package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"strings"
	"time"

	"git.cin.su/m/Assistant/contracts/artifact"
	"git.cin.su/m/Assistant/contracts/capability"
	"git.cin.su/m/Assistant/contracts/cognitive"
	"git.cin.su/m/Assistant/contracts/work"
	capabilitydomain "git.cin.su/m/Assistant/modules/capability/domain"
)

type bridge struct {
	cognitiveURL string
	callbackURL  string
	verifierURL  string
	client       *http.Client
}

func main() {
	b := bridge{
		cognitiveURL: strings.TrimRight(envOr("COGNITIVE_WORKER_URL", "http://cognitive-worker:8083"), "/"),
		callbackURL:  strings.TrimRight(envOr("WORK_GRAPH_RUNTIME_URL", "http://work-graph-runtime:8088"), "/"),
		verifierURL:  strings.TrimRight(envOr("TASK_VERIFIER_URL", "http://task-verifier:8091"), "/"),
		client:       &http.Client{Timeout: 10 * time.Minute},
	}
	mux := http.NewServeMux()
	mux.HandleFunc("/healthz", healthHandler)
	mux.HandleFunc("/readyz", healthHandler)
	mux.HandleFunc("/v1/execute", b.executeHandler)
	addr := envOr("LISTEN_ADDR", ":8092")
	if err := http.ListenAndServe(addr, mux); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}

func (b bridge) executeHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	var request work.AgentExecutionRequest
	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20)).Decode(&request); err != nil {
		http.Error(w, "invalid execution request", http.StatusBadRequest)
		return
	}
	result, err := b.execute(r.Context(), request)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadGateway)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(result)
}

func (b bridge) execute(ctx context.Context, request work.AgentExecutionRequest) (work.AgentExecutionResult, error) {
	now := time.Now().UnixMilli()
	intent := request.Intent
	if intent.TaskEvaluationExecution != nil && intent.TaskEvaluationExecution.GenericMessage != "" {
		return b.executeGenericCognitiveWork(ctx, request, *intent.TaskEvaluationExecution)
	}
	if intent.TaskEvaluationExecution == nil || intent.TaskEvaluationProfile == nil || len(intent.TaskEvaluationCases) == 0 {
		return work.AgentExecutionResult{State: work.AgentExecutionWaiting, Summary: "локальный bridge не поддерживает это намерение; работа сохранена и ожидает подходящего исполнителя", ObservedAtUnixMillis: now}, nil
	}
	execution := intent.TaskEvaluationExecution
	if execution.GraphID == "" || execution.NodeID == "" || execution.BindingRevision < 1 || execution.ActorID == "" || execution.PrincipalID == "" || execution.ScopeID == "" {
		return work.AgentExecutionResult{State: work.AgentExecutionWaiting, Summary: "контекст task-evaluation неполон; работа сохранена для повторной маршрутизации", ObservedAtUnixMillis: now}, nil
	}
	payload := capability.TaskEvaluationExecutionRequest{Profile: *intent.TaskEvaluationProfile, CapabilityID: intent.TaskEvaluationProfile.CapabilityID, BindingID: intent.TaskEvaluationBindingID, BindingRevision: execution.BindingRevision, ActorID: execution.ActorID, PrincipalID: execution.PrincipalID, ScopeID: execution.ScopeID, Cases: intent.TaskEvaluationCases, MaxOutputBytes: 4096}
	response, err := postJSON[capability.TaskEvaluationExecutionResponse](ctx, b.client, b.cognitiveURL+"/v1/task-evaluations/execute", payload)
	if err != nil {
		return work.AgentExecutionResult{}, err
	}
	if len(response.Responses) == 0 || response.ObservedAtUnixMillis < 1 {
		return work.AgentExecutionResult{}, fmt.Errorf("task evaluation returned no observations")
	}
	caseByID := make(map[string]capability.TaskEvaluationCase, len(intent.TaskEvaluationCases))
	for _, item := range intent.TaskEvaluationCases {
		caseByID[item.CaseID] = item
	}
	observations := response.Observations
	if !hasCriticalFailure(observations) {
		observations = make([]capability.TaskCaseObservation, 0, len(response.Responses))
		for _, item := range response.Responses {
			caseValue, ok := caseByID[item.CaseID]
			if !ok || caseValue.Verification.Mode == "" {
				return work.AgentExecutionResult{State: work.AgentExecutionWaiting, Summary: "task-evaluation case has no bounded verifier; work remains waiting", ObservedAtUnixMillis: time.Now().UnixMilli()}, nil
			}
			verified, verifyErr := postJSON[capability.TaskCaseVerificationResponse](ctx, b.client, b.verifierURL+"/v1/task-evaluations/verify", capability.TaskCaseVerificationRequest{CaseID: item.CaseID, ResponseText: item.ResponseText, LatencyMicros: item.LatencyMicros, EvidenceArtifactRef: item.EvidenceArtifactRef, Verification: caseValue.Verification})
			if verifyErr != nil {
				return work.AgentExecutionResult{}, verifyErr
			}
			observations = append(observations, capability.TaskCaseObservation{CaseID: verified.CaseID, Result: verified.Result, QualityScoreMillis: verified.QualityScoreMillis, LatencyMicros: verified.LatencyMicros, CriticalFailure: verified.CriticalFailure, EvidenceArtifactRef: verified.EvidenceArtifactRef, VerificationEvidenceRef: verified.VerificationEvidenceRef, VerifierIdentity: verified.VerifierIdentity})
		}
	}
	evaluation, err := capabilitydomain.BuildTaskEvaluation(*intent.TaskEvaluationProfile, capability.TaskEvaluationID("evaluation:"+intent.DispatchID), response.BindingID, response.BindingRevision, intent.TaskEvaluationProfile.CapabilityID, observations, artifact.ArtifactID(intent.TaskEvaluationCases[0].EvidenceArtifactRef), response.ObservedAtUnixMillis)
	if err != nil {
		return work.AgentExecutionResult{}, err
	}
	callback := work.TaskEvaluationEvidenceCallback{GraphID: execution.GraphID, Revision: execution.GraphRevision, NodeID: execution.NodeID, Evaluation: evaluation, Succeeded: true}
	if _, err := postJSON[json.RawMessage](ctx, b.client, b.callbackURL+"/v1/work-graphs/task-evaluations/callback", callback); err != nil {
		return work.AgentExecutionResult{}, err
	}
	return work.AgentExecutionResult{State: work.AgentExecutionCompleted, Summary: "local bridge executed task evaluation and persisted verifier callback", OutcomeRef: string(evaluation.ID), ArtifactRefs: []string{string(evaluation.ArtifactID)}, ObservedAtUnixMillis: time.Now().UnixMilli()}, nil
}

func (b bridge) executeGenericCognitiveWork(ctx context.Context, request work.AgentExecutionRequest, execution work.TaskEvaluationDispatchContext) (work.AgentExecutionResult, error) {
	if execution.GraphID == "" || execution.NodeID == "" || execution.ActorID == "" || execution.PrincipalID == "" || execution.ScopeID == "" {
		return work.AgentExecutionResult{State: work.AgentExecutionWaiting, Summary: "generic cognitive work context is incomplete; durable work remains waiting for rerouting", ObservedAtUnixMillis: time.Now().UnixMilli()}, nil
	}
	maxOutputBytes := execution.GenericMaxOutputBytes
	if maxOutputBytes < 1 {
		maxOutputBytes = 4096
	}
	dataPolicy := capability.DataPolicy(execution.GenericDataPolicy)
	if dataPolicy == "" {
		dataPolicy = capability.DataPolicyLocalOnly
	}
	response, err := postJSON[cognitive.GatewayAdvisoryResponse](ctx, b.client, b.cognitiveURL+"/v1/advisories", cognitive.GatewayAdvisoryRequest{
		Version: cognitive.CreatorAdvisoryV1, RequestID: cognitive.RequestID("agent-work:" + request.Intent.DispatchID), ActorID: execution.ActorID,
		PrincipalID: execution.PrincipalID, ScopeID: execution.ScopeID, Message: execution.GenericMessage, Locale: execution.GenericLocale,
		MaxOutputBytes: maxOutputBytes, DataPolicy: dataPolicy, Meaning: cognitive.TaskMeaning{SpeechAct: "DIRECTIVE", RequestedOutcome: execution.GenericPurpose},
	})
	if err != nil {
		return work.AgentExecutionResult{}, err
	}
	if response.FinishReason != cognitive.FinishCompleted || strings.TrimSpace(response.AdvisoryText) == "" {
		return work.AgentExecutionResult{}, fmt.Errorf("generic cognitive work did not complete: %s", response.FinishReason)
	}
	candidateID := "candidate:" + request.Intent.DispatchID
	artifactRef := work.EvidenceRef("agent-output:" + request.Intent.DispatchID)
	verification, err := postJSON[work.GenericCandidateVerificationResponse](ctx, b.client, b.verifierURL+"/v1/work-graphs/candidates/verify", work.GenericCandidateVerificationRequest{
		GraphID: execution.GraphID, GraphRevision: execution.GraphRevision, NodeID: execution.NodeID, AuthorRunID: request.Intent.RunID, CandidateID: candidateID, Summary: response.AdvisoryText, EvidenceRefs: []work.EvidenceRef{artifactRef},
	})
	if err != nil {
		return work.AgentExecutionResult{}, err
	}
	if !verification.Verified || verification.VerificationEvidenceRef == "" || verification.VerifierIdentity == "" {
		return work.AgentExecutionResult{State: work.AgentExecutionWaiting, Summary: "generic candidate envelope was not independently verified; work remains waiting", ObservedAtUnixMillis: time.Now().UnixMilli()}, nil
	}
	candidate := work.GraphResultCallback{GraphID: execution.GraphID, Revision: execution.GraphRevision, Candidate: work.ResultCandidate{
		ID: candidateID, GraphID: execution.GraphID, GraphRevision: execution.GraphRevision, NodeID: execution.NodeID,
		AuthorRunID: request.Intent.RunID, ArtifactRefs: []work.EvidenceRef{artifactRef, work.EvidenceRef(verification.VerificationEvidenceRef)}, EvidenceSummary: "candidate attribution and evidence envelope independently verified; semantic content remains unverified",
		Summary: response.AdvisoryText,
	}}
	if _, err := postJSON[json.RawMessage](ctx, b.client, b.callbackURL+"/v1/work-graphs/result-callback", candidate); err != nil {
		return work.AgentExecutionResult{}, err
	}
	return work.AgentExecutionResult{State: work.AgentExecutionCompleted, Summary: "local cognitive specialist produced a candidate for independent verification", OutcomeRef: "candidate:" + request.Intent.DispatchID, ArtifactRefs: []string{"agent-output:" + request.Intent.DispatchID}, ObservedAtUnixMillis: time.Now().UnixMilli()}, nil
}

func hasCriticalFailure(observations []capability.TaskCaseObservation) bool {
	for _, observation := range observations {
		if observation.CriticalFailure {
			return true
		}
	}
	return false
}

func postJSON[T any](ctx context.Context, client *http.Client, url string, payload any) (T, error) {
	var result T
	body, err := json.Marshal(payload)
	if err != nil {
		return result, err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
	if err != nil {
		return result, err
	}
	req.Header.Set("Content-Type", "application/json")
	resp, err := client.Do(req)
	if err != nil {
		return result, err
	}
	defer resp.Body.Close()
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return result, fmt.Errorf("POST %s: status %s", url, resp.Status)
	}
	if resp.StatusCode == http.StatusNoContent {
		return result, nil
	}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return result, err
	}
	return result, nil
}

func healthHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	_, _ = w.Write([]byte(`{"runtime":"agent-execution-bridge","status":"ok","capabilities":["task-evaluation","generic-cognitive-work"]}`))
}

func envOr(name, fallback string) string {
	if value := strings.TrimSpace(os.Getenv(name)); value != "" {
		return value
	}
	return fallback
}