package store

import (
	"context"
	"fmt"

	"github.com/google/uuid"

	"git.warky.dev/wdevs/amcs/internal/generatedmodels"
	thoughttypes "git.warky.dev/wdevs/amcs/internal/types"
)

// LinkThoughtLearning creates or updates an association between a thought (by GUID) and a learning (by numeric ID).
// If the pair already exists, the relation label is updated.
func (db *DB) LinkThoughtLearning(ctx context.Context, thoughtGUID uuid.UUID, learningID int64, relation string) error {
	_, err := db.pool.Exec(ctx, `
		insert into thought_learning_links (thought_id, learning_id, relation)
		select t.id, $2, $3
		from thoughts t
		where t.guid = $1
		on conflict (thought_id, learning_id) do update set relation = excluded.relation
	`, thoughtGUID, learningID, relation)
	if err != nil {
		return fmt.Errorf("link thought learning: %w", err)
	}
	return nil
}

// UnlinkThoughtLearning removes the association between a thought (by GUID) and a learning (by numeric ID).
func (db *DB) UnlinkThoughtLearning(ctx context.Context, thoughtGUID uuid.UUID, learningID int64) error {
	_, err := db.pool.Exec(ctx, `
		delete from thought_learning_links
		where thought_id = (select id from thoughts where guid = $1)
		  and learning_id = $2
	`, thoughtGUID, learningID)
	if err != nil {
		return fmt.Errorf("unlink thought learning: %w", err)
	}
	return nil
}

// GetLinkedLearnings returns all learnings explicitly associated with a thought (by GUID).
func (db *DB) GetLinkedLearnings(ctx context.Context, thoughtGUID uuid.UUID) ([]thoughttypes.LinkedLearning, error) {
	rows, err := db.pool.Query(ctx, `
		select l.id, l.guid, l.summary, l.details, l.category, l.area, l.status, l.priority, l.confidence,
		       l.action_required, l.source_type, l.source_ref, l.project_id, l.related_thought_id,
		       l.related_skill_id, l.reviewed_by, l.reviewed_at, l.duplicate_of_learning_id,
		       l.supersedes_learning_id, l.tags::text[], l.created_at, l.updated_at,
		       tll.relation, tll.created_at as linked_at
		from thought_learning_links tll
		join learnings l on l.id = tll.learning_id
		where tll.thought_id = (select id from thoughts where guid = $1)
		order by tll.created_at desc
	`, thoughtGUID)
	if err != nil {
		return nil, fmt.Errorf("query linked learnings: %w", err)
	}
	defer rows.Close()

	items := make([]thoughttypes.LinkedLearning, 0)
	for rows.Next() {
		var tags []string
		var linked thoughttypes.LinkedLearning
		var m generatedmodels.ModelPublicLearnings

		if err := rows.Scan(
			&m.ID,
			&m.GUID,
			&m.Summary,
			&m.Details,
			&m.Category,
			&m.Area,
			&m.Status,
			&m.Priority,
			&m.Confidence,
			&m.ActionRequired,
			&m.SourceType,
			&m.SourceRef,
			&m.ProjectID,
			&m.RelatedThoughtID,
			&m.RelatedSkillID,
			&m.ReviewedBy,
			&m.ReviewedAt,
			&m.DuplicateOfLearningID,
			&m.SupersedesLearningID,
			&tags,
			&m.CreatedAt,
			&m.UpdatedAt,
			&linked.Relation,
			&linked.CreatedAt,
		); err != nil {
			return nil, fmt.Errorf("scan linked learning: %w", err)
		}
		linked.Learning = learningFromModel(m, tags)
		items = append(items, linked)
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("iterate linked learnings: %w", err)
	}
	return items, nil
}

// GetLinkedThoughtsForLearning returns all thoughts explicitly associated with a learning (by numeric ID).
func (db *DB) GetLinkedThoughtsForLearning(ctx context.Context, learningID int64) ([]thoughttypes.LinkedLearningThought, error) {
	rows, err := db.pool.Query(ctx, `
		select t.id, t.guid, t.content, t.metadata, t.project_id, t.archived_at, t.created_at, t.updated_at,
		       tll.relation, tll.created_at as linked_at
		from thought_learning_links tll
		join thoughts t on t.id = tll.thought_id
		where tll.learning_id = $1
		order by tll.created_at desc
	`, learningID)
	if err != nil {
		return nil, fmt.Errorf("query linked thoughts for learning: %w", err)
	}
	defer rows.Close()

	items := make([]thoughttypes.LinkedLearningThought, 0)
	for rows.Next() {
		var linked thoughttypes.LinkedLearningThought
		var m generatedmodels.ModelPublicThoughts

		if err := rows.Scan(
			&m.ID,
			&m.GUID,
			&m.Content,
			&m.Metadata,
			&m.ProjectID,
			&m.ArchivedAt,
			&m.CreatedAt,
			&m.UpdatedAt,
			&linked.Relation,
			&linked.CreatedAt,
		); err != nil {
			return nil, fmt.Errorf("scan linked thought for learning: %w", err)
		}
		thought, err := thoughtFromModel(m)
		if err != nil {
			return nil, fmt.Errorf("map linked thought for learning: %w", err)
		}
		linked.Thought = thought
		items = append(items, linked)
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("iterate linked thoughts for learning: %w", err)
	}
	return items, nil
}