beads/internal/importer/importer.go

package importer

import (
	"context"
	"fmt"
	"os"
	"sort"
	"strings"

	"github.com/steveyegge/beads/internal/storage"
	"github.com/steveyegge/beads/internal/storage/sqlite"
	"github.com/steveyegge/beads/internal/types"
)

// Options contains import configuration
type Options struct {
	ResolveCollisions    bool // Auto-resolve collisions by remapping to new IDs
	DryRun               bool // Preview changes without applying them
	SkipUpdate           bool // Skip updating existing issues (create-only mode)
	Strict               bool // Fail on any error (dependencies, labels, etc.)
	RenameOnImport       bool // Rename imported issues to match database prefix
	SkipPrefixValidation bool // Skip prefix validation (for auto-import)
}

// Result contains statistics about the import operation
type Result struct {
	Created          int               // New issues created
	Updated          int               // Existing issues updated
	Unchanged        int               // Existing issues that matched exactly (idempotent)
	Skipped          int               // Issues skipped (duplicates, errors)
	Collisions       int               // Collisions detected
	IDMapping        map[string]string // Mapping of remapped IDs (old -> new)
	CollisionIDs     []string          // IDs that collided
	PrefixMismatch   bool              // Prefix mismatch detected
	ExpectedPrefix   string            // Database configured prefix
	MismatchPrefixes map[string]int    // Map of mismatched prefixes to count
}

// ImportIssues handles the core import logic used by both manual and auto-import.
// This function:
// - Works with existing storage or opens direct SQLite connection if needed
// - Detects and handles collisions
// - Imports issues, dependencies, labels, and comments
// - Returns detailed results
//
// The caller is responsible for:
// - Reading and parsing JSONL into issues slice
// - Displaying results to the user
// - Setting metadata (e.g., last_import_hash)
//
// Parameters:
// - ctx: Context for cancellation
// - dbPath: Path to SQLite database file
// - store: Existing storage instance (can be nil for direct mode)
// - issues: Parsed issues from JSONL
// - opts: Import options
func ImportIssues(ctx context.Context, dbPath string, store storage.Storage, issues []*types.Issue, opts Options) (*Result, error) {
	result := &Result{
		IDMapping:        make(map[string]string),
		MismatchPrefixes: make(map[string]int),
	}

	// Get or create SQLite store
	sqliteStore, needCloseStore, err := getOrCreateStore(ctx, dbPath, store)
	if err != nil {
		return nil, err
	}
	if needCloseStore {
		defer func() { _ = sqliteStore.Close() }()
	}

	// Check and handle prefix mismatches
	if err := handlePrefixMismatch(ctx, sqliteStore, issues, opts, result); err != nil {
		return result, err
	}

	// Detect and resolve collisions
	issues, err = handleCollisions(ctx, sqliteStore, issues, opts, result)
	if err != nil {
		return result, err
	}
	if opts.DryRun && result.Collisions == 0 {
		return result, nil
	}

	// Upsert issues (create new or update existing)
	if err := upsertIssues(ctx, sqliteStore, issues, opts, result); err != nil {
		return nil, err
	}

	// Import dependencies
	if err := importDependencies(ctx, sqliteStore, issues, opts); err != nil {
		return nil, err
	}

	// Import labels
	if err := importLabels(ctx, sqliteStore, issues, opts); err != nil {
		return nil, err
	}

	// Import comments
	if err := importComments(ctx, sqliteStore, issues, opts); err != nil {
		return nil, err
	}

	// Checkpoint WAL to update main .db file timestamp
	// This ensures staleness detection sees the database as fresh
	if err := sqliteStore.CheckpointWAL(ctx); err != nil {
		// Non-fatal - just log warning
		fmt.Fprintf(os.Stderr, "Warning: failed to checkpoint WAL: %v\n", err)
	}

	return result, nil
}

// getOrCreateStore returns an existing storage or creates a new one
func getOrCreateStore(ctx context.Context, dbPath string, store storage.Storage) (*sqlite.SQLiteStorage, bool, error) {
	if store != nil {
		sqliteStore, ok := store.(*sqlite.SQLiteStorage)
		if !ok {
			return nil, false, fmt.Errorf("import requires SQLite storage backend")
		}
		return sqliteStore, false, nil
	}

	// Open direct connection for daemon mode
	if dbPath == "" {
		return nil, false, fmt.Errorf("database path not set")
	}
	sqliteStore, err := sqlite.New(dbPath)
	if err != nil {
		return nil, false, fmt.Errorf("failed to open database: %w", err)
	}

	return sqliteStore, true, nil
}

// handlePrefixMismatch checks and handles prefix mismatches
func handlePrefixMismatch(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options, result *Result) error {
	configuredPrefix, err := sqliteStore.GetConfig(ctx, "issue_prefix")
	if err != nil {
		return fmt.Errorf("failed to get configured prefix: %w", err)
	}

	// Only validate prefixes if a prefix is configured
	if strings.TrimSpace(configuredPrefix) == "" {
		if opts.RenameOnImport {
			return fmt.Errorf("cannot rename: issue_prefix not configured in database")
		}
		return nil
	}

	result.ExpectedPrefix = configuredPrefix

	// Analyze prefixes in imported issues
	for _, issue := range issues {
		prefix := extractPrefix(issue.ID)
		if prefix != configuredPrefix {
			result.PrefixMismatch = true
			result.MismatchPrefixes[prefix]++
		}
	}

	// If prefix mismatch detected and not handling it, return error or warning
	if result.PrefixMismatch && !opts.RenameOnImport && !opts.DryRun && !opts.SkipPrefixValidation {
		return fmt.Errorf("prefix mismatch detected: database uses '%s-' but found issues with prefixes: %v (use --rename-on-import to automatically fix)", configuredPrefix, getPrefixList(result.MismatchPrefixes))
	}

	// Handle rename-on-import if requested
	if result.PrefixMismatch && opts.RenameOnImport && !opts.DryRun {
		if err := RenameImportedIssuePrefixes(issues, configuredPrefix); err != nil {
			return fmt.Errorf("failed to rename prefixes: %w", err)
		}
		// After renaming, clear the mismatch flags since we fixed them
		result.PrefixMismatch = false
		result.MismatchPrefixes = make(map[string]int)
	}

	return nil
}

// handleCollisions detects and resolves ID collisions
func handleCollisions(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options, result *Result) ([]*types.Issue, error) {
	collisionResult, err := sqlite.DetectCollisions(ctx, sqliteStore, issues)
	if err != nil {
		return nil, fmt.Errorf("collision detection failed: %w", err)
	}

	result.Collisions = len(collisionResult.Collisions)
	for _, collision := range collisionResult.Collisions {
		result.CollisionIDs = append(result.CollisionIDs, collision.ID)
	}

	// Handle collisions
	if len(collisionResult.Collisions) > 0 {
		if opts.DryRun {
			return issues, nil
		}

		if !opts.ResolveCollisions {
			return nil, fmt.Errorf("collision detected for issues: %v (use --resolve-collisions to auto-resolve)", result.CollisionIDs)
		}

		// Resolve collisions by scoring and remapping
		allExistingIssues, err := sqliteStore.SearchIssues(ctx, "", types.IssueFilter{})
		if err != nil {
			return nil, fmt.Errorf("failed to get existing issues for collision resolution: %w", err)
		}

		// Score collisions
		if err := sqlite.ScoreCollisions(ctx, sqliteStore, collisionResult.Collisions, allExistingIssues); err != nil {
			return nil, fmt.Errorf("failed to score collisions: %w", err)
		}

		// Remap collisions
		idMapping, err := sqlite.RemapCollisions(ctx, sqliteStore, collisionResult.Collisions, allExistingIssues)
		if err != nil {
			return nil, fmt.Errorf("failed to remap collisions: %w", err)
		}

		result.IDMapping = idMapping
		result.Created = len(collisionResult.Collisions)

		// Remove colliding issues from the list (they're already processed)
		filteredIssues := make([]*types.Issue, 0)
		collidingIDs := make(map[string]bool)
		for _, collision := range collisionResult.Collisions {
			collidingIDs[collision.ID] = true
		}
		for _, issue := range issues {
			if !collidingIDs[issue.ID] {
				filteredIssues = append(filteredIssues, issue)
			}
		}
		return filteredIssues, nil
	}

	if opts.DryRun {
		result.Created = len(collisionResult.NewIssues)
		result.Unchanged = len(collisionResult.ExactMatches)
	}

	return issues, nil
}

// upsertIssues creates new issues or updates existing ones
func upsertIssues(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options, result *Result) error {
	var newIssues []*types.Issue
	seenNew := make(map[string]int)

	for _, issue := range issues {
		// Check if issue exists in DB
		existing, err := sqliteStore.GetIssue(ctx, issue.ID)
		if err != nil {
			return fmt.Errorf("error checking issue %s: %w", issue.ID, err)
		}

		if existing != nil {
			// Issue exists - update it unless SkipUpdate is set
			if opts.SkipUpdate {
				result.Skipped++
				continue
			}

			// Build updates map
			updates := make(map[string]interface{})
			updates["title"] = issue.Title
			updates["description"] = issue.Description
			updates["status"] = issue.Status
			updates["priority"] = issue.Priority
			updates["issue_type"] = issue.IssueType
			updates["design"] = issue.Design
			updates["acceptance_criteria"] = issue.AcceptanceCriteria
			updates["notes"] = issue.Notes

			if issue.Assignee != "" {
				updates["assignee"] = issue.Assignee
			} else {
				updates["assignee"] = nil
			}

			if issue.ExternalRef != nil && *issue.ExternalRef != "" {
				updates["external_ref"] = *issue.ExternalRef
			} else {
				updates["external_ref"] = nil
			}

			// Only update if data actually changed
			if IssueDataChanged(existing, updates) {
				if err := sqliteStore.UpdateIssue(ctx, issue.ID, updates, "import"); err != nil {
					return fmt.Errorf("error updating issue %s: %w", issue.ID, err)
				}
				result.Updated++
			} else {
				result.Unchanged++
			}
		} else {
			// New issue - check for duplicates in import batch
			if idx, seen := seenNew[issue.ID]; seen {
				if opts.Strict {
					return fmt.Errorf("duplicate issue ID %s in import (line %d)", issue.ID, idx)
				}
				result.Skipped++
				continue
			}
			seenNew[issue.ID] = len(newIssues)
			newIssues = append(newIssues, issue)
		}
	}

	// Batch create all new issues
	if len(newIssues) > 0 {
		if err := sqliteStore.CreateIssues(ctx, newIssues, "import"); err != nil {
			return fmt.Errorf("error creating issues: %w", err)
		}
		result.Created += len(newIssues)
	}

	// Sync counters after batch import
	if err := sqliteStore.SyncAllCounters(ctx); err != nil {
		return fmt.Errorf("error syncing counters: %w", err)
	}

	return nil
}

// importDependencies imports dependency relationships
func importDependencies(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options) error {
	for _, issue := range issues {
		if len(issue.Dependencies) == 0 {
			continue
		}

		// Fetch existing dependencies once per issue
		existingDeps, err := sqliteStore.GetDependencyRecords(ctx, issue.ID)
		if err != nil {
			return fmt.Errorf("error checking dependencies for %s: %w", issue.ID, err)
		}

		// Build set of existing dependencies for O(1) lookup
		existingSet := make(map[string]bool)
		for _, existing := range existingDeps {
			key := fmt.Sprintf("%s|%s", existing.DependsOnID, existing.Type)
			existingSet[key] = true
		}

		for _, dep := range issue.Dependencies {
			// Check for duplicate using set
			key := fmt.Sprintf("%s|%s", dep.DependsOnID, dep.Type)
			if existingSet[key] {
				continue
			}

			// Add dependency
			if err := sqliteStore.AddDependency(ctx, dep, "import"); err != nil {
				if opts.Strict {
					return fmt.Errorf("error adding dependency %s → %s: %w", dep.IssueID, dep.DependsOnID, err)
				}
				continue
			}
		}
	}

	return nil
}

// importLabels imports labels for issues
func importLabels(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options) error {
	for _, issue := range issues {
		if len(issue.Labels) == 0 {
			continue
		}

		// Get current labels
		currentLabels, err := sqliteStore.GetLabels(ctx, issue.ID)
		if err != nil {
			return fmt.Errorf("error getting labels for %s: %w", issue.ID, err)
		}

		currentLabelSet := make(map[string]bool)
		for _, label := range currentLabels {
			currentLabelSet[label] = true
		}

		// Add missing labels
		for _, label := range issue.Labels {
			if !currentLabelSet[label] {
				if err := sqliteStore.AddLabel(ctx, issue.ID, label, "import"); err != nil {
					if opts.Strict {
						return fmt.Errorf("error adding label %s to %s: %w", label, issue.ID, err)
					}
					continue
				}
			}
		}
	}

	return nil
}

// importComments imports comments for issues
func importComments(ctx context.Context, sqliteStore *sqlite.SQLiteStorage, issues []*types.Issue, opts Options) error {
	for _, issue := range issues {
		if len(issue.Comments) == 0 {
			continue
		}

		// Get current comments to avoid duplicates
		currentComments, err := sqliteStore.GetIssueComments(ctx, issue.ID)
		if err != nil {
			return fmt.Errorf("error getting comments for %s: %w", issue.ID, err)
		}

		// Build a set of existing comments (by author+normalized text)
		existingComments := make(map[string]bool)
		for _, c := range currentComments {
			key := fmt.Sprintf("%s:%s", c.Author, strings.TrimSpace(c.Text))
			existingComments[key] = true
		}

		// Add missing comments
		for _, comment := range issue.Comments {
			key := fmt.Sprintf("%s:%s", comment.Author, strings.TrimSpace(comment.Text))
			if !existingComments[key] {
				if _, err := sqliteStore.AddIssueComment(ctx, issue.ID, comment.Author, comment.Text); err != nil {
					if opts.Strict {
						return fmt.Errorf("error adding comment to %s: %w", issue.ID, err)
					}
					continue
				}
			}
		}
	}

	return nil
}

// Helper functions

func extractPrefix(issueID string) string {
	parts := strings.SplitN(issueID, "-", 2)
	if len(parts) < 2 {
		return ""
	}
	return parts[0]
}

func getPrefixList(prefixes map[string]int) []string {
	var result []string
	keys := make([]string, 0, len(prefixes))
	for k := range prefixes {
		keys = append(keys, k)
	}
	sort.Strings(keys)

	for _, prefix := range keys {
		count := prefixes[prefix]
		result = append(result, fmt.Sprintf("%s- (%d issues)", prefix, count))
	}
	return result
}