from __future__ import annotations

from collections import defaultdict
from app.schemas import AgentResult, MergedEvent


def merge_overlapping_results(results: list[AgentResult], iou_gap: float = 2.0) -> list[MergedEvent]:
    grouped = defaultdict(list)

    for result in results:
        for finding in result.findings:
            grouped[finding.warning_type].append((result.agent_name, finding))

    merged: list[MergedEvent] = []

    for warning_type, items in grouped.items():
        items.sort(key=lambda x: x[1].start_sec)

        current = None

        for agent_name, f in items:
            if current is None:
                current = {
                    "warning_type": warning_type,
                    "start_sec": f.start_sec,
                    "end_sec": f.end_sec,
                    "confidence_sum": f.confidence,
                    "count": 1,
                    "evidences": [f.evidence],
                    "sources": [agent_name],
                    "behavior_tags": set(f.behavior_tags),
                    "clinical_note": f.clinical_note or "",
                }
                continue

            overlap = f.start_sec <= current["end_sec"] + iou_gap
            if overlap:
                current["end_sec"] = max(current["end_sec"], f.end_sec)
                current["confidence_sum"] += f.confidence
                current["count"] += 1
                current["evidences"].append(f.evidence)
                current["sources"].append(agent_name)
                current["behavior_tags"].update(f.behavior_tags)
                if len(f.clinical_note) > len(current["clinical_note"]):
                    current["clinical_note"] = f.clinical_note
            else:
                merged.append(
                    MergedEvent(
                        warning_type=current["warning_type"],
                        start_sec=current["start_sec"],
                        end_sec=current["end_sec"],
                        confidence=min(1.0, current["confidence_sum"] / current["count"]),
                        evidences=current["evidences"],
                        sources=current["sources"],
                        behavior_tags=sorted(current["behavior_tags"]),
                        clinical_note=current["clinical_note"],
                    )
                )
                current = {
                    "warning_type": warning_type,
                    "start_sec": f.start_sec,
                    "end_sec": f.end_sec,
                    "confidence_sum": f.confidence,
                    "count": 1,
                    "evidences": [f.evidence],
                    "sources": [agent_name],
                    "behavior_tags": set(f.behavior_tags),
                    "clinical_note": f.clinical_note or "",
                }

        if current is not None:
            merged.append(
                MergedEvent(
                    warning_type=current["warning_type"],
                    start_sec=current["start_sec"],
                    end_sec=current["end_sec"],
                    confidence=min(1.0, current["confidence_sum"] / current["count"]),
                    evidences=current["evidences"],
                    sources=current["sources"],
                    behavior_tags=sorted(current["behavior_tags"]),
                    clinical_note=current["clinical_note"],
                )
            )

    merged.sort(key=lambda x: (x.start_sec, x.warning_type))
    return merged