package coordinator

import (
	"context"
	"fmt"
	"strings"

	"chat-agent-system/internal/contracts/vocabulary"
)

// ResolvedDoc is a uniquely resolved controlled document.
type ResolvedDoc struct {
	DocID   string
	Title   string
	State   vocabulary.DocumentState
	TaskKey string
}

// DocListItem is one candidate from the project document inventory.
type DocListItem struct {
	DocID   string
	Title   string
	State   vocabulary.DocumentState
	TaskKey string
	Aliases []string
}

// DocLister lists workflow documents for a project (typically ListWorkflowDocumentsByProject).
type DocLister func(ctx context.Context, projectID int64) ([]DocListItem, error)

// DocResolver normalizes target_doc references; never silently picks the first match.
type DocResolver interface {
	ResolveDoc(ctx context.Context, projectID int64, ref, activeDocID string) (doc *ResolvedDoc, ok bool, candidates []string, err error)
}

// ListDocResolver resolves against a DocLister inventory.
type ListDocResolver struct {
	List DocLister
}

// ResolveDoc matches by exact doc_id, then unique title/alias; empty/@active uses activeDocID.
// 0 or multiple title matches → ok=false with candidate labels (never default to first).
func (r *ListDocResolver) ResolveDoc(ctx context.Context, projectID int64, ref, activeDocID string) (*ResolvedDoc, bool, []string, error) {
	if r == nil || r.List == nil {
		return nil, false, nil, fmt.Errorf("doc resolver not configured")
	}
	ref = strings.TrimSpace(ref)
	activeDocID = strings.TrimSpace(activeDocID)
	if ref == "" || ref == "@active" || strings.EqualFold(ref, "当前受控文档") || ref == "当前文档" {
		if activeDocID == "" {
			items, err := r.List(ctx, projectID)
			if err != nil {
				return nil, false, nil, err
			}
			return nil, false, candidateLabels(items), nil
		}
		ref = activeDocID
	}

	items, err := r.List(ctx, projectID)
	if err != nil {
		return nil, false, nil, err
	}
	if len(items) == 0 {
		return nil, false, nil, nil
	}

	for _, it := range items {
		if strings.EqualFold(it.DocID, ref) {
			return toResolved(it), true, nil, nil
		}
	}

	normRef := normalizeDocLabel(ref)
	var hits []DocListItem
	for _, it := range items {
		if normalizeDocLabel(it.Title) == normRef || normalizeDocLabel(it.TaskKey) == normRef {
			hits = append(hits, it)
			continue
		}
		for _, a := range it.Aliases {
			if normalizeDocLabel(a) == normRef {
				hits = append(hits, it)
				break
			}
		}
		// loose contains only when unique later
		if strings.Contains(normalizeDocLabel(it.Title), normRef) || strings.Contains(normRef, normalizeDocLabel(it.Title)) {
			if normalizeDocLabel(it.Title) != "" && normRef != "" {
				already := false
				for _, h := range hits {
					if h.DocID == it.DocID {
						already = true
						break
					}
				}
				if !already {
					hits = append(hits, it)
				}
			}
		}
	}

	if len(hits) == 1 {
		return toResolved(hits[0]), true, nil, nil
	}
	if len(hits) == 0 {
		return nil, false, candidateLabels(items), nil
	}
	return nil, false, candidateLabels(hits), nil
}

func toResolved(it DocListItem) *ResolvedDoc {
	return &ResolvedDoc{DocID: it.DocID, Title: it.Title, State: it.State, TaskKey: it.TaskKey}
}

func candidateLabels(items []DocListItem) []string {
	out := make([]string, 0, len(items))
	for _, it := range items {
		label := it.Title
		if label == "" {
			label = it.DocID
		}
		if it.DocID != "" && it.Title != "" {
			label = fmt.Sprintf("%s（%s）", it.Title, it.DocID)
		}
		out = append(out, label)
	}
	return out
}

func normalizeDocLabel(s string) string {
	s = strings.TrimSpace(s)
	s = strings.Trim(s, "《》「」\"' ")
	s = strings.ToLower(s)
	s = strings.ReplaceAll(s, " ", "")
	s = strings.ReplaceAll(s, "　", "")
	return s
}

// PendingSupplementView is a read-only pending ledger row for dialogue answers.
type PendingSupplementView struct {
	DocID         string
	DocTitle      string
	SourceSummary string
	ImpactReason  string
	CreatedAt     string
}

// PendingSupplementReader lists undigested locked-period supplements.
type PendingSupplementReader interface {
	ListPendingSupplements(ctx context.Context, projectID int64, docID string) ([]PendingSupplementView, error)
}

// ReopenListItem is a pending reopen request shown for approve selection.
type ReopenListItem struct {
	RequestID int64
	DocTasks  []string
	Reason    string
	Status    string
}

// ReopenLister lists pending reopen requests for a project (approve path).
type ReopenLister interface {
	ListPendingReopens(ctx context.Context, projectID int64) ([]ReopenListItem, error)
}