from typing import Dict, List, Any, Optional, Set
import os

import yaml
import jinja2


class Context:
    def __init__(self) -> None:
        self.units = Units()
        self.ingredients = Ingredients(self)


class Unit:
    def __init__(self, name: str) -> None:
        self.name = name


class Units:
    def __init__(self) -> None:
        self.units: List[Unit] = []

    def load(self, lst: List[Any]) -> List[str]:
        assert_list(lst)
        for unit in lst:
            assert_type(unit, "", str)
            self.units.append(Unit(unit))
        return []

    def get(self, name: str) -> Optional[Unit]:
        for unit in self.units:
            if unit.name == name:
                return unit
        raise RuntimeError(f"unit {name} not found")


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

    def load(self, dct: Dict[str, Any]) -> List[str]:
        issues = []
        issues += assert_dict(dct, ["name"], ["wdid", "pricedb", "aliases"])

        assert_type(dct, "name", str)
        self.name = dct["name"]

        self.wdid = -1
        if "wdid" in dct:
            assert_type(dct, "wdid", int)
            self.wdid = dct["wdid"]

        self.pricedb = None
        if "pricedb" in dct:
            assert_list(dct["pricedb"])
            self.pricedb = PriceDBs(self.ctx)
            issues += self.pricedb.load(dct["pricedb"])

        self.aliases = []
        if "aliases" in dct:
            assert_list(dct["aliases"])
            for elem in dct["aliases"]:
                assert_type(elem, "", str)
                self.aliases.append(elem)

        return issues


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

    def load(self, lst: List[Any]) -> List[str]:
        issues = []
        assert_list(lst)
        for ingdct in lst:
            ing = Ingredient(self.ctx)
            issues += ing.load(ingdct)
            self.ingredients.append(ing)
        return issues

    def get(self, name: str) -> Optional[Ingredient]:
        for ing in self.ingredients:
            if ing.name == name or name in ing.aliases:
                return ing
        raise RuntimeError(f"ingredient {name} not found")


class PriceDBs:
    def __init__(self, ctx: Context) -> None:
        self.ctx = ctx
        self.pricedbs: List[PriceDB] = []

    def load(self, lst: List[Any]) -> List[str]:
        issues = []
        assert_list(lst)
        for elem in lst:
            pricedb = PriceDB(self.ctx)
            issues += pricedb.load(elem)
            self.pricedbs.append(pricedb)
        return issues


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

    def load(self, dct: Dict[str, Any]) -> List[str]:
        issues = []
        issues += assert_dict(dct, ["price"], ["amount", "unit"])

        if isinstance(dct["price"], float):
            self.price = dct["price"]
        elif isinstance(dct["price"], int):
            self.price = float(dct["price"])
        else:
            raise RuntimeError(f"{dct['price']} has to be int or float")

        self.amount = 1.0
        if "amount" in dct:
            if isinstance(dct["amount"], float):
                self.amount = dct["amount"]
            elif isinstance(dct["amount"], int):
                self.amount = float(dct["amount"])
            else:
                raise RuntimeError(f"{dct['amount']} has to be int or float")

        self.unit = None
        if "unit" in dct:
            assert_type(dct, "unit", str)
            try:
                self.unit = self.ctx.units.get(dct["unit"])
            except RuntimeError as e:
                issues.append(str(e))
        return issues


class IngredientInstance:
    def __init__(
        self, ctx: Context, defaultamount: float = 1, defaultunit: Optional[Unit] = None
    ) -> None:
        self.ctx = ctx
        self.defaultamount = float(defaultamount)
        self.defaultunit: Optional[Unit] = defaultunit

    def load(self, dct: Dict[str, Any]) -> List[str]:
        issues = []
        issues += assert_dict(dct, ["name"], ["amount", "unit", "note", "or"])

        assert_type(dct, "name", str)
        self.name = dct["name"]

        try:
            self.ingredient = self.ctx.ingredients.get(self.name)
        except RuntimeError as e:
            issues.append(str(e))

        self.amount = self.defaultamount
        if "amount" in dct:
            if isinstance(dct["amount"], float):
                self.amount = dct["amount"]
            elif isinstance(dct["amount"], int):
                self.amount = float(dct["amount"])
            else:
                raise RuntimeError(f"{dct['amount']} has to be int or float")

        self.unit = self.defaultunit
        if "unit" in dct:
            assert_type(dct, "unit", str)
            try:
                self.unit = self.ctx.units.get(dct["unit"])
            except RuntimeError as e:
                issues.append(str(e))
        self.note = ""
        if "note" in dct:
            assert_type(dct, "note", str)
            self.note = dct["note"]

        self.alternatives = []
        if "or" in dct:
            assert_list(dct["or"])
            for ingdct in dct["or"]:
                ingredient = IngredientInstance(
                    self.ctx, defaultamount=self.amount, defaultunit=self.unit
                )
                ingredient.load(ingdct)
                self.alternatives.append(ingredient)

        return issues


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

    def load(self, dct: Dict[str, Any]) -> List[str]:
        issues = []
        issues += assert_dict(dct, ["title", "ingredients", "steps"], [])

        assert_type(dct, "title", str)
        self.title = dct["title"]

        assert_type(dct, "ingredients", list)
        self.ingredients: List[IngredientInstance] = []
        for ing in dct["ingredients"]:
            ingredient = IngredientInstance(self.ctx)
            issues += ingredient.load(ing)
            self.ingredients.append(ingredient)

        assert_type(dct, "steps", list)
        for elem in dct["steps"]:
            assert_type(elem, "", str)
        self.steps: List[str] = dct["steps"]

        return issues


class Recipe:
    def __init__(self, ctx: Context) -> None:
        self.ctx = ctx
        self.parts: List[RecipePart] = []
        self.srcpath = ""
        self.outpath = ""
        self.title = ""

    def load(self, dct: Dict[str, Any]) -> List[str]:
        issues: List[str] = []
        if "parts" in dct:
            assert_dict(dct, ["title"], [])
            assert_type(dct, "title", str)
            self.title = dct["title"]

            assert_list(dct["parts"])
            for partdct in dct["parts"]:
                rp = RecipePart(self.ctx)
                issues += rp.load(partdct)
                self.parts.append(rp)
        else:
            rp = RecipePart(self.ctx)
            issues = rp.load(dct)
            self.parts = [rp]
            self.title = rp.title
        return issues


def assert_dict(
    dct: Dict[str, Any], required_keys: List[str], optional_keys: List[str]
) -> List[str]:
    issues = []
    if not isinstance(dct, dict):
        raise RuntimeError(f"{dct} has to be a dict")
    for reqkey in required_keys:
        if reqkey not in dct:
            issues.append(f"{reqkey} is required")
    extraelems = [x for x in dct.keys() if x not in required_keys + optional_keys]
    if len(extraelems) != 0:
        issues.append(f"{extraelems} not allowed")
    return issues


def assert_type(dct: Dict[str, Any], key: str, type: type) -> None:
    if key == "":
        if not isinstance(dct, type):
            raise RuntimeError(f"{key} has to be a {type}")
    elif key in dct and not isinstance(dct[key], type):
        raise RuntimeError(f"{key} has to be a {type}")


def assert_list(lst: List[Any]) -> None:
    if not isinstance(lst, list):
        raise RuntimeError(f"{lst} has to be a {list}")


class Builder:
    def __init__(self) -> None:
        self.jinjaenv = jinja2.Environment(
            loader=jinja2.FileSystemLoader("templates"),
            autoescape=jinja2.select_autoescape(),
        )
        def numprint(input: int) -> str:
            out = str(input)
            if out.endswith(".0"):
                out = out.split(".")[0]
            if out == "0.5":
                return "1/2"
            elif out == "0.25":
                return "1/4"
            elif out == "0.75":
                return "3/4"
            return out

        self.jinjaenv.filters['numprint'] = numprint
        self.ctx = Context()
        # list of output files that will be built
        self.outfiles: Set[str] = set()

    def load_file(self, file: str) -> Any:
        print(f"loading {file}")
        with open(file, encoding="utf-8") as f:
            ymltxt = f.read()
        return yaml.safe_load(ymltxt)

    def rendertemplate(
        self, templatepath: str, format: str, file: str, args: Any
    ) -> None:
        template = self.jinjaenv.get_template(templatepath)
        print(f"rendering {file}")
        outstr = template.render(args)

        os.makedirs(f"out/{format}", exist_ok=True)

        with open(f"out/{format}/{file}", "w", encoding="utf-8") as f:
            f.write(outstr)
        self.outfiles.add(file)

    def load(self) -> None:
        issues: List[str] = []

        unitsdct = self.load_file("recipes/units.yaml")
        issues += self.ctx.units.load(unitsdct)

        ingredientsdct = self.load_file("recipes/ingredients.yaml")
        issues += self.ctx.ingredients.load(ingredientsdct)

        if len(issues) != 0:
            for issue in issues:
                print("ERROR", issue)
            return

    def run(self) -> None:
        issues = []
        files = []
        for _, _, filesx in os.walk("recipes/recipes"):
            files = filesx
            files.sort()

        recipes: List[Recipe] = []
        for file in files:
            if not file.endswith(".yaml"):
                print(f"unknown extension of {file}")
                continue
            recipe = Recipe(self.ctx)
            recipedct = self.load_file("recipes/recipes/" + file)
            issues += recipe.load(recipedct)
            recipe.srcpath = file
            recipe.outpath = file[:-5] + ".html"
            recipes.append(recipe)

        if len(issues) != 0:
            for issue in issues:
                print("ERROR", issue)
            return

        self.rendertemplate("index.html", "html", "index.html", {"recipes": recipes})
        for recipe in recipes:
            self.rendertemplate(
                "recipe.html", "html", recipe.outpath, {"recipe": recipe}
            )

    def finish(self) -> None:
        files = set()
        for _, _, filesx in os.walk("out/html"):
            files = set(filesx)

        # files we did not generate, probably left by a previous run, but not valid anymore
        extra_files = files - self.outfiles
        for file in extra_files:
            print(f"removing obsolete {file}")
            os.remove(f"out/html/{file}")

    def main(self) -> None:
        self.load()
        self.run()
        self.finish()


if __name__ == "__main__":
    builder = Builder()
    builder.main()