package postgres

import (
	"context"
	_ "embed"
	"encoding/json"
	"errors"
	"fmt"
	"strings"
	"time"

	"img_infinite_canvas/internal/domain/design"
	sqlcdb "img_infinite_canvas/internal/infrastructure/postgres/db"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
	"github.com/jackc/pgx/v5/pgxpool"
)

//go:embed schema.sql
var schemaSQL string

type ProjectRepository struct {
	pool *pgxpool.Pool
}

func NewProjectRepository(ctx context.Context, dataSource string) (*ProjectRepository, error) {
	pool, err := pgxpool.New(ctx, dataSource)
	if err != nil {
		return nil, err
	}
	if _, err := pool.Exec(ctx, schemaSQL); err != nil {
		pool.Close()
		return nil, err
	}
	return &ProjectRepository{pool: pool}, nil
}

func (r *ProjectRepository) Close() {
	r.pool.Close()
}

func (r *ProjectRepository) List(ctx context.Context) ([]design.ProjectSummary, error) {
	rows, err := sqlcdb.New(r.pool).ListProjects(ctx, toPGUUID(design.UserIDFromContext(ctx)))
	if err != nil {
		return nil, err
	}

	items := make([]design.ProjectSummary, 0, len(rows))
	for _, row := range rows {
		items = append(items, design.ProjectSummary{
			ID:        row.ID,
			UserID:    fromPGUUID(row.UserID),
			Title:     row.Title,
			Brief:     row.Brief,
			Status:    design.ProjectStatus(row.Status),
			Thumbnail: row.Thumbnail,
			UpdatedAt: row.UpdatedAt.Time,
		})
	}
	return items, nil
}

func (r *ProjectRepository) ListPage(ctx context.Context, limit int64, offset int64) ([]design.ProjectSummary, error) {
	if limit <= 0 {
		return []design.ProjectSummary{}, nil
	}
	if offset < 0 {
		offset = 0
	}
	rows, err := sqlcdb.New(r.pool).ListProjectsPage(ctx, sqlcdb.ListProjectsPageParams{
		UserID: toPGUUID(design.UserIDFromContext(ctx)),
		Limit:  int32(limit),
		Offset: int32(offset),
	})
	if err != nil {
		return nil, err
	}

	items := make([]design.ProjectSummary, 0, len(rows))
	for _, row := range rows {
		items = append(items, design.ProjectSummary{
			ID:        row.ID,
			UserID:    fromPGUUID(row.UserID),
			Title:     row.Title,
			Brief:     row.Brief,
			Status:    design.ProjectStatus(row.Status),
			Thumbnail: row.Thumbnail,
			UpdatedAt: row.UpdatedAt.Time,
		})
	}
	return items, nil
}

func (r *ProjectRepository) Get(ctx context.Context, id string) (design.Project, error) {
	q := sqlcdb.New(r.pool)
	userID := design.UserIDFromContext(ctx)
	pgUserID := toPGUUID(userID)
	row, err := q.GetProject(ctx, sqlcdb.GetProjectParams{ID: id, UserID: pgUserID})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return design.Project{}, design.ErrNotFound
		}
		return design.Project{}, err
	}

	nodes, err := q.ListNodesByProject(ctx, sqlcdb.ListNodesByProjectParams{ProjectID: id, UserID: pgUserID})
	if err != nil {
		return design.Project{}, err
	}
	connections, err := q.ListConnectionsByProject(ctx, sqlcdb.ListConnectionsByProjectParams{ProjectID: id, UserID: pgUserID})
	if err != nil {
		return design.Project{}, err
	}
	messages, err := q.ListMessagesByProject(ctx, sqlcdb.ListMessagesByProjectParams{ProjectID: id, UserID: pgUserID})
	if err != nil {
		return design.Project{}, err
	}

	project := design.Project{
		ID:           row.ID,
		UserID:       fromPGUUID(row.UserID),
		Title:        row.Title,
		Brief:        row.Brief,
		Status:       design.ProjectStatus(row.Status),
		Thumbnail:    row.Thumbnail,
		Version:      row.Version,
		SnapshotID:   row.SnapshotID,
		Canvas:       row.Canvas,
		LastThreadID: row.LastThreadID,
		UpdatedAt:    row.UpdatedAt.Time,
		Viewport: design.Viewport{
			X: row.ViewportX,
			Y: row.ViewportY,
			K: row.ViewportK,
		},
		Nodes:       mapNodes(nodes),
		Connections: mapConnections(connections),
		Messages:    mapMessages(messages),
	}
	if err := r.applyCurrentSnapshot(ctx, q, &project); err != nil {
		return design.Project{}, err
	}
	return project, nil
}

func (r *ProjectRepository) Save(ctx context.Context, project design.Project) error {
	project.UserID = repositoryUserID(ctx, project.UserID)
	tx, err := r.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer tx.Rollback(ctx)

	q := sqlcdb.New(r.pool).WithTx(tx)
	if err := q.UpsertProject(ctx, sqlcdb.UpsertProjectParams{
		ID:           project.ID,
		UserID:       toPGUUID(project.UserID),
		Title:        project.Title,
		Brief:        project.Brief,
		Status:       string(project.Status),
		Thumbnail:    project.Thumbnail,
		Canvas:       project.Canvas,
		Version:      project.Version,
		SnapshotID:   project.SnapshotID,
		LastThreadID: project.LastThreadID,
		ViewportX:    project.Viewport.X,
		ViewportY:    project.Viewport.Y,
		ViewportK:    project.Viewport.K,
		UpdatedAt:    pgtype.Timestamptz{Time: project.UpdatedAt, Valid: true},
	}); err != nil {
		return err
	}

	if err := q.DeleteConnectionsByProject(ctx, sqlcdb.DeleteConnectionsByProjectParams{ProjectID: project.ID, UserID: toPGUUID(project.UserID)}); err != nil {
		return err
	}
	if err := q.DeleteNodesByProject(ctx, sqlcdb.DeleteNodesByProjectParams{ProjectID: project.ID, UserID: toPGUUID(project.UserID)}); err != nil {
		return err
	}
	if err := q.DeleteMessagesByProject(ctx, sqlcdb.DeleteMessagesByProjectParams{ProjectID: project.ID, UserID: toPGUUID(project.UserID)}); err != nil {
		return err
	}

	for index, node := range project.Nodes {
		if err := q.UpsertCanvasNode(ctx, sqlcdb.UpsertCanvasNodeParams{
			ID:             node.ID,
			ProjectID:      project.ID,
			UserID:         toPGUUID(project.UserID),
			NodeType:       string(node.Type),
			Title:          node.Title,
			X:              node.X,
			Y:              node.Y,
			Width:          node.Width,
			Height:         node.Height,
			Content:        node.Content,
			Tone:           node.Tone,
			Status:         node.Status,
			SortOrder:      int32(index),
			ParentID:       node.ParentID,
			LayerRole:      node.LayerRole,
			FontSize:       node.FontSize,
			FontFamily:     node.FontFamily,
			FontWeight:     node.FontWeight,
			Color:          node.Color,
			TextAlign:      node.TextAlign,
			LineHeight:     node.LineHeight,
			LetterSpacing:  node.LetterSpacing,
			TextDecoration: node.TextDecoration,
			TextTransform:  node.TextTransform,
			Opacity:        node.Opacity,
			FillColor:      node.FillColor,
			StrokeColor:    node.StrokeColor,
			StrokeWidth:    node.StrokeWidth,
			StrokeStyle:    node.StrokeStyle,
			FlipX:          node.FlipX,
			FlipY:          node.FlipY,
			Rotation:       node.Rotation,
		}); err != nil {
			return err
		}
	}
	for _, connection := range project.Connections {
		if err := q.CreateConnection(ctx, sqlcdb.CreateConnectionParams{
			ID:         connection.ID,
			ProjectID:  project.ID,
			UserID:     toPGUUID(project.UserID),
			FromNodeID: connection.FromNodeID,
			ToNodeID:   connection.ToNodeID,
		}); err != nil {
			return err
		}
	}
	for _, message := range project.Messages {
		if err := q.CreateMessage(ctx, sqlcdb.CreateMessageParams{
			ID:          message.ID,
			ProjectID:   project.ID,
			UserID:      toPGUUID(project.UserID),
			Role:        message.Role,
			MessageType: message.Type,
			Title:       message.Title,
			Content:     message.Content,
			ThreadID:    message.ThreadID,
			ActionID:    message.ActionID,
			StepID:      message.StepID,
			ToolCallID:  message.ToolCallID,
			Name:        message.Name,
			ToolHint:    message.ToolHint,
			Status:      message.Status,
			CreatedAt:   pgtype.Timestamptz{Time: message.CreatedAt, Valid: true},
		}); err != nil {
			return err
		}
	}
	if err := r.createCanvasSnapshot(ctx, q, project); err != nil {
		return err
	}
	if err := insertProjectOutboxEvent(ctx, tx, project, "project.updated"); err != nil {
		return err
	}

	return tx.Commit(ctx)
}

func (r *ProjectRepository) SaveCanvas(ctx context.Context, project design.Project, baseVersion string) error {
	project.UserID = repositoryUserID(ctx, project.UserID)
	tx, err := r.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer tx.Rollback(ctx)

	q := sqlcdb.New(r.pool).WithTx(tx)
	locked, err := q.LockProject(ctx, sqlcdb.LockProjectParams{ID: project.ID, UserID: toPGUUID(project.UserID)})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return design.ErrNotFound
		}
		return err
	}
	baseVersion = strings.TrimSpace(baseVersion)
	if baseVersion != "" && locked.Version != "" && baseVersion != locked.Version {
		return fmt.Errorf("%w: expected %s but current version is %s", design.ErrConflict, baseVersion, locked.Version)
	}
	if err := r.createCanvasSnapshot(ctx, q, project); err != nil {
		return err
	}
	if err := q.UpdateProjectCanvasSnapshot(ctx, sqlcdb.UpdateProjectCanvasSnapshotParams{
		ID:         project.ID,
		UserID:     toPGUUID(project.UserID),
		Thumbnail:  project.Thumbnail,
		Canvas:     project.Canvas,
		Version:    project.Version,
		SnapshotID: project.SnapshotID,
		ViewportX:  project.Viewport.X,
		ViewportY:  project.Viewport.Y,
		ViewportK:  project.Viewport.K,
		UpdatedAt:  pgtype.Timestamptz{Time: project.UpdatedAt, Valid: true},
	}); err != nil {
		return err
	}
	if err := insertProjectOutboxEvent(ctx, tx, project, "canvas.snapshot.created"); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

func (r *ProjectRepository) Delete(ctx context.Context, id string) error {
	q := sqlcdb.New(r.pool)
	userID := design.UserIDFromContext(ctx)
	pgUserID := toPGUUID(userID)
	project, err := q.GetProject(ctx, sqlcdb.GetProjectParams{ID: id, UserID: pgUserID})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return design.ErrNotFound
		}
		return err
	}
	tx, err := r.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer tx.Rollback(ctx)
	qtx := sqlcdb.New(r.pool).WithTx(tx)
	if err := qtx.DeleteProject(ctx, sqlcdb.DeleteProjectParams{ID: id, UserID: pgUserID}); err != nil {
		return err
	}
	if err := insertProjectOutboxEvent(ctx, tx, design.Project{ID: project.ID, UserID: fromPGUUID(project.UserID), LastThreadID: project.LastThreadID, UpdatedAt: project.UpdatedAt.Time}, "project.deleted"); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

func (r *ProjectRepository) SaveMockupBlob(ctx context.Context, blob design.MockupBlobData) error {
	if strings.TrimSpace(blob.DataID) == "" || len(blob.Data) == 0 {
		return design.ErrInvalidInput
	}
	createdAt := blob.CreatedAt
	if createdAt.IsZero() {
		createdAt = time.Now()
	}
	_, err := r.pool.Exec(ctx, `
INSERT INTO mockup_blobs (data_id, width, height, data, created_at)
VALUES ($1, $2, $3, $4, $5)
ON CONFLICT (data_id) DO UPDATE SET
    width = EXCLUDED.width,
    height = EXCLUDED.height,
    data = EXCLUDED.data
`, blob.DataID, blob.Width, blob.Height, blob.Data, pgtype.Timestamptz{Time: createdAt, Valid: true})
	return err
}

func (r *ProjectRepository) GetMockupBlob(ctx context.Context, dataID string) (design.MockupBlobData, error) {
	dataID = strings.TrimSpace(dataID)
	if dataID == "" {
		return design.MockupBlobData{}, design.ErrNotFound
	}
	var blob design.MockupBlobData
	var createdAt pgtype.Timestamptz
	err := r.pool.QueryRow(ctx, `
SELECT data_id, width, height, data, created_at
FROM mockup_blobs
WHERE data_id = $1
`, dataID).Scan(&blob.DataID, &blob.Width, &blob.Height, &blob.Data, &createdAt)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return design.MockupBlobData{}, design.ErrNotFound
		}
		return design.MockupBlobData{}, err
	}
	if createdAt.Valid {
		blob.CreatedAt = createdAt.Time
	}
	blob.Data = append([]byte(nil), blob.Data...)
	return blob, nil
}

func (r *ProjectRepository) applyCurrentSnapshot(ctx context.Context, q *sqlcdb.Queries, project *design.Project) error {
	if project == nil || strings.TrimSpace(project.SnapshotID) == "" {
		return nil
	}
	snapshot, err := q.GetCanvasSnapshot(ctx, sqlcdb.GetCanvasSnapshotParams{
		ID:        project.SnapshotID,
		ProjectID: project.ID,
		UserID:    toPGUUID(project.UserID),
	})
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil
		}
		return err
	}
	var viewport design.Viewport
	var nodes []design.Node
	var connections []design.Connection
	if err := json.Unmarshal(snapshot.ViewportJson, &viewport); err != nil {
		return err
	}
	if err := json.Unmarshal(snapshot.NodesJson, &nodes); err != nil {
		return err
	}
	if err := json.Unmarshal(snapshot.ConnectionsJson, &connections); err != nil {
		return err
	}
	project.Viewport = viewport
	project.Nodes = nodes
	project.Connections = connections
	project.Canvas = snapshot.Canvas
	project.Version = snapshot.Version
	return nil
}

func (r *ProjectRepository) createCanvasSnapshot(ctx context.Context, q *sqlcdb.Queries, project design.Project) error {
	if strings.TrimSpace(project.SnapshotID) == "" || strings.TrimSpace(project.Canvas) == "" {
		return nil
	}
	viewport, err := json.Marshal(project.Viewport)
	if err != nil {
		return err
	}
	nodes, err := json.Marshal(project.Nodes)
	if err != nil {
		return err
	}
	connections, err := json.Marshal(project.Connections)
	if err != nil {
		return err
	}
	return q.CreateCanvasSnapshot(ctx, sqlcdb.CreateCanvasSnapshotParams{
		ID:              project.SnapshotID,
		ProjectID:       project.ID,
		UserID:          toPGUUID(project.UserID),
		Version:         project.Version,
		Canvas:          project.Canvas,
		ViewportJson:    viewport,
		NodesJson:       nodes,
		ConnectionsJson: connections,
		CreatedAt:       pgtype.Timestamptz{Time: project.UpdatedAt, Valid: true},
	})
}

func repositoryUserID(ctx context.Context, userID string) string {
	userID = strings.TrimSpace(userID)
	if userID != "" {
		return design.NormalizeUserID(userID)
	}
	return design.UserIDFromContext(ctx)
}

func toPGUUID(userID string) pgtype.UUID {
	parsed, err := uuid.Parse(design.NormalizeUserID(userID))
	if err != nil {
		parsed = uuid.MustParse(design.DefaultUserID)
	}
	return pgtype.UUID{Bytes: parsed, Valid: true}
}

func fromPGUUID(value pgtype.UUID) string {
	if !value.Valid {
		return design.DefaultUserID
	}
	return uuid.UUID(value.Bytes).String()
}

func insertProjectOutboxEvent(ctx context.Context, tx pgx.Tx, project design.Project, eventType string) error {
	eventID := uuid.NewString()
	createdAt := project.UpdatedAt
	if createdAt.IsZero() {
		createdAt = time.Now()
	}
	payload, err := json.Marshal(map[string]any{
		"id":         eventID,
		"type":       eventType,
		"userId":     project.UserID,
		"projectId":  project.ID,
		"threadId":   project.LastThreadID,
		"version":    project.Version,
		"snapshotId": project.SnapshotID,
		"createdAt":  createdAt.UTC().Format(time.RFC3339Nano),
	})
	if err != nil {
		return err
	}
	_, err = tx.Exec(ctx, `
INSERT INTO outbox_events (id, user_id, aggregate_type, aggregate_id, event_type, thread_id, payload_json, status, created_at)
VALUES ($1, $2, 'project', $3, $4, $5, $6, 'pending', $7)
`, eventID, toPGUUID(project.UserID), project.ID, eventType, project.LastThreadID, payload, pgtype.Timestamptz{Time: createdAt, Valid: true})
	return err
}

func mapNodes(rows []sqlcdb.CanvasNode) []design.Node {
	nodes := make([]design.Node, 0, len(rows))
	for _, row := range rows {
		nodes = append(nodes, design.Node{
			ID:             row.ID,
			Type:           design.NodeType(row.NodeType),
			Title:          row.Title,
			X:              row.X,
			Y:              row.Y,
			Width:          row.Width,
			Height:         row.Height,
			Content:        row.Content,
			Tone:           row.Tone,
			Status:         row.Status,
			ParentID:       row.ParentID,
			LayerRole:      row.LayerRole,
			FontSize:       row.FontSize,
			FontFamily:     row.FontFamily,
			FontWeight:     row.FontWeight,
			Color:          row.Color,
			TextAlign:      row.TextAlign,
			LineHeight:     row.LineHeight,
			LetterSpacing:  row.LetterSpacing,
			TextDecoration: row.TextDecoration,
			TextTransform:  row.TextTransform,
			Opacity:        row.Opacity,
			FillColor:      row.FillColor,
			StrokeColor:    row.StrokeColor,
			StrokeWidth:    row.StrokeWidth,
			StrokeStyle:    row.StrokeStyle,
			FlipX:          row.FlipX,
			FlipY:          row.FlipY,
			Rotation:       row.Rotation,
		})
	}
	return nodes
}

func mapConnections(rows []sqlcdb.CanvasConnection) []design.Connection {
	connections := make([]design.Connection, 0, len(rows))
	for _, row := range rows {
		connections = append(connections, design.Connection{
			ID:         row.ID,
			FromNodeID: row.FromNodeID,
			ToNodeID:   row.ToNodeID,
		})
	}
	return connections
}

func mapMessages(rows []sqlcdb.AgentMessage) []design.Message {
	messages := make([]design.Message, 0, len(rows))
	for _, row := range rows {
		messages = append(messages, design.Message{
			ID:         row.ID,
			Role:       row.Role,
			Type:       row.MessageType,
			Title:      row.Title,
			Content:    row.Content,
			ThreadID:   row.ThreadID,
			ActionID:   row.ActionID,
			StepID:     row.StepID,
			ToolCallID: row.ToolCallID,
			Name:       row.Name,
			ToolHint:   row.ToolHint,
			Status:     row.Status,
			CreatedAt:  row.CreatedAt.Time,
		})
	}
	return messages
}