = ""
        self.title = title
        self.ingredients = ingredients
        self.subrecipes = subrecipes
        self.price = price
        self.stepsections = stepsections

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        ingredients: List[IngredientInstance] = []
        if "ingredients" in dct:
            for ingdct in dct["ingredients"]:
                ingredient = IngredientInstance.from_dict(ctx, ingdct)
                ingredients.append(ingredient)

        subrecipes: List[Recipe] = []
        if "subrecipes" in dct:
            for partdct in dct["subrecipes"]:
                rp = Recipe.from_dict(ctx, partdct)
                subrecipes.append(rp)

        price: Optional[PriceDB] = None
        pricex: float = 0
        ingswithprice = 0
        ingswithoutprice = 0
        currency = None
        for ing in ingredients:
            if ing.price is None:
                ingswithoutprice += 1
                continue
            ingswithprice += 1
            pricex += ing.price.price
            cur_currency = ing.price.currency
            if currency is None:
                currency = cur_currency
            elif currency != cur_currency:
                # we don't know how to convert currencies yet
                currency = None
                break
        if currency is None or ingswithoutprice != 0 or len(ingredients) == 0:
            price = None
        else:
            price = PriceDB(
                ctx=ctx,
                price=pricex,
                amount=1,
                unit=ctx.default_unit,
                currency=currency,
            )

        stepsections: List[StepSection] = []
        if "steps" in dct:
            defaultstepsection = StepSection(ctx, "default", [])
            stepsections = [defaultstepsection]
            for step in dct["steps"]:
                if isinstance(step, str):
                    defaultstepsection.steps.append(step)
                if isinstance(step, dict):
                    section = StepSection.from_dict(ctx, step)
                    stepsections.append(section)

        return cls(
            ctx=ctx,
            title=dct["title"],
            ingredients=ingredients,
            subrecipes=subrecipes,
            price=price,
            stepsections=stepsections,
        )

class Conversion(Element):
    def __init__(
        self, ctx: Context, fromunit: Unit, tounit: Unit, ratio: float
    ) -> None:
        super().__init__(ctx)
        self.fromunit = fromunit
        self.tounit = tounit
        self.ratio = ratio

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        fromunit = ctx.units.get(dct["from"])
        if fromunit is None:
            raise RuntimeError(f"unit {dct['from']} doesn't exist")

        tounit = ctx.units.get(dct["to"])
        if tounit is None:
            raise RuntimeError(f"unit {dct['to']} doesn't exist")
        return cls(ctx, fromunit, tounit, dct["ratio"])

class Ingredient(Element):
    def __init__(
        self,
        ctx: Context,
        name: str,
        wdid: Optional[int],
        prices: List["PriceDB"],
        conversions: List[Conversion],
        aliases: List[str],
    ) -> None:
        super().__init__(ctx)
        self.name = name
        self.wdid = wdid
        self.prices = prices
        self.conversions = conversions
        self.aliases = aliases

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        wdid = None
        if "wdid" in dct:
            wdid = dct["wdid"]

        prices: List[PriceDB] = []
        if "prices" in dct:
            for pricedct in dct["prices"]:
                prices.append(PriceDB.from_dict(ctx, pricedct))

        conversions: List[Conversion] = []
        if "conversions" in dct:
            for convdct in dct["conversions"]:
                conversion = Conversion.from_dict(ctx, convdct)
                conversions.append(conversion)

        aliases: List[str] = []
        if "aliases" in dct:
            aliases = dct["aliases"]

        return cls(
            ctx,
            name=dct["name"],
            wdid=wdid,
            prices=prices,
            conversions=conversions,
            aliases=aliases,
        )

    def dfs(
        self,
        conversions: Dict[str, Dict[str, float]],
        startname: str,
        endname: str,
        visited: Optional[List[str]] = None,
    ) -> Optional[List[str]]:
        if visited is None:
            visited = []
        if startname == endname:
            return visited + [startname]

        for nextunit in conversions[startname].keys():
            if nextunit in visited:
                continue
            result = self.dfs(conversions, nextunit, endname, visited + [startname])
            if result is not None:
                return result
        return None

    def convert(self, amount: float, unitfrom: Unit, unitto: Unit) -> Optional[float]:
        conversions: Dict[str, Dict[str, float]] = collections.defaultdict(dict)
        # construct node tree
        convs = self.conversions
        for unit in self.ctx.units.units:
            convs += unit.conversions
        for conv in convs:
            fromname = conv.fromunit.name
            toname = conv.tounit.name
            conversions[fromname][toname] = conv.ratio
            conversions[toname][fromname] = 1 / conv.ratio

        # find path between conversions
        path = self.dfs(conversions, unitfrom.name, unitto.name)
        if path is None:
            self.ctx.issues.warn(
                issues.ISSUE_KNOWN_PRICE_UNKNOWN_CONVERSION,
                f"{self.name} has a known price, but conversion {unitfrom.name} -> {unitto.name} not known",
            )
            return None
        assert len(path) != 0
        oldelem = path[0]
        for elem in path[1:]:
            amount *= conversions[oldelem][elem]
            oldelem = elem
        return amount

    def getprice(self, amount: float, unit: Unit) -> Optional["PriceDB"]:
        prices: List[PriceDB] = []
        pricedbs: List[PriceDB] = self.prices
        for entry in pricedbs:
            assert isinstance(entry, PriceDB)
            entryamount: float = entry.amount
            entryprice: float = entry.price
            entryunit: Unit = entry.unit
            price = 0.0
            if entryunit == unit:
                price = (amount / entryamount) * entryprice
            else:
                pricex = self.convert(amount, unit, entryunit)
                if pricex is not None:
                    price = (pricex / entryamount) * entryprice
            newentry = PriceDB(
                self.ctx,
                price=price,
                amount=amount,
                unit=unit,
                currency=entry.currency,
            )
            prices.append(newentry)
        if len(prices) == 0:
            return None
        assert len(prices) == 1
        return prices[0]


class AIngredients:
    def __init__(self, ctx: Context) -> None:
        self.ctx = ctx
        self.ingredients: List[Ingredient] = []

    def load(self, lst: List[Any]) -> None:
        pass

    @abstractmethod
    def get(self, name: str) -> Optional[Ingredient]:
        ...


class FakeIngredients(AIngredients):
    def get(self, name: str) -> Optional[Ingredient]:
        for ing in self.ingredients:
            if ing.name == name:
                return ing
        ing = Ingredient(self.ctx, name, None, [], [], [])
        self.ingredients.append(ing)
        return ing


class Ingredients(AIngredients):
    def load(self, lst: List[Any]) -> None:
        for ingdct in lst:
            ing = Ingredient.from_dict(self.ctx, ingdct)
            self.ingredients.append(ing)

    def get(self, name: str) -> Optional[Ingredient]:
        for ing in self.ingredients:
            if ing.name == name or name in ing.aliases:
                return ing
        return None


class PriceDB(Element):
    def __init__(
        self,
        ctx: Context,
        price: float,
        amount: float,
        unit: Unit,
        currency: Optional[str],
    ) -> None:
        super().__init__(ctx)
        self.price = price
        self.amount = amount
        self.unit = unit
        self.currency = currency

    @classmethod
    def from_dict(cls, ctx: Context, dct: Dict[str, Any]) -> Self:
        price = dct["price"]
        amount = dct["amount"]

        unitstr = dct["unit"]
        unitx = ctx.units.get(unitstr)
        # uses the default unit if unit is not known (this won't be
        # visible to the user since rendering will stop after
        # everything is evaluated)
        unit = ctx.default_unit
        if unitx is None:
            ctx.issues.error(issues.ISSUE_UNKNOWN_UNIT, f"unknown unit {unitstr}")
        else:
            unit = unitx

        currency = ctx.settings.default_currency
        if "currency" in dct:
            currency = dct["currency"]
        return cls(ctx=ctx, price=price, amount=amount, unit=unit, currency=currency)