// Copyright 2026 MarketAlly. All rights reserved.
// SPDX-License-Identifier: MIT

package ai

import (
	"context"
	"errors"
	"fmt"
	"strconv"
	"strings"
	"time"

	ai_model "code.gitcaddy.com/server/v3/models/ai"
	issues_model "code.gitcaddy.com/server/v3/models/issues"
	repo_model "code.gitcaddy.com/server/v3/models/repo"
	"code.gitcaddy.com/server/v3/models/unit"
	user_model "code.gitcaddy.com/server/v3/models/user"
	"code.gitcaddy.com/server/v3/modules/ai"
	"code.gitcaddy.com/server/v3/modules/log"
	"code.gitcaddy.com/server/v3/modules/setting"
	issue_service "code.gitcaddy.com/server/v3/services/issue"
)

// OperationRequest represents a queued AI operation
type OperationRequest struct {
	RepoID        int64  `json:"repo_id"`
	Operation     string `json:"operation"`       // "code-review", "issue-response", "issue-triage", "workflow-inspect", "agent-fix"
	Tier          int    `json:"tier"`            // 1 or 2
	TriggerEvent  string `json:"trigger_event"`   // e.g. "issue.created"
	TriggerUserID int64  `json:"trigger_user_id"` // who triggered the event
	TargetID      int64  `json:"target_id"`       // issue/PR ID
	TargetType    string `json:"target_type"`     // "issue", "pull"
}

// EnqueueOperation adds an AI operation to the processing queue
func EnqueueOperation(req *OperationRequest) error {
	if aiOperationQueue == nil {
		return errors.New("AI operation queue not initialized")
	}
	return aiOperationQueue.Push(req)
}

// handleAIOperation is the queue worker that processes AI operations
func handleAIOperation(items ...*OperationRequest) []*OperationRequest {
	for _, req := range items {
		if err := processOperation(context.Background(), req); err != nil {
			log.Error("AI operation failed [repo:%d op:%s target:%d]: %v", req.RepoID, req.Operation, req.TargetID, err)
		}
	}
	return nil
}

func processOperation(ctx context.Context, req *OperationRequest) error {
	// Load repo
	repo, err := repo_model.GetRepositoryByID(ctx, req.RepoID)
	if err != nil {
		return fmt.Errorf("failed to load repo %d: %w", req.RepoID, err)
	}

	if err := repo.LoadOwner(ctx); err != nil {
		return fmt.Errorf("failed to load repo owner: %w", err)
	}

	// Rate limit check
	count, err := ai_model.CountRecentOperations(ctx, req.RepoID)
	if err != nil {
		return fmt.Errorf("failed to count recent operations: %w", err)
	}
	maxOps := setting.AI.MaxOperationsPerHour
	if repo.Owner.IsOrganization() {
		if orgSettings, err := ai_model.GetOrgAISettings(ctx, repo.OwnerID); err == nil && orgSettings != nil && orgSettings.MaxOpsPerHour > 0 {
			maxOps = orgSettings.MaxOpsPerHour
		}
	}
	if count >= int64(maxOps) {
		log.Warn("AI rate limit exceeded for repo %d (%d/%d ops/hour)", req.RepoID, count, maxOps)
		return nil
	}

	// Create operation log entry
	opLog := &ai_model.OperationLog{
		RepoID:        req.RepoID,
		Operation:     req.Operation,
		Tier:          req.Tier,
		TriggerEvent:  req.TriggerEvent,
		TriggerUserID: req.TriggerUserID,
		TargetID:      req.TargetID,
		TargetType:    req.TargetType,
		Status:        ai_model.OperationStatusPending,
	}

	// Resolve provider config from cascade
	var orgID int64
	if repo.Owner.IsOrganization() {
		orgID = repo.OwnerID
	}

	aiUnit, err := repo.GetUnit(ctx, unit.TypeAI)
	var aiCfg *repo_model.AIConfig
	if err == nil {
		aiCfg = aiUnit.AIConfig()
	} else {
		aiCfg = &repo_model.AIConfig{}
	}

	opLog.Provider = ai_model.ResolveProvider(ctx, orgID, aiCfg.PreferredProvider)
	opLog.Model = ai_model.ResolveModel(ctx, orgID, aiCfg.PreferredModel)

	// Build per-request provider config from the cascade
	providerCfg := &ai.ProviderConfig{
		Provider: opLog.Provider,
		Model:    opLog.Model,
		APIKey:   ai_model.ResolveAPIKey(ctx, orgID, opLog.Provider),
	}

	if err := ai_model.InsertOperationLog(ctx, opLog); err != nil {
		return fmt.Errorf("failed to insert operation log: %w", err)
	}

	start := time.Now()

	// Dispatch based on operation type
	var opErr error
	switch req.Operation {
	case "issue-response":
		opErr = handleIssueResponse(ctx, repo, aiCfg, opLog, providerCfg)
	case "issue-triage":
		opErr = handleIssueTriage(ctx, repo, opLog, providerCfg)
	case "code-review":
		opErr = handleCodeReview(ctx, repo, opLog, providerCfg)
	case "workflow-inspect":
		opErr = handleWorkflowInspect(ctx, repo, opLog, providerCfg)
	case "agent-fix":
		opErr = handleAgentFix(ctx, repo, aiCfg, opLog)
	default:
		opErr = fmt.Errorf("unknown operation: %s", req.Operation)
	}

	opLog.DurationMs = time.Since(start).Milliseconds()

	if opErr != nil {
		opLog.Status = ai_model.OperationStatusFailed
		opLog.ErrorMessage = opErr.Error()
		log.Error("AI operation %s failed for repo %d: %v", req.Operation, req.RepoID, opErr)

		// Escalate on failure if configured
		if aiCfg.EscalateToStaff {
			escalateToStaff(ctx, repo, aiCfg, opLog)
		}
	} else {
		opLog.Status = ai_model.OperationStatusSuccess
	}

	if err := ai_model.UpdateOperationLog(ctx, opLog); err != nil {
		log.Error("Failed to update operation log: %v", err)
	}

	return opErr
}

func handleIssueResponse(ctx context.Context, repo *repo_model.Repository, aiCfg *repo_model.AIConfig, opLog *ai_model.OperationLog, providerCfg *ai.ProviderConfig) error {
	issue, err := issues_model.GetIssueByID(ctx, opLog.TargetID)
	if err != nil {
		return fmt.Errorf("failed to load issue %d: %w", opLog.TargetID, err)
	}
	issue.Repo = repo

	client := ai.GetClient()
	resp, err := client.GenerateIssueResponse(ctx, &ai.GenerateIssueResponseRequest{
		ProviderConfig:     providerCfg,
		RepoID:             repo.ID,
		IssueID:            issue.ID,
		Title:              issue.Title,
		Body:               issue.Content,
		CustomInstructions: aiCfg.IssueInstructions,
	})
	if err != nil {
		return fmt.Errorf("AI GenerateIssueResponse failed: %w", err)
	}

	opLog.InputTokens = resp.InputTokens
	opLog.OutputTokens = resp.OutputTokens

	// Post the response as a comment from the AI bot user
	botUser := user_model.NewAIUser()
	comment, err := issue_service.CreateIssueComment(ctx, botUser, repo, issue, resp.Response, nil)
	if err != nil {
		return fmt.Errorf("failed to create comment: %w", err)
	}

	opLog.ResultCommentID = comment.ID
	return nil
}

func handleIssueTriage(ctx context.Context, repo *repo_model.Repository, opLog *ai_model.OperationLog, providerCfg *ai.ProviderConfig) error {
	issue, err := issues_model.GetIssueByID(ctx, opLog.TargetID)
	if err != nil {
		return fmt.Errorf("failed to load issue %d: %w", opLog.TargetID, err)
	}
	issue.Repo = repo

	triageResp, err := TriageIssue(ctx, issue, providerCfg)
	if err != nil {
		return fmt.Errorf("AI TriageIssue failed: %w", err)
	}

	// Apply suggested labels
	botUser := user_model.NewAIUser()
	for _, labelName := range triageResp.SuggestedLabels {
		label, err := issues_model.GetLabelInRepoByName(ctx, repo.ID, labelName)
		if err != nil {
			log.Warn("AI suggested label %q not found in repo %d", labelName, repo.ID)
			continue
		}
		if err := issue_service.AddLabel(ctx, issue, botUser, label); err != nil {
			log.Error("Failed to add label %q to issue %d: %v", labelName, issue.Index, err)
		}
	}

	return nil
}

func handleCodeReview(ctx context.Context, repo *repo_model.Repository, opLog *ai_model.OperationLog, providerCfg *ai.ProviderConfig) error {
	issue, err := issues_model.GetIssueByID(ctx, opLog.TargetID)
	if err != nil {
		return fmt.Errorf("failed to load issue %d: %w", opLog.TargetID, err)
	}
	if err := issue.LoadPullRequest(ctx); err != nil {
		return fmt.Errorf("failed to load pull request: %w", err)
	}
	issue.Repo = repo

	reviewResp, err := ReviewPullRequest(ctx, issue.PullRequest, providerCfg)
	if err != nil {
		return fmt.Errorf("AI ReviewPullRequest failed: %w", err)
	}

	// Post the review summary as a comment
	botUser := user_model.NewAIUser()
	comment, err := issue_service.CreateIssueComment(ctx, botUser, repo, issue, reviewResp.Summary, nil)
	if err != nil {
		return fmt.Errorf("failed to create review comment: %w", err)
	}

	opLog.ResultCommentID = comment.ID
	return nil
}

func handleAgentFix(ctx context.Context, repo *repo_model.Repository, aiCfg *repo_model.AIConfig, opLog *ai_model.OperationLog) error {
	// Tier 2: Trigger an Actions workflow for Claude Code headless
	runID, err := triggerAgentWorkflow(ctx, repo, aiCfg, opLog)
	if err != nil {
		return fmt.Errorf("failed to trigger agent workflow: %w", err)
	}

	opLog.ActionRunID = runID
	return nil
}

func handleWorkflowInspect(ctx context.Context, repo *repo_model.Repository, opLog *ai_model.OperationLog, providerCfg *ai.ProviderConfig) error {
	// TargetID is used to store context; for workflow inspect the file path is stored in ErrorMessage temporarily
	// We use the operation's ErrorMessage field pre-populated with the file path before dispatch
	filePath := opLog.ErrorMessage
	opLog.ErrorMessage = "" // Clear it before actual use

	resp, err := InspectWorkflow(ctx, repo, filePath, "", providerCfg)
	if err != nil {
		return fmt.Errorf("AI InspectWorkflow failed: %w", err)
	}

	opLog.InputTokens = resp.InputTokens
	opLog.OutputTokens = resp.OutputTokens

	// If there are issues, post a summary comment (for push-triggered inspections)
	if len(resp.Issues) > 0 || len(resp.Suggestions) > 0 {
		var body strings.Builder
		body.WriteString("## Workflow Inspection Results\n\n")
		body.WriteString("**File:** `" + filePath + "`\n\n")

		if !resp.Valid {
			body.WriteString("**Status:** Issues found\n\n")
		}

		for _, issue := range resp.Issues {
			icon := "ℹ️"
			switch issue.Severity {
			case "error":
				icon = "❌"
			case "warning":
				icon = "⚠️"
			}
			body.WriteString(icon + " ")
			if issue.Line > 0 {
				body.WriteString("**Line " + strconv.Itoa(issue.Line) + ":** ")
			}
			body.WriteString(issue.Message + "\n")
			if issue.Fix != "" {
				body.WriteString("  - **Fix:** " + issue.Fix + "\n")
			}
		}

		if len(resp.Suggestions) > 0 {
			body.WriteString("\n### Suggestions\n")
			for _, s := range resp.Suggestions {
				body.WriteString("- " + s + "\n")
			}
		}

		log.Info("Workflow inspection for %s in repo %d: %d issues, %d suggestions",
			filePath, repo.ID, len(resp.Issues), len(resp.Suggestions))
		// Note: for push-triggered inspections, the comment would be posted as a repo event
		// or as part of the commit status. The body is logged for now.
		_ = body.String()
	}

	return nil
}