package main

import (
	"encoding/json"
	"fmt"
	"os"

	"github.com/spf13/cobra"
	"github.com/steveyegge/beads/internal/hooks"
	"github.com/steveyegge/beads/internal/rpc"
	"github.com/steveyegge/beads/internal/types"
	"github.com/steveyegge/beads/internal/ui"
	"github.com/steveyegge/beads/internal/utils"
	"github.com/steveyegge/beads/internal/validation"
)

var updateCmd = &cobra.Command{
	Use:     "update [id...]",
	GroupID: "issues",
	Short:   "Update one or more issues",
	Long: `Update one or more issues.

If no issue ID is provided, updates the last touched issue (from most recent
create, update, show, or close operation).`,
	Args: cobra.MinimumNArgs(0),
	Run: func(cmd *cobra.Command, args []string) {
		CheckReadonly("update")

		// If no IDs provided, use last touched issue
		if len(args) == 0 {
			lastTouched := GetLastTouchedID()
			if lastTouched == "" {
				FatalErrorRespectJSON("no issue ID provided and no last touched issue")
			}
			args = []string{lastTouched}
		}

		updates := make(map[string]interface{})

		if cmd.Flags().Changed("status") {
			status, _ := cmd.Flags().GetString("status")
			updates["status"] = status

			// If status is being set to closed, include session if provided
			if status == "closed" {
				session, _ := cmd.Flags().GetString("session")
				if session == "" {
					session = os.Getenv("CLAUDE_SESSION_ID")
				}
				if session != "" {
					updates["closed_by_session"] = session
				}
			}
		}
		if cmd.Flags().Changed("priority") {
			priorityStr, _ := cmd.Flags().GetString("priority")
			priority, err := validation.ValidatePriority(priorityStr)
			if err != nil {
				FatalErrorRespectJSON("%v", err)
			}
			updates["priority"] = priority
		}
		if cmd.Flags().Changed("title") {
			title, _ := cmd.Flags().GetString("title")
			updates["title"] = title
		}
		if cmd.Flags().Changed("assignee") {
			assignee, _ := cmd.Flags().GetString("assignee")
			updates["assignee"] = assignee
		}
		description, descChanged := getDescriptionFlag(cmd)
		if descChanged {
			updates["description"] = description
		}
		if cmd.Flags().Changed("design") {
			design, _ := cmd.Flags().GetString("design")
			updates["design"] = design
		}
		if cmd.Flags().Changed("notes") {
			notes, _ := cmd.Flags().GetString("notes")
			updates["notes"] = notes
		}
		if cmd.Flags().Changed("acceptance") || cmd.Flags().Changed("acceptance-criteria") {
			var acceptanceCriteria string
			if cmd.Flags().Changed("acceptance") {
				acceptanceCriteria, _ = cmd.Flags().GetString("acceptance")
			} else {
				acceptanceCriteria, _ = cmd.Flags().GetString("acceptance-criteria")
			}
			updates["acceptance_criteria"] = acceptanceCriteria
		}
		if cmd.Flags().Changed("external-ref") {
			externalRef, _ := cmd.Flags().GetString("external-ref")
			updates["external_ref"] = externalRef
		}
		if cmd.Flags().Changed("estimate") {
			estimate, _ := cmd.Flags().GetInt("estimate")
			if estimate < 0 {
				FatalErrorRespectJSON("estimate must be a non-negative number of minutes")
			}
			updates["estimated_minutes"] = estimate
		}
		if cmd.Flags().Changed("type") {
			issueType, _ := cmd.Flags().GetString("type")
			// Validate issue type
			if !types.IssueType(issueType).IsValid() {
				FatalErrorRespectJSON("invalid issue type %q. Valid types: bug, feature, task, epic, chore, merge-request, molecule, gate", issueType)
			}
			updates["issue_type"] = issueType
		}
		if cmd.Flags().Changed("add-label") {
			addLabels, _ := cmd.Flags().GetStringSlice("add-label")
			updates["add_labels"] = addLabels
		}
		if cmd.Flags().Changed("remove-label") {
			removeLabels, _ := cmd.Flags().GetStringSlice("remove-label")
			updates["remove_labels"] = removeLabels
		}
		if cmd.Flags().Changed("set-labels") {
			setLabels, _ := cmd.Flags().GetStringSlice("set-labels")
			updates["set_labels"] = setLabels
		}
		if cmd.Flags().Changed("parent") {
			parent, _ := cmd.Flags().GetString("parent")
			updates["parent"] = parent
		}
		if cmd.Flags().Changed("type") {
			issueType, _ := cmd.Flags().GetString("type")
			// Validate issue type
			if _, err := validation.ParseIssueType(issueType); err != nil {
				FatalErrorRespectJSON("%v", err)
			}
			updates["issue_type"] = issueType
		}

		// Get claim flag
		claimFlag, _ := cmd.Flags().GetBool("claim")

		if len(updates) == 0 && !claimFlag {
			fmt.Println("No updates specified")
			return
		}

		ctx := rootCtx

		// Resolve partial IDs first
		var resolvedIDs []string
		if daemonClient != nil {
			for _, id := range args {
				resolveArgs := &rpc.ResolveIDArgs{ID: id}
				resp, err := daemonClient.ResolveID(resolveArgs)
				if err != nil {
					FatalErrorRespectJSON("resolving ID %s: %v", id, err)
				}
				var resolvedID string
				if err := json.Unmarshal(resp.Data, &resolvedID); err != nil {
					FatalErrorRespectJSON("unmarshaling resolved ID: %v", err)
				}
				resolvedIDs = append(resolvedIDs, resolvedID)
			}
		} else {
			var err error
			resolvedIDs, err = utils.ResolvePartialIDs(ctx, store, args)
			if err != nil {
				FatalErrorRespectJSON("%v", err)
			}
		}

		// If daemon is running, use RPC
		if daemonClient != nil {
			updatedIssues := []*types.Issue{}
			var firstUpdatedID string // Track first successful update for last-touched
			for _, id := range resolvedIDs {
				updateArgs := &rpc.UpdateArgs{ID: id}

				// Map updates to RPC args
				if status, ok := updates["status"].(string); ok {
					updateArgs.Status = &status
				}
				if priority, ok := updates["priority"].(int); ok {
					updateArgs.Priority = &priority
				}
				if title, ok := updates["title"].(string); ok {
					updateArgs.Title = &title
				}
				if assignee, ok := updates["assignee"].(string); ok {
					updateArgs.Assignee = &assignee
				}
				if description, ok := updates["description"].(string); ok {
					updateArgs.Description = &description
				}
				if design, ok := updates["design"].(string); ok {
					updateArgs.Design = &design
				}
				if notes, ok := updates["notes"].(string); ok {
					updateArgs.Notes = &notes
				}
				if acceptanceCriteria, ok := updates["acceptance_criteria"].(string); ok {
					updateArgs.AcceptanceCriteria = &acceptanceCriteria
				}
				if externalRef, ok := updates["external_ref"].(string); ok {
					updateArgs.ExternalRef = &externalRef
				}
				if estimate, ok := updates["estimated_minutes"].(int); ok {
					updateArgs.EstimatedMinutes = &estimate
				}
				if issueType, ok := updates["issue_type"].(string); ok {
					updateArgs.IssueType = &issueType
				}
				if addLabels, ok := updates["add_labels"].([]string); ok {
					updateArgs.AddLabels = addLabels
				}
				if removeLabels, ok := updates["remove_labels"].([]string); ok {
					updateArgs.RemoveLabels = removeLabels
				}
				if setLabels, ok := updates["set_labels"].([]string); ok {
					updateArgs.SetLabels = setLabels
				}
				if issueType, ok := updates["issue_type"].(string); ok {
					updateArgs.IssueType = &issueType
				}
				if parent, ok := updates["parent"].(string); ok {
					updateArgs.Parent = &parent
				}

				// Set claim flag for atomic claim operation
				updateArgs.Claim = claimFlag

				resp, err := daemonClient.Update(updateArgs)
				if err != nil {
					fmt.Fprintf(os.Stderr, "Error updating %s: %v\n", id, err)
					continue
				}

				var issue types.Issue
				if err := json.Unmarshal(resp.Data, &issue); err == nil {
					// Run update hook
					if hookRunner != nil {
						hookRunner.Run(hooks.EventUpdate, &issue)
					}
					if jsonOutput {
						updatedIssues = append(updatedIssues, &issue)
					}
				}
				if !jsonOutput {
					fmt.Printf("%s Updated issue: %s\n", ui.RenderPass("✓"), id)
				}

				// Track first successful update for last-touched
				if firstUpdatedID == "" {
					firstUpdatedID = id
				}
			}

			if jsonOutput && len(updatedIssues) > 0 {
				outputJSON(updatedIssues)
			}

			// Set last touched after all updates complete
			if firstUpdatedID != "" {
				SetLastTouchedID(firstUpdatedID)
			}
			return
		}

		// Direct mode
		updatedIssues := []*types.Issue{}
		var firstUpdatedID string // Track first successful update for last-touched
		for _, id := range resolvedIDs {
			// Check if issue is a template: templates are read-only
			issue, err := store.GetIssue(ctx, id)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Error getting %s: %v\n", id, err)
				continue
			}
			if err := validateIssueUpdatable(id, issue); err != nil {
				fmt.Fprintf(os.Stderr, "%s\n", err)
				continue
			}

			// Handle claim operation atomically
			if claimFlag {
				// Check if already claimed (has non-empty assignee)
				if issue.Assignee != "" {
					fmt.Fprintf(os.Stderr, "Error claiming %s: already claimed by %s\n", id, issue.Assignee)
					continue
				}
				// Atomically set assignee and status
				claimUpdates := map[string]interface{}{
					"assignee": actor,
					"status":   "in_progress",
				}
				if err := store.UpdateIssue(ctx, id, claimUpdates, actor); err != nil {
					fmt.Fprintf(os.Stderr, "Error claiming %s: %v\n", id, err)
					continue
				}
			}

			// Apply regular field updates if any
			regularUpdates := make(map[string]interface{})
			for k, v := range updates {
				if k != "add_labels" && k != "remove_labels" && k != "set_labels" && k != "parent" {
					regularUpdates[k] = v
				}
			}
			if len(regularUpdates) > 0 {
				if err := store.UpdateIssue(ctx, id, regularUpdates, actor); err != nil {
					fmt.Fprintf(os.Stderr, "Error updating %s: %v\n", id, err)
					continue
				}
			}

			// Handle label operations
			var setLabels, addLabels, removeLabels []string
			if v, ok := updates["set_labels"].([]string); ok {
				setLabels = v
			}
			if v, ok := updates["add_labels"].([]string); ok {
				addLabels = v
			}
			if v, ok := updates["remove_labels"].([]string); ok {
				removeLabels = v
			}
			if len(setLabels) > 0 || len(addLabels) > 0 || len(removeLabels) > 0 {
				if err := applyLabelUpdates(ctx, store, id, actor, setLabels, addLabels, removeLabels); err != nil {
					fmt.Fprintf(os.Stderr, "Error updating labels for %s: %v\n", id, err)
					continue
				}
			}

			// Handle parent reparenting
			if newParent, ok := updates["parent"].(string); ok {
				// Validate new parent exists (unless empty string to remove parent)
				if newParent != "" {
					parentIssue, err := store.GetIssue(ctx, newParent)
					if err != nil {
						fmt.Fprintf(os.Stderr, "Error getting parent %s: %v\n", newParent, err)
						continue
					}
					if parentIssue == nil {
						fmt.Fprintf(os.Stderr, "Error: parent issue %s not found\n", newParent)
						continue
					}
				}

				// Find and remove existing parent-child dependency
				deps, err := store.GetDependencyRecords(ctx, id)
				if err != nil {
					fmt.Fprintf(os.Stderr, "Error getting dependencies for %s: %v\n", id, err)
					continue
				}
				for _, dep := range deps {
					if dep.Type == types.DepParentChild {
						if err := store.RemoveDependency(ctx, id, dep.DependsOnID, actor); err != nil {
							fmt.Fprintf(os.Stderr, "Error removing old parent dependency: %v\n", err)
						}
						break
					}
				}

				// Add new parent-child dependency (if not removing parent)
				if newParent != "" {
					newDep := &types.Dependency{
						IssueID:     id,
						DependsOnID: newParent,
						Type:        types.DepParentChild,
					}
					if err := store.AddDependency(ctx, newDep, actor); err != nil {
						fmt.Fprintf(os.Stderr, "Error adding parent dependency: %v\n", err)
						continue
					}
				}
			}

			// Run update hook
			updatedIssue, _ := store.GetIssue(ctx, id)
			if updatedIssue != nil && hookRunner != nil {
				hookRunner.Run(hooks.EventUpdate, updatedIssue)
			}

			if jsonOutput {
				if updatedIssue != nil {
					updatedIssues = append(updatedIssues, updatedIssue)
				}
			} else {
				fmt.Printf("%s Updated issue: %s\n", ui.RenderPass("✓"), id)
			}

			// Track first successful update for last-touched
			if firstUpdatedID == "" {
				firstUpdatedID = id
			}
		}

		// Set last touched after all updates complete
		if firstUpdatedID != "" {
			SetLastTouchedID(firstUpdatedID)
		}

		// Schedule auto-flush if any issues were updated
		if len(args) > 0 {
			markDirtyAndScheduleFlush()
		}

		if jsonOutput && len(updatedIssues) > 0 {
			outputJSON(updatedIssues)
		}
	},
}

func init() {
	updateCmd.Flags().StringP("status", "s", "", "New status")
	registerPriorityFlag(updateCmd, "")
	updateCmd.Flags().String("title", "", "New title")
	updateCmd.Flags().StringP("type", "t", "", "New type (bug|feature|task|epic|chore|merge-request|molecule|gate)")
	registerCommonIssueFlags(updateCmd)
	updateCmd.Flags().String("acceptance-criteria", "", "DEPRECATED: use --acceptance")
	_ = updateCmd.Flags().MarkHidden("acceptance-criteria") // Only fails if flag missing (caught in tests)
	updateCmd.Flags().IntP("estimate", "e", 0, "Time estimate in minutes (e.g., 60 for 1 hour)")
	updateCmd.Flags().StringSlice("add-label", nil, "Add labels (repeatable)")
	updateCmd.Flags().StringSlice("remove-label", nil, "Remove labels (repeatable)")
	updateCmd.Flags().StringSlice("set-labels", nil, "Set labels, replacing all existing (repeatable)")
	updateCmd.Flags().String("parent", "", "New parent issue ID (reparents the issue, use empty string to remove parent)")
	updateCmd.Flags().Bool("claim", false, "Atomically claim the issue (sets assignee to you, status to in_progress; fails if already claimed)")
	updateCmd.Flags().String("session", "", "Claude Code session ID for status=closed (or set CLAUDE_SESSION_ID env var)")
	rootCmd.AddCommand(updateCmd)
}