package service

import (
	"infinite-canvas/backend/internal/model"

	"golang.org/x/sync/errgroup"
)

type ProjectCore struct {
	Project model.Project `json:"project"`
}

type ProjectUnitSummaries struct {
	Units        []model.ProjectUnit `json:"units"`
	CanvasCounts map[string]int64    `json:"canvasCounts"`
}

type ProjectOverview struct {
	Metrics ProjectOverviewMetrics `json:"metrics"`
	Units   []ProjectOverviewUnit  `json:"units"`
}

type ProjectOverviewMetrics struct {
	UnitCount             int64 `json:"unitCount"`
	CompletedUnitCount    int64 `json:"completedUnitCount"`
	TotalWordCount        int64 `json:"totalWordCount"`
	UnitsWithoutText      int64 `json:"unitsWithoutText"`
	UnitsWithoutShots     int64 `json:"unitsWithoutShots"`
	CanvasCount           int64 `json:"canvasCount"`
	AssetCount            int64 `json:"assetCount"`
	ShotCount             int64 `json:"shotCount"`
	PendingCandidateCount int64 `json:"pendingCandidateCount"`
	ReadyStoryboardCount  int64 `json:"readyStoryboardCount"`
	ReadyPrevizCount      int64 `json:"readyPrevizCount"`
	ReadyVideoCount       int64 `json:"readyVideoCount"`
	StaleArtifactCount    int64 `json:"staleArtifactCount"`
}

type ProjectOverviewUnit struct {
	Unit           model.ProjectUnit `json:"unit"`
	ShotCount      int64             `json:"shotCount"`
	CandidateCount int64             `json:"candidateCount"`
	CanvasCount    int64             `json:"canvasCount"`
}

type ProjectUnitWorkspace struct {
	Unit            model.ProjectUnit             `json:"unit"`
	Workflows       []ProjectWorkflowDetail       `json:"workflows"`
	Shots           []model.Shot                  `json:"shots"`
	ShotRevisions   []model.ShotRevision          `json:"shotRevisions"`
	ShotArtifacts   []model.ShotArtifact          `json:"shotArtifacts"`
	ShotReferences  []model.ShotAssetReference    `json:"shotReferences"`
	AssetCandidates []model.ProjectAssetCandidate `json:"assetCandidates"`
	Assets          []ProjectAssetSummary         `json:"assets"`
	Tasks           []TaskSummary                 `json:"tasks"`
}

type ProjectCanvasPage struct {
	Canvases        []model.CanvasProject  `json:"canvases"`
	CanvasUnitLinks []model.CanvasUnitLink `json:"canvasUnitLinks"`
	Page            int                    `json:"page"`
	PageSize        int                    `json:"pageSize"`
	Total           int64                  `json:"total"`
	HasMore         bool                   `json:"hasMore"`
}

type ProjectAssetCandidatePage struct {
	Candidates []model.ProjectAssetCandidate `json:"candidates"`
	Page       int                           `json:"page"`
	PageSize   int                           `json:"pageSize"`
	Total      int64                         `json:"total"`
	HasMore    bool                          `json:"hasMore"`
}

type ProjectAssetPage struct {
	Assets         []ProjectAssetSummary `json:"assets"`
	CategoryCounts map[string]int64      `json:"categoryCounts"`
	FolderCounts   map[string]int64      `json:"folderCounts"`
	Page           int                   `json:"page"`
	PageSize       int                   `json:"pageSize"`
	Total          int64                 `json:"total"`
	HasMore        bool                  `json:"hasMore"`
}

func (s *Service) ProjectCore(userID string, projectID string) (ProjectCore, error) {
	project, err := s.repo.ProjectForUser(userID, projectID)
	if err != nil {
		return ProjectCore{}, err
	}
	if s.reconcileCharacterTurnaroundTasks(userID, project.ID) {
		project, err = s.repo.ProjectForUser(userID, projectID)
		if err != nil {
			return ProjectCore{}, err
		}
	}
	return ProjectCore{Project: *project}, nil
}

func (s *Service) ProjectUnitSummaries(userID string, projectID string) (ProjectUnitSummaries, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectUnitSummaries{}, err
	}
	var units []model.ProjectUnit
	var canvasCounts map[string]int64
	var group errgroup.Group
	group.Go(func() error {
		var err error
		units, err = s.repo.ProjectUnitSummaries(projectID)
		return err
	})
	group.Go(func() error {
		var err error
		canvasCounts, err = s.repo.ProjectUnitCanvasCounts(projectID)
		return err
	})
	if err := group.Wait(); err != nil {
		return ProjectUnitSummaries{}, err
	}
	return ProjectUnitSummaries{Units: units, CanvasCounts: canvasCounts}, nil
}

func (s *Service) ProjectOverview(userID string, projectID string) (ProjectOverview, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectOverview{}, err
	}
	var metrics ProjectOverviewMetrics
	var units []ProjectOverviewUnit
	var group errgroup.Group
	group.Go(func() error {
		row, err := s.repo.ProjectOverviewMetrics(projectID)
		if err != nil {
			return err
		}
		metrics = ProjectOverviewMetrics{
			UnitCount: row.UnitCount, CompletedUnitCount: row.CompletedUnitCount, TotalWordCount: row.TotalWordCount,
			UnitsWithoutText: row.UnitsWithoutText, UnitsWithoutShots: row.UnitsWithoutShots, CanvasCount: row.CanvasCount,
			AssetCount: row.AssetCount, ShotCount: row.ShotCount, PendingCandidateCount: row.PendingCandidateCount,
			ReadyStoryboardCount: row.ReadyStoryboardCount, ReadyPrevizCount: row.ReadyPrevizCount, ReadyVideoCount: row.ReadyVideoCount,
			StaleArtifactCount: row.StaleArtifactCount,
		}
		return nil
	})
	group.Go(func() error {
		rows, err := s.repo.ProjectOverviewUnits(projectID, 8)
		if err != nil {
			return err
		}
		units = make([]ProjectOverviewUnit, 0, len(rows))
		for _, row := range rows {
			units = append(units, ProjectOverviewUnit{Unit: row.ProjectUnit, ShotCount: row.ShotCount, CandidateCount: row.CandidateCount, CanvasCount: row.CanvasCount})
		}
		return nil
	})
	if err := group.Wait(); err != nil {
		return ProjectOverview{}, err
	}
	return ProjectOverview{Metrics: metrics, Units: units}, nil
}

func (s *Service) ProjectUnitWorkspace(userID string, projectID string, unitID string) (ProjectUnitWorkspace, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectUnitWorkspace{}, err
	}
	unit, err := s.repo.ProjectUnit(projectID, unitID)
	if err != nil {
		return ProjectUnitWorkspace{}, err
	}
	result := ProjectUnitWorkspace{Unit: *unit}
	var projectTasks []TaskSummary
	var group errgroup.Group
	group.Go(func() error {
		var err error
		result.Shots, err = s.repo.ProjectUnitShots(projectID, unitID)
		return err
	})
	group.Go(func() error {
		var err error
		result.ShotRevisions, err = s.repo.ProjectUnitShotRevisions(projectID, unitID)
		return err
	})
	group.Go(func() error {
		var err error
		result.ShotArtifacts, err = s.repo.ProjectUnitShotArtifacts(projectID, unitID)
		return err
	})
	group.Go(func() error {
		var err error
		result.ShotReferences, err = s.repo.ProjectUnitShotAssetReferences(projectID, unitID)
		return err
	})
	group.Go(func() error {
		var err error
		result.AssetCandidates, err = s.repo.ProjectUnitAssetCandidates(projectID, unitID)
		return err
	})
	group.Go(func() error {
		assets, err := s.repo.ProjectUnitAssets(userID, projectID, unitID)
		if err != nil {
			return err
		}
		result.Assets = make([]ProjectAssetSummary, len(assets))
		var summaries errgroup.Group
		summaries.SetLimit(8)
		for index := range assets {
			index := index
			summaries.Go(func() error {
				summary, summaryErr := s.projectAssetSummary(userID, projectID, &assets[index])
				if summaryErr == nil {
					result.Assets[index] = summary
				}
				return summaryErr
			})
		}
		return summaries.Wait()
	})
	group.Go(func() error {
		instances, err := s.repo.ProjectWorkflowInstancesForUnit(projectID, unitID)
		if err != nil {
			return err
		}
		result.Workflows = make([]ProjectWorkflowDetail, 0, len(instances))
		for _, instance := range instances {
			steps, stepsErr := s.repo.WorkflowSteps(instance.ID)
			if stepsErr != nil {
				return stepsErr
			}
			result.Workflows = append(result.Workflows, ProjectWorkflowDetail{Instance: instance, Steps: steps})
		}
		return nil
	})
	group.Go(func() error {
		recent, err := s.TasksWithOptions(userID, TaskListOptions{Limit: 100, ProjectID: projectID})
		if err != nil {
			return err
		}
		active, err := s.TasksWithOptions(userID, TaskListOptions{Limit: 100, ProjectID: projectID, ActiveOnly: true})
		if err != nil {
			return err
		}
		seen := make(map[string]struct{}, len(recent)+len(active))
		projectTasks = make([]TaskSummary, 0, len(recent)+len(active))
		for _, task := range append(active, recent...) {
			if _, exists := seen[task.ID]; exists {
				continue
			}
			seen[task.ID] = struct{}{}
			projectTasks = append(projectTasks, task)
		}
		return nil
	})
	if err := group.Wait(); err != nil {
		return ProjectUnitWorkspace{}, err
	}
	shotIDs := make(map[string]struct{}, len(result.Shots))
	for _, shot := range result.Shots {
		shotIDs[shot.ID] = struct{}{}
	}
	result.Tasks = make([]TaskSummary, 0, len(projectTasks))
	for _, task := range projectTasks {
		context := task.ClientContext
		if context == nil {
			continue
		}
		_, belongsToShot := shotIDs[context.ShotID]
		if context.ChapterID == unitID || belongsToShot {
			result.Tasks = append(result.Tasks, task)
		}
	}
	return result, nil
}

func (s *Service) ProjectCanvasesPage(userID string, projectID string, page int, pageSize int) (ProjectCanvasPage, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectCanvasPage{}, err
	}
	page, pageSize = normalizeProjectPage(page, pageSize, 100)
	canvases, total, err := s.repo.ProjectCanvasSummariesPage(userID, projectID, page, pageSize)
	if err != nil {
		return ProjectCanvasPage{}, err
	}
	ids := make([]string, 0, len(canvases))
	for _, canvas := range canvases {
		ids = append(ids, canvas.ID)
	}
	links, err := s.repo.ProjectCanvasUnitLinksForCanvases(projectID, ids)
	if err != nil {
		return ProjectCanvasPage{}, err
	}
	return ProjectCanvasPage{Canvases: canvases, CanvasUnitLinks: links, Page: page, PageSize: pageSize, Total: total, HasMore: int64(page*pageSize) < total}, nil
}

func (s *Service) ProjectAssetCandidatesPage(userID string, projectID string, page int, pageSize int, unitID string, status string, category string) (ProjectAssetCandidatePage, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectAssetCandidatePage{}, err
	}
	page, pageSize = normalizeProjectPage(page, pageSize, 200)
	candidates, total, err := s.repo.ProjectAssetCandidatesPage(projectID, page, pageSize, unitID, status, category)
	if err != nil {
		return ProjectAssetCandidatePage{}, err
	}
	return ProjectAssetCandidatePage{Candidates: candidates, Page: page, PageSize: pageSize, Total: total, HasMore: int64(page*pageSize) < total}, nil
}

func (s *Service) ProjectAssetsPage(userID string, projectID string, page int, pageSize int, category string, mediaType string, status string, folderID *string, query string) (ProjectAssetPage, error) {
	if _, err := s.repo.ProjectForUser(userID, projectID); err != nil {
		return ProjectAssetPage{}, err
	}
	page, pageSize = normalizeProjectPage(page, pageSize, 80)
	assets, total, err := s.repo.ProjectAssetsPage(userID, projectID, page, pageSize, category, mediaType, status, folderID, query)
	if err != nil {
		return ProjectAssetPage{}, err
	}
	summaries := make([]ProjectAssetSummary, len(assets))
	var group errgroup.Group
	group.SetLimit(8)
	for index := range assets {
		index := index
		group.Go(func() error {
			summary, summaryErr := s.projectAssetSummary(userID, projectID, &assets[index])
			if summaryErr != nil {
				return summaryErr
			}
			summaries[index] = summary
			return nil
		})
	}
	if err := group.Wait(); err != nil {
		return ProjectAssetPage{}, err
	}
	categoryRows, folderRows, err := s.repo.ProjectAssetFacets(projectID)
	if err != nil {
		return ProjectAssetPage{}, err
	}
	categoryCounts := make(map[string]int64, len(categoryRows))
	for _, row := range categoryRows {
		categoryCounts[row.Key] = row.Count
	}
	folderCounts := make(map[string]int64, len(folderRows))
	for _, row := range folderRows {
		folderCounts[row.Key] = row.Count
	}
	return ProjectAssetPage{Assets: summaries, CategoryCounts: categoryCounts, FolderCounts: folderCounts, Page: page, PageSize: pageSize, Total: total, HasMore: int64(page*pageSize) < total}, nil
}

func normalizeProjectPage(page int, pageSize int, maximum int) (int, int) {
	if page < 1 {
		page = 1
	}
	if pageSize < 1 {
		pageSize = 40
	}
	if pageSize > maximum {
		pageSize = maximum
	}
	return page, pageSize
}