"""
Email Triage & Response Environment
OpenEnv-compatible environment for agent evaluation.
"""

import json
from typing import Optional, Literal
from pydantic import BaseModel, Field

class Email(BaseModel):
    id: str
    from_: str = Field(..., alias="from")
    subject: str
    body: str
    labels: list[str] = []
    replied: bool = False
    archived: bool = False
    flagged: bool = False
    flag_reason: Optional[str] = None
    reply_body: Optional[str] = None

    class Config:
        populate_by_name = True


class InboxState(BaseModel):
    inbox: list[Email]
    sent: list[dict] = []
    step_count: int = 0


class Observation(BaseModel):
    status: str
    message: str
    data: Optional[dict] = None
    step_count: int = 0


class Action(BaseModel):
    action: Literal["label", "draft_reply", "archive", "flag", "read", "list_inbox"]
    email_id: Optional[str] = None
    priority: Optional[Literal["urgent", "normal", "low"]] = None
    body: Optional[str] = None
    reason: Optional[str] = None


class StepResult(BaseModel):
    observation: Observation
    reward: float
    done: bool
    info: dict = {}

import os

# Load dataset (generated by curate_dataset.py)
DATASET_PATH = os.path.join(os.path.dirname(__file__), "data", "emails.json")
try:
    with open(DATASET_PATH, "r", encoding="utf-8") as f:
        _dataset = json.load(f)
except FileNotFoundError:
    # Fallback to empty if not curated yet, though curate_dataset.py should be run first
    _dataset = {"task1": {"emails": [], "ground_truth": {}}, "task2": {"emails": []}, "task3": {"emails": [], "ground_truth": {}, "urgent_ids": [], "archive_ids": [], "flag_ids": []}}

TASK1_EMAILS = _dataset["task1"]["emails"]
TASK1_GROUND_TRUTH = _dataset["task1"].get("ground_truth", {})

TASK2_EMAIL = _dataset["task2"]["emails"][0] if _dataset["task2"]["emails"] else {}

TASK3_EMAILS = _dataset["task3"]["emails"]
TASK3_GROUND_TRUTH = _dataset["task3"].get("ground_truth", {})

TASK3_URGENT_IDS = set(_dataset["task3"].get("urgent_ids", []))
TASK3_ARCHIVE_IDS = set(_dataset["task3"].get("archive_ids", []))
TASK3_FLAG_IDS    = set(_dataset["task3"].get("flag_ids", []))

def grade_task1(state: InboxState) -> float:
    score = 0.0
    for email in state.inbox:
        gt = TASK1_GROUND_TRUTH.get(email.id)
        if gt and "urgent" in email.labels and gt == "urgent":
            score += 0.2
        elif gt and "normal" in email.labels and gt == "normal":
            score += 0.2
        elif gt and "low" in email.labels and gt == "low":
            score += 0.2
    return round(min(score, 1.0), 2)


def grade_task2(state: InboxState) -> float:
    score = 0.0
    email = next((e for e in state.inbox if e.id == "t2_001"), None)
    if email is None or not email.replied or not email.reply_body:
        return 0.0

    reply = email.reply_body.lower()

    issues_covered = 0
    if "order" in reply and ("48291" in reply or "order" in reply):
        issues_covered += 1
    if any(w in reply for w in ["refund", "deliver", "shipment", "track"]):
        issues_covered += 1
    if any(w in reply for w in ["compensat", "apologi", "sorry", "inconvenien"]):
        issues_covered += 1
    score += 0.1 * issues_covered  # up to 0.3

    # +0.3 professional tone
    professional_signals = ["dear", "sincerely", "regards", "thank you", "we apologize",
                            "we understand", "please", "we will"]
    rude_signals = ["whatever", "not our fault", "calm down"]
    tone_score = sum(1 for w in professional_signals if w in reply)
    rude_penalty = sum(1 for w in rude_signals if w in reply)
    score += min(0.3, tone_score * 0.05) - (rude_penalty * 0.1)

    # +0.2 correct recipient / subject handling
    if email.reply_body and len(email.reply_body) > 50:
        score += 0.2

    # +0.2 no fabricated facts (heuristic: no invented order dates / amounts)
    fabrication_signals = ["$", "€", "refund amount", "exact date", "tracking number is"]
    fab_hits = sum(1 for w in fabrication_signals if w in reply)
    if fab_hits == 0:
        score += 0.2

    return round(max(0.0, min(score, 1.0)), 2)


def grade_task3(state: InboxState, penalties: dict) -> float:
    score = 0.0
    email_map = {e.id: e for e in state.inbox}

    # Priority labels (0.2 per correct, 10 emails = max 2.0 → normalise to 0.5 weight)
    label_score = 0.0
    for eid, gt in TASK3_GROUND_TRUTH.items():
        email = email_map.get(eid)
        if email and gt in email.labels:
            label_score += 0.2
    score += min(label_score, 2.0) * 0.25   # normalise to 0.5

    # Replies for urgent emails (max 0.4)
    reply_scores = []
    for eid in TASK3_URGENT_IDS:
        email = email_map.get(eid)
        if email and email.replied and email.reply_body:
            reply_scores.append(min(len(email.reply_body) / 200, 1.0) * 0.1)
    score += sum(reply_scores)

    # Archive spam (0.05 each, max 0.1)
    for eid in TASK3_ARCHIVE_IDS:
        email = email_map.get(eid)
        if email and email.archived:
            score += 0.05

    # Flag ambiguous (0.05 each)
    for eid in TASK3_FLAG_IDS:
        email = email_map.get(eid)
        if email and email.flagged:
            score += 0.05

    # Penalties
    score -= penalties.get("destructive_actions", 0) * 0.1
    score -= penalties.get("loop_actions", 0) * 0.05

    return round(max(0.0, min(score, 1.0)), 2)


# ---------------------------------------------------------------------------
# Environment Class
# ---------------------------------------------------------------------------

class EmailTriageEnv:
    """OpenEnv-compatible Email Triage environment."""

    TASKS = {1, 2, 3}

    def __init__(self, task: int = 1):
        assert task in self.TASKS, f"task must be one of {self.TASKS}"
        self.task = task
        self._state: Optional[InboxState] = None
        self._penalties = {"destructive_actions": 0, "loop_actions": 0}
        self._action_history: list[str] = []
        self._done = False

    # ------------------------------------------------------------------
    # OpenEnv interface
    # ------------------------------------------------------------------

    def reset(self) -> Observation:
        self._penalties = {"destructive_actions": 0, "loop_actions": 0}
        self._action_history = []
        self._done = False

        if self.task == 1:
            emails = [Email.model_validate(e) for e in TASK1_EMAILS]
        elif self.task == 2:
            emails = [Email.model_validate(TASK2_EMAIL)]
        else:
            emails = [Email.model_validate(e) for e in TASK3_EMAILS]

        self._state = InboxState(inbox=emails)

        return Observation(
            status="ok",
            message=f"Task {self.task} environment reset. Inbox contains {len(emails)} email(s).",
            data={"task": self.task, "inbox_size": len(emails)},
            step_count=0,
        )

    def state(self) -> dict:
        assert self._state is not None, "Call reset() first."
        return json.loads(self._state.model_dump_json(by_alias=True))

    def step(self, action: Action) -> StepResult:
        assert self._state is not None, "Call reset() first."

        if self._done:
            return StepResult(
                observation=Observation(status="done", message="Episode already finished.", step_count=self._state.step_count),
                reward=0.0,
                done=True,
            )

        self._state.step_count += 1
        action_key = f"{action.action}:{action.email_id}"

        # Loop detection
        if self._action_history.count(action_key) >= 2:
            self._penalties["loop_actions"] += 1

        self._action_history.append(action_key)
        obs, reward = self._dispatch(action)
        obs.step_count = self._state.step_count
        return StepResult(observation=obs, reward=reward, done=self._done)

    def score(self) -> float:
        """Return current cumulative score (0-1)."""
        assert self._state is not None, "Call reset() first."
        if self.task == 1:
            return grade_task1(self._state)
        elif self.task == 2:
            return grade_task2(self._state)
        else:
            return grade_task3(self._state, self._penalties)

    # ------------------------------------------------------------------
    # Action dispatch
    # ------------------------------------------------------------------

    def _dispatch(self, action: Action):
        handlers = {
            "list_inbox": self._act_list_inbox,
            "read":       self._act_read,
            "label":      self._act_label,
            "draft_reply":self._act_draft_reply,
            "archive":    self._act_archive,
            "flag":       self._act_flag,
        }
        handler = handlers.get(action.action)
        if handler is None:
            return Observation(status="error", message=f"Unknown action: {action.action}"), 0.0
        return handler(action)

    def _act_list_inbox(self, action: Action):
        summaries = [
            {"id": e.id, "from": e.from_, "subject": e.subject,
             "labels": e.labels, "replied": e.replied, "archived": e.archived, "flagged": e.flagged}
            for e in self._state.inbox
        ]
        return Observation(status="ok", message="Inbox listed.", data={"emails": summaries}), 0.0

    def _act_read(self, action: Action):
        email = self._find(action.email_id)
        if email is None:
            return Observation(status="error", message=f"Email {action.email_id} not found."), 0.0
        return Observation(
            status="ok",
            message=f"Read email {action.email_id}.",
            data=json.loads(email.model_dump_json(by_alias=True)),
        ), 0.0

    def _act_label(self, action: Action):
        email = self._find(action.email_id)
        if email is None:
            return Observation(status="error", message=f"Email {action.email_id} not found."), 0.0
        if action.priority not in ("urgent", "normal", "low"):
            return Observation(status="error", message="priority must be urgent | normal | low"), 0.0

        # Remove existing priority labels then add new
        email.labels = [l for l in email.labels if l not in ("urgent", "normal", "low")]
        email.labels.append(action.priority)

        incremental = self._incremental_label_reward(email.id, action.priority)
        return Observation(
            status="ok",
            message=f"Labelled {action.email_id} as {action.priority}.",
            data={"email_id": action.email_id, "priority": action.priority},
        ), incremental

    def _act_draft_reply(self, action: Action):
        email = self._find(action.email_id)
        if email is None:
            return Observation(status="error", message=f"Email {action.email_id} not found."), 0.0
        if not action.body or len(action.body.strip()) < 10:
            return Observation(status="error", message="Reply body too short."), 0.0

        email.replied = True
        email.reply_body = action.body
        self._state.sent.append({"to": email.from_, "subject": f"Re: {email.subject}", "body": action.body})
        return Observation(status="ok", message=f"Reply drafted for {action.email_id}."), 0.0

    def _act_archive(self, action: Action):
        email = self._find(action.email_id)
        if email is None:
            return Observation(status="error", message=f"Email {action.email_id} not found."), 0.0

        # Penalty if archiving urgent email
        if "urgent" in email.labels:
            self._penalties["destructive_actions"] += 1
            return Observation(
                status="warning",
                message=f"Archived urgent email {action.email_id} — penalty applied.",
            ), -0.1

        email.archived = True
        return Observation(status="ok", message=f"Email {action.email_id} archived."), 0.0

    def _act_flag(self, action: Action):
        email = self._find(action.email_id)
        if email is None:
            return Observation(status="error", message=f"Email {action.email_id} not found."), 0.0
        email.flagged = True
        email.flag_reason = action.reason or "unspecified"
        return Observation(status="ok", message=f"Email {action.email_id} flagged for human review."), 0.0

    # ------------------------------------------------------------------
    # Helpers
    # ------------------------------------------------------------------

    def _find(self, email_id: Optional[str]) -> Optional[Email]:
        if email_id is None:
            return None
        return next((e for e in self._state.inbox if e.id == email_id), None)

    def _incremental_label_reward(self, email_id: str, priority: str) -> float:
        """Return +0.2 if label matches ground truth for task 1."""
        if self.task == 1:
            gt = TASK1_GROUND_TRUTH.get(email_id)
            return 0.2 if gt == priority else 0.0
        return 0.0