package api

import (
	"net/http"
	"strconv"
	"time"

	"github.com/rcourtman/pulse-go-rewrite/internal/ai"
	"github.com/rcourtman/pulse-go-rewrite/internal/license"
	"github.com/rcourtman/pulse-go-rewrite/internal/utils"
	"github.com/rs/zerolog/log"
)

const aiIntelligenceUpgradeURL = "https://pulsemonitor.app/pro"

// HandleGetPatterns returns detected failure patterns (GET /api/ai/intelligence/patterns)
func (h *AISettingsHandler) HandleGetPatterns(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"patterns": []interface{}{},
			"message":  "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write patterns response")
		}
		return
	}

	detector := patrol.GetPatternDetector()
	if detector == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"patterns": []interface{}{},
			"message":  "Pattern detector not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write patterns response")
		}
		return
	}

	// Get resource filter if provided
	resourceID := r.URL.Query().Get("resource_id")

	patterns := detector.GetPatterns()
	var result []map[string]interface{}

	for key, pattern := range patterns {
		if resourceID != "" && pattern.ResourceID != resourceID {
			continue
		}
		result = append(result, map[string]interface{}{
			"key":              key,
			"resource_id":      pattern.ResourceID,
			"event_type":       pattern.EventType,
			"occurrences":      pattern.Occurrences,
			"average_interval": pattern.AverageInterval.String(),
			"average_duration": pattern.AverageDuration.String(),
			"last_occurrence":  pattern.LastOccurrence,
			"confidence":       pattern.Confidence,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"patterns":         result,
		"count":            count,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write patterns response")
	}
}

// HandleGetPredictions returns failure predictions (GET /api/ai/intelligence/predictions)
func (h *AISettingsHandler) HandleGetPredictions(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"predictions": []interface{}{},
			"message":     "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write predictions response")
		}
		return
	}

	detector := patrol.GetPatternDetector()
	if detector == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"predictions": []interface{}{},
			"message":     "Pattern detector not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write predictions response")
		}
		return
	}

	// Get resource filter if provided
	resourceID := r.URL.Query().Get("resource_id")

	var predictions []ai.FailurePrediction
	if resourceID != "" {
		predictions = detector.GetPredictionsForResource(resourceID)
	} else {
		predictions = detector.GetPredictions()
	}

	var result []map[string]interface{}
	for _, pred := range predictions {
		isOverdue := pred.DaysUntil < 0
		result = append(result, map[string]interface{}{
			"resource_id":  pred.ResourceID,
			"event_type":   pred.EventType,
			"predicted_at": pred.PredictedAt,
			"days_until":   pred.DaysUntil,
			"confidence":   pred.Confidence,
			"basis":        pred.Basis,
			"is_overdue":   isOverdue,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"predictions":      result,
		"count":            count,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write predictions response")
	}
}

// HandleGetCorrelations returns detected resource correlations (GET /api/ai/intelligence/correlations)
func (h *AISettingsHandler) HandleGetCorrelations(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"correlations": []interface{}{},
			"message":      "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write correlations response")
		}
		return
	}

	detector := patrol.GetCorrelationDetector()
	if detector == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"correlations": []interface{}{},
			"message":      "Correlation detector not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write correlations response")
		}
		return
	}

	// Get resource filter if provided
	resourceID := r.URL.Query().Get("resource_id")

	var correlations []*ai.Correlation
	if resourceID != "" {
		correlations = detector.GetCorrelationsForResource(resourceID)
	} else {
		correlations = detector.GetCorrelations()
	}

	var result []map[string]interface{}
	for _, corr := range correlations {
		result = append(result, map[string]interface{}{
			"source_id":     corr.SourceID,
			"source_name":   corr.SourceName,
			"source_type":   corr.SourceType,
			"target_id":     corr.TargetID,
			"target_name":   corr.TargetName,
			"target_type":   corr.TargetType,
			"event_pattern": corr.EventPattern,
			"occurrences":   corr.Occurrences,
			"avg_delay":     corr.AvgDelay.String(),
			"confidence":    corr.Confidence,
			"last_seen":     corr.LastSeen,
			"description":   corr.Description,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"correlations":     result,
		"count":            count,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write correlations response")
	}
}

// HandleGetRecentChanges returns recent infrastructure changes (GET /api/ai/intelligence/changes)
func (h *AISettingsHandler) HandleGetRecentChanges(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"changes": []interface{}{},
			"message": "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write changes response")
		}
		return
	}

	detector := patrol.GetChangeDetector()
	if detector == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"changes": []interface{}{},
			"message": "Change detector not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write changes response")
		}
		return
	}

	// Get time range - default to 24 hours
	hoursStr := r.URL.Query().Get("hours")
	hours := 24
	if hoursStr != "" {
		if h, err := strconv.Atoi(hoursStr); err == nil && h > 0 {
			hours = h
		}
	}

	since := time.Now().Add(-time.Duration(hours) * time.Hour)
	changes := detector.GetRecentChanges(100, since)

	var result []map[string]interface{}
	for _, change := range changes {
		result = append(result, map[string]interface{}{
			"id":            change.ID,
			"resource_id":   change.ResourceID,
			"resource_name": change.ResourceName,
			"resource_type": change.ResourceType,
			"change_type":   change.ChangeType,
			"before":        change.Before,
			"after":         change.After,
			"detected_at":   change.DetectedAt,
			"description":   change.Description,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"changes":          result,
		"count":            count,
		"hours":            hours,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write changes response")
	}
}

// HandleGetBaselines returns learned resource baselines (GET /api/ai/intelligence/baselines)
func (h *AISettingsHandler) HandleGetBaselines(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"baselines": []interface{}{},
			"message":   "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write baselines response")
		}
		return
	}

	store := patrol.GetBaselineStore()
	if store == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"baselines": []interface{}{},
			"message":   "Baseline store not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write baselines response")
		}
		return
	}

	// Get resource filter if provided
	resourceID := r.URL.Query().Get("resource_id")

	baselines := store.GetAllBaselines()
	var result []map[string]interface{}

	for key, baseline := range baselines {
		if resourceID != "" && baseline.ResourceID != resourceID {
			continue
		}
		result = append(result, map[string]interface{}{
			"key":         key,
			"resource_id": baseline.ResourceID,
			"metric":      baseline.Metric,
			"mean":        baseline.Mean,
			"std_dev":     baseline.StdDev,
			"min":         baseline.Min,
			"max":         baseline.Max,
			"samples":     baseline.Samples,
			"last_update": baseline.LastUpdate,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"baselines":        result,
		"count":            count,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write baselines response")
	}
}

// HandleGetRemediations returns remediation history (GET /api/ai/intelligence/remediations)
func (h *AISettingsHandler) HandleGetRemediations(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	patrol := h.aiService.GetPatrolService()
	if patrol == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"remediations": []interface{}{},
			"message":      "Patrol service not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write remediations response")
		}
		return
	}

	remediationLog := patrol.GetRemediationLog()
	if remediationLog == nil {
		if err := utils.WriteJSONResponse(w, map[string]interface{}{
			"remediations": []interface{}{},
			"message":      "Remediation log not initialized",
		}); err != nil {
			log.Error().Err(err).Msg("Failed to write remediations response")
		}
		return
	}

	resourceID := r.URL.Query().Get("resource_id")
	findingID := r.URL.Query().Get("finding_id")

	limit := 20
	if limitStr := r.URL.Query().Get("limit"); limitStr != "" {
		if parsed, err := strconv.Atoi(limitStr); err == nil && parsed > 0 {
			limit = parsed
		}
	}
	if limit > 100 {
		limit = 100
	}

	hours := 168
	if hoursStr := r.URL.Query().Get("hours"); hoursStr != "" {
		if parsed, err := strconv.Atoi(hoursStr); err == nil && parsed > 0 {
			hours = parsed
		}
	}
	since := time.Now().Add(-time.Duration(hours) * time.Hour)

	var records []ai.RemediationRecord
	switch {
	case findingID != "":
		records = remediationLog.GetForFinding(findingID, limit)
	case resourceID != "":
		records = remediationLog.GetForResource(resourceID, limit)
	default:
		records = remediationLog.GetRecentRemediations(limit, since)
	}

	stats := remediationStatsFromRecords(records)
	if findingID == "" && resourceID == "" {
		stats = remediationLog.GetRecentRemediationStats(since)
	}

	result := make([]map[string]interface{}, 0, len(records))
	for _, rec := range records {
		durationMs := int64(0)
		if rec.Duration > 0 {
			durationMs = rec.Duration.Milliseconds()
		}
		result = append(result, map[string]interface{}{
			"id":            rec.ID,
			"timestamp":     rec.Timestamp,
			"resource_id":   rec.ResourceID,
			"resource_type": rec.ResourceType,
			"resource_name": rec.ResourceName,
			"finding_id":    rec.FindingID,
			"problem":       rec.Problem,
			"action":        rec.Action,
			"output":        rec.Output,
			"outcome":       rec.Outcome,
			"duration_ms":   durationMs,
			"note":          rec.Note,
			"automatic":     rec.Automatic,
		})
	}

	locked := !h.aiService.HasLicenseFeature(license.FeatureAIPatrol)
	if locked {
		w.Header().Set("X-License-Required", "true")
		w.Header().Set("X-License-Feature", license.FeatureAIPatrol)
	}

	count := len(result)
	if locked {
		result = []map[string]interface{}{}
	}

	if err := utils.WriteJSONResponse(w, map[string]interface{}{
		"remediations":     result,
		"count":            count,
		"stats":            stats,
		"license_required": locked,
		"upgrade_url":      aiIntelligenceUpgradeURL,
	}); err != nil {
		log.Error().Err(err).Msg("Failed to write remediations response")
	}
}

func remediationStatsFromRecords(records []ai.RemediationRecord) map[string]int {
	stats := map[string]int{
		"total":     len(records),
		"resolved":  0,
		"partial":   0,
		"failed":    0,
		"unknown":   0,
		"automatic": 0,
		"manual":    0,
	}

	for _, rec := range records {
		switch rec.Outcome {
		case ai.OutcomeResolved:
			stats["resolved"]++
		case ai.OutcomePartial:
			stats["partial"]++
		case ai.OutcomeFailed:
			stats["failed"]++
		default:
			stats["unknown"]++
		}
		if rec.Automatic {
			stats["automatic"]++
		} else {
			stats["manual"]++
		}
	}

	return stats
}