package api

import (
	"context"
	"fmt"

	"github.com/tigorlazuardi/bluemage/go/gen/jet/model"
	"github.com/tigorlazuardi/bluemage/go/pkg/errs"
	"github.com/tigorlazuardi/bluemage/go/pkg/telemetry"

	. "github.com/go-jet/jet/v2/sqlite"
	. "github.com/tigorlazuardi/bluemage/go/gen/jet/table"
)

type ImageListRequest struct {
	Subreddits []string
	Devices    []string
	Limit      int64
	After      int64
	Before     int64
	OrderBy    string
	Sort       Sort
	Search     string
	NSFW       *bool
	Blacklist  *bool
}

// CREATE VIRTUAL TABLE images_fts5 USING fts5(
//
//	post_author,
//	post_title,
//	post_name,
//	image_relative_path,
//	post_url,
//	post_author_url,
//	content='images',
//	content_rowid='id'
//
// );
//
// matching list:
//
//   - Author's name
//   - Post Title
//   - Post ID
//   - Author's ID
//   - Image filename (url path suffix to get this image from web browser)
//   - Image original url
//   - Post url
//   - Author's url
var imagesFTSBM25 = fmt.Sprintf("bm25(%s, 25, 20, 10, 5, 3, 3)", ImagesFts5.TableName())

func (request ImageListRequest) Statement() Statement {
	queriedImages := CTE("queried_images")

	return WITH(
		queriedImages.AS(request.SelectStatement()),
	)(
		SELECT(queriedImages.AllColumns()).
			FROM(queriedImages).
			ORDER_BY(
				Images.Device.ASC(),
				Images.Subreddit.ASC(),
			),
	)
}

func (request ImageListRequest) SelectStatement() SelectStatement {
	cond := request.WhereExpression()
	from := Images

	if len(request.Search) > 0 {
		cond.AND(ImagesFts5.ImagesFts5.EQ(String(request.Search)))
		from.INNER_JOIN(ImagesFts5, Images.PostName.EQ(ImagesFts5.PostName))
		stmt := SELECT(Images.AllColumns).FROM(from).WHERE(cond)
		if request.Limit > 0 {
			stmt.LIMIT(request.Limit)
		}
		return stmt.ORDER_BY(RawString(imagesFTSBM25).DESC())
	}
	stmt := SELECT(Images.AllColumns).FROM(from).WHERE(cond)
	if request.Limit > 0 {
		stmt.LIMIT(request.Limit)
	}

	if request.OrderBy == "" {
		return stmt.ORDER_BY(Images.CreatedAt.DESC())
	}

	orderBy := StringColumn(request.OrderBy)
	if request.Sort == SortDesc {
		return stmt.ORDER_BY(orderBy.DESC())
	}
	return stmt.ORDER_BY(orderBy.ASC())
}

func (request ImageListRequest) WhereExpression() BoolExpression {
	cond := Bool(true)
	if len(request.Devices) > 0 {
		cond.AND(Images.Device.IN(stringSliceExpressions(request.Devices)...))
	}

	if len(request.Subreddits) > 0 {
		cond.AND(Images.Subreddit.IN(stringSliceExpressions(request.Subreddits)...))
	}

	if request.NSFW != nil {
		n := *request.NSFW
		if n {
			cond.AND(Images.Nsfw.EQ(Int(1)))
		} else {
			cond.AND(Images.Nsfw.EQ(Int(0)))
		}
	}

	if request.Blacklist != nil {
		b := *request.Blacklist
		if b {
			cond.AND(Images.Blacklisted.EQ(Int(1)))
		} else {
			cond.AND(Images.Blacklisted.EQ(Int(0)))
		}
	}

	if request.After > 0 {
		cond.AND(Images.CreatedAt.LT_EQ(Int(request.After)))
	}

	if request.Before > 0 {
		cond.AND(Images.CreatedAt.GT_EQ(Int(request.Before)))
	}
	return cond
}

// ImageList list images by request.
//
// Results are always grouped by device then grouped by subreddit after sorting.
func (api *API) ImageList(ctx context.Context, request ImageListRequest) (images []model.Images, err error) {
	ctx, span := tracer.Start(ctx, "ImageList")
	defer func() { telemetry.EndWithStatus(span, err) }()

	stmt := request.Statement()
	if err := stmt.QueryContext(ctx, api.DB, &images); err != nil {
		return images, errs.Wrapw(err, "failed to list images",
			"request", request,
			"query", stmt.DebugSql(),
		)
	}

	return images, err
}

func stringSliceExpressions(s []string) []Expression {
	var expr []Expression
	if s != nil {
		expr = make([]Expression, len(s))
		for i, str := range s {
			expr[i] = String(str)
		}
	}
	return expr
}