from __future__ import annotations

from datetime import date
from typing import Annotated, Any, Literal

from pydantic import BaseModel, ConfigDict, Field, RootModel, field_validator, model_validator

try:
    from openenv.core.env_server.types import Action, Observation, State
except ImportError:
    from enterprise_finance_env._compat import Action, Observation, State


class StructuredLedgerRow(BaseModel):
    model_config = ConfigDict(extra="forbid")

    txn_id: str = Field(..., min_length=3)
    entity_id: str = Field(..., min_length=2)
    counterparty_entity_id: str = Field(..., min_length=2)
    account_code: str = Field(..., min_length=2)
    side: Literal["debit", "credit"]
    amount: float = Field(..., gt=0)
    currency: str = Field(..., min_length=3, max_length=3)
    txn_date: str
    reference: str = Field(..., min_length=3)
    matched: bool = False
    eligible_for_linking: bool = True
    has_fx_adjustment: bool = False
    disputed: bool = False

    @field_validator("txn_date")
    @classmethod
    def validate_txn_date(cls, value: str) -> str:
        date.fromisoformat(value)
        return value

    @field_validator("currency")
    @classmethod
    def normalize_currency(cls, value: str) -> str:
        return value.upper()


class EnterpriseFinanceObservation(Observation):
    structured_ledgers: list[StructuredLedgerRow] = Field(default_factory=list)
    unstructured_invoices: list[dict[str, Any] | str] = Field(default_factory=list)
    fx_rates: dict[str, float] = Field(default_factory=dict)
    dispute_inbox: list[dict[str, Any] | str] = Field(default_factory=list)
    feedback_message: str = Field(default="")


class EnterpriseFinanceState(State):
    difficulty: Literal["easy", "medium", "hard"] = "easy"
    scenario_id: str = Field(default="")
    initial_abs_balance: float = Field(default=0.0, ge=0)
    open_abs_balance: float = Field(default=0.0, ge=0)
    linked_pairs: list[tuple[str, str]] = Field(default_factory=list)
    fx_adjustments: dict[str, float] = Field(default_factory=dict)
    invalid_actions: int = Field(default=0, ge=0)
    deleted_txn_ids: list[str] = Field(default_factory=list)
    expected_terminal_amount: float = Field(default=0.0)
    expected_terminal_account: str = Field(default="")
    audit_flags: list[str] = Field(default_factory=list)
    valid_event_count: int = Field(default=0, ge=0)
    unmatched_valid_count: int = Field(default=0, ge=0)
    total_reward: float = Field(default=0.0)
    final_score: float | None = Field(default=None, ge=0, le=1)
    force_balance_attempted: bool = False


class QuerySubledger(Action):
    type: Literal["query_subledger"] = "query_subledger"
    entity: str = Field(..., min_length=2)
    account_code: str = Field(..., min_length=2)
    date_range: tuple[str, str]

    @field_validator("date_range")
    @classmethod
    def validate_date_range(cls, value: tuple[str, str]) -> tuple[str, str]:
        start = date.fromisoformat(value[0])
        end = date.fromisoformat(value[1])
        if start > end:
            raise ValueError("date_range start must be on or before end")
        return value


class LinkTransactions(Action):
    type: Literal["link_transactions"] = "link_transactions"
    debit_txn_id: str = Field(..., min_length=3)
    credit_txn_id: str = Field(..., min_length=3)
    rationale: str = Field(..., min_length=5, max_length=500)


class ApplyForexAdjustment(Action):
    type: Literal["apply_forex_adjustment"] = "apply_forex_adjustment"
    txn_id: str = Field(..., min_length=3)
    exchange_rate: float = Field(..., gt=0)
    date: str

    @field_validator("date")
    @classmethod
    def validate_date(cls, value: str) -> str:
        date.fromisoformat(value)
        return value


class PostEliminationEntry(Action):
    type: Literal["post_elimination_entry"] = "post_elimination_entry"
    entity_id: str = Field(..., min_length=2)
    amount: float
    account: str = Field(..., min_length=2)


EnterpriseFinanceAction = Annotated[
    QuerySubledger | LinkTransactions | ApplyForexAdjustment | PostEliminationEntry,
    Field(discriminator="type"),
]


class EnterpriseFinanceActionPayload(RootModel[EnterpriseFinanceAction]):
    root: EnterpriseFinanceAction


ActionLike = (
    QuerySubledger
    | LinkTransactions
    | ApplyForexAdjustment
    | PostEliminationEntry
    | EnterpriseFinanceActionPayload
)


class EnterpriseFinanceStepPayload(BaseModel):
    model_config = ConfigDict(extra="forbid")

    observation: EnterpriseFinanceObservation
    reward: float | None = None
    done: bool = False


def unwrap_action(action: ActionLike) -> QuerySubledger | LinkTransactions | ApplyForexAdjustment | PostEliminationEntry:
    if isinstance(action, EnterpriseFinanceActionPayload):
        return action.root
    return action