package postgres

import (
	"context"
	"database/sql"
	"git.aiterp.net/rpdata/api/database/postgres/psqlcore"
	"git.aiterp.net/rpdata/api/internal/generate"
	"git.aiterp.net/rpdata/api/models"
)

type storyRepository struct {
	insertWithIDs bool
	db            *sql.DB
}

func (r *storyRepository) Find(ctx context.Context, id string) (*models.Story, error) {
	q := psqlcore.New(r.db)
	story, err := q.SelectStory(ctx, id)
	if err != nil {
		return nil, err
	}

	tags, err := q.SelectTagsByTarget(ctx, psqlcore.SelectTagsByTargetParams{
		TargetKind: "Story",
		TargetID:   story.ID,
	})
	if err != nil && err != sql.ErrNoRows {
		return nil, err
	}

	return r.story(story, tags), nil
}

func (r *storyRepository) List(ctx context.Context, filter models.StoryFilter) ([]*models.Story, error) {
	q := psqlcore.New(r.db)
	params := psqlcore.SelectStoriesParams{LimitSize: 0}

	if len(filter.Tags) > 0 {
		targets, err := q.SelectTargetsByTags(ctx, psqlcore.SelectTargetsByTagsParams{
			TagNames:   models.EncodeTagArray(filter.Tags),
			TargetKind: "Story",
		})
		if err != nil && err != sql.ErrNoRows {
			return nil, err
		}

		if len(params.Ids) == 0 {
			return []*models.Story{}, nil
		}

		params.FilterID = true
		params.Ids = targets
	}
	if filter.Author != nil {
		params.FilterAuthor = true
		params.Author = *filter.Author
	}
	if filter.Category != nil {
		params.FilterCategory = true
		params.Category = string(*filter.Category)
	}
	if !filter.EarliestFictionalDate.IsZero() {
		params.FilterEarlistFictionalDate = true
		params.EarliestFictionalDate = filter.EarliestFictionalDate.UTC()
	}
	if !filter.LatestFictionalDate.IsZero() {
		params.FilterLastestFictionalDate = true
		params.LatestFictionalDate = filter.LatestFictionalDate.UTC()
	}
	if filter.Open != nil {
		params.FilterOpen = true
		params.Open = *filter.Open
	}
	if filter.Unlisted != nil {
		params.FilterUnlisted = true
		params.Unlisted = *filter.Unlisted
	}
	if filter.Limit > 0 {
		params.LimitSize = int32(filter.Limit)
	}

	stories, err := q.SelectStories(ctx, params)
	if err != nil {
		return nil, err
	}

	targetIDs := make([]string, len(stories))
	for i, story := range stories {
		targetIDs[i] = story.ID
	}
	tags, err := q.SelectTagsByTargets(ctx, psqlcore.SelectTagsByTargetsParams{
		TargetKind: "Story",
		TargetIds:  targetIDs,
	})

	return r.stories(stories, tags), nil
}

func (r *storyRepository) Insert(ctx context.Context, story models.Story) (*models.Story, error) {
	tx, err := r.db.BeginTx(ctx, nil)
	if err != nil {
		return nil, err
	}
	defer func() { _ = tx.Rollback() }()
	q := psqlcore.New(tx)

	if !r.insertWithIDs || len(story.ID) < 8 {
		story.ID = generate.StoryID()
	}

	if story.UpdatedDate.Before(story.CreatedDate) {
		story.UpdatedDate = story.CreatedDate
	}

	err = q.InsertStory(ctx, psqlcore.InsertStoryParams{
		ID:                  story.ID,
		Author:              story.Author,
		Name:                story.Name,
		Category:            string(story.Category),
		Open:                story.Open,
		Listed:              story.Listed,
		SortByFictionalDate: story.SortByFictionalDate,
		CreatedDate:         story.CreatedDate.UTC(),
		FictionalDate:       story.FictionalDate.UTC(),
		UpdatedDate:         story.UpdatedDate.UTC(),
	})
	if err != nil {
		return nil, err
	}

	// This is inefficient, but tags are very rarely added before the story is submitted.
	err = q.SetTags(ctx, psqlcore.SetTagsParams{
		Tags:       models.EncodeTagArray(story.Tags),
		TargetKind: "Story",
		TargetID:   story.ID,
	})
	if err != nil {
		return nil, err
	}
	return &story, tx.Commit()
}

func (r *storyRepository) Update(ctx context.Context, story models.Story, update models.StoryUpdate) (*models.Story, error) {
	story.ApplyUpdate(update)

	err := psqlcore.New(r.db).UpdateStory(ctx, psqlcore.UpdateStoryParams{
		Name:                story.Name,
		Category:            string(story.Category),
		Author:              story.Author,
		Open:                story.Open,
		Listed:              story.Listed,
		FictionalDate:       story.FictionalDate.UTC(),
		UpdatedDate:         story.UpdatedDate.UTC(),
		SortByFictionalDate: story.SortByFictionalDate,
		ID:                  story.ID,
	})
	if err != nil {
		return nil, err
	}

	return &story, nil
}

func (r *storyRepository) AddTag(ctx context.Context, story models.Story, tag models.Tag) error {
	return psqlcore.New(r.db).SetTag(ctx, psqlcore.SetTagParams{
		TargetKind: "Story",
		TargetID:   story.ID,
		Tag:        tag.String(),
	})
}

func (r *storyRepository) RemoveTag(ctx context.Context, story models.Story, tag models.Tag) error {
	return psqlcore.New(r.db).ClearTag(ctx, psqlcore.ClearTagParams{
		TargetKind: "Story",
		TargetID:   story.ID,
		Tag:        tag.String(),
	})
}

func (r *storyRepository) Delete(ctx context.Context, story models.Story) error {
	tx, err := r.db.BeginTx(ctx, nil)
	if err != nil {
		return err
	}
	defer func() { _ = tx.Rollback() }()
	q := psqlcore.New(tx)

	err = q.ClearTagsByTarget(ctx, psqlcore.ClearTagsByTargetParams{
		TargetKind: "Story",
		TargetID:   story.ID,
	})
	if err != nil {
		return err
	}

	err = q.DeleteCommentsByStoryID(ctx, story.ID)
	if err != nil {
		return err
	}

	err = q.DeleteChaptersByStoryID(ctx, story.ID)
	if err != nil {
		return err
	}

	err = q.DeleteStory(ctx, story.ID)
	if err != nil {
		return err
	}

	return tx.Commit()
}

func (r *storyRepository) story(story psqlcore.Story, tags []psqlcore.CommonTag) *models.Story {
	storyTags := make([]models.Tag, 0, 8)
	for _, tag := range tags {
		if tag.TargetKind == "Story" && tag.TargetID == story.ID {
			newTag := models.Tag{}
			err := newTag.Decode(tag.Tag)
			if err != nil {
				continue
			}

			storyTags = append(storyTags, newTag)
		}
	}

	return &models.Story{
		ID:                  story.ID,
		Author:              story.Author,
		Name:                story.Name,
		Category:            models.StoryCategory(story.Category),
		Open:                story.Open,
		Listed:              story.Listed,
		Tags:                storyTags,
		CreatedDate:         story.CreatedDate,
		FictionalDate:       story.FictionalDate,
		UpdatedDate:         story.UpdatedDate,
		SortByFictionalDate: story.SortByFictionalDate,
	}
}

func (r *storyRepository) stories(stories []psqlcore.Story, tags []psqlcore.CommonTag) []*models.Story {
	results := make([]*models.Story, 0, len(stories))
	for _, story := range stories {
		results = append(results, r.story(story, tags))
	}

	return results
}