package models

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	cairnapi "github.com/mattnite/cairn/internal/api"
	"gorm.io/gorm"
)

type CreateTargetParams struct {
	RepositoryID uint
	Name         string
	Type         string
	Tags         json.RawMessage
	Metadata     json.RawMessage
}

func GetOrCreateTarget(ctx context.Context, db *gorm.DB, p CreateTargetParams) (*cairnapi.Target, error) {
	if p.Tags == nil {
		p.Tags = json.RawMessage("{}")
	}
	if p.Metadata == nil {
		p.Metadata = json.RawMessage("{}")
	}

	target := &Target{}
	err := db.WithContext(ctx).
		Where("repository_id = ? AND name = ?", p.RepositoryID, p.Name).
		First(target).Error

	if err == gorm.ErrRecordNotFound {
		target = &Target{
			RepositoryID: p.RepositoryID,
			Name:         p.Name,
			Type:         p.Type,
			Tags:         p.Tags,
			Metadata:     p.Metadata,
		}
		if err := db.WithContext(ctx).Create(target).Error; err != nil {
			return nil, fmt.Errorf("creating target: %w", err)
		}
	} else if err != nil {
		return nil, fmt.Errorf("querying target: %w", err)
	}

	return enrichTarget(ctx, db, *target)
}

func GetTarget(ctx context.Context, db *gorm.DB, id uint) (*cairnapi.Target, error) {
	target := &Target{}
	if err := db.WithContext(ctx).First(target, id).Error; err != nil {
		return nil, fmt.Errorf("getting target: %w", err)
	}
	return enrichTarget(ctx, db, *target)
}

func ListTargets(ctx context.Context, db *gorm.DB, repoID *uint, limit, offset int) ([]cairnapi.Target, int64, error) {
	if limit <= 0 {
		limit = 50
	}

	query := db.WithContext(ctx).Model(&Target{})
	if repoID != nil {
		query = query.Where("repository_id = ?", *repoID)
	}

	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, fmt.Errorf("counting targets: %w", err)
	}

	var dbTargets []Target
	if err := query.Order("updated_at DESC").Limit(limit).Offset(offset).Find(&dbTargets).Error; err != nil {
		return nil, 0, fmt.Errorf("listing targets: %w", err)
	}

	targets := make([]cairnapi.Target, 0, len(dbTargets))
	for _, m := range dbTargets {
		t, err := enrichTarget(ctx, db, m)
		if err != nil {
			return nil, 0, err
		}
		targets = append(targets, *t)
	}

	return targets, total, nil
}

func enrichTarget(ctx context.Context, db *gorm.DB, model Target) (*cairnapi.Target, error) {
	repo := &Repository{}
	if err := db.WithContext(ctx).First(repo, model.RepositoryID).Error; err != nil {
		return nil, fmt.Errorf("loading target repository: %w", err)
	}

	var runCount int64
	if err := db.WithContext(ctx).Model(&Run{}).Where("target_id = ?", model.ID).Count(&runCount).Error; err != nil {
		return nil, fmt.Errorf("counting target runs: %w", err)
	}

	var corpusCount int64
	if err := db.WithContext(ctx).Model(&CorpusEntry{}).Where("target_id = ?", model.ID).Count(&corpusCount).Error; err != nil {
		return nil, fmt.Errorf("counting target corpus: %w", err)
	}

	t := targetFromModel(model)
	t.RepoName = repo.Name
	t.RunCount = runCount
	t.CorpusCount = corpusCount
	return &t, nil
}

func targetFromModel(m Target) cairnapi.Target {
	return cairnapi.Target{
		ID:           m.ID,
		RepositoryID: m.RepositoryID,
		Name:         m.Name,
		Type:         m.Type,
		Tags:         m.Tags,
		Metadata:     m.Metadata,
		CreatedAt:    m.CreatedAt,
		UpdatedAt:    m.UpdatedAt,
	}
}

// Run functions

func CreateRun(ctx context.Context, db *gorm.DB, targetID, commitID uint) (*cairnapi.Run, error) {
	run := &Run{
		TargetID:  targetID,
		CommitID:  commitID,
		Status:    "running",
		StartedAt: time.Now(),
		Tags:      json.RawMessage("{}"),
		Metadata:  json.RawMessage("{}"),
	}

	if err := db.WithContext(ctx).Create(run).Error; err != nil {
		return nil, fmt.Errorf("creating run: %w", err)
	}
	return enrichRun(ctx, db, *run)
}

func FinishRun(ctx context.Context, db *gorm.DB, id uint) error {
	now := time.Now()
	if err := db.WithContext(ctx).Model(&Run{}).Where("id = ?", id).Updates(map[string]any{
		"status":      "finished",
		"finished_at": now,
	}).Error; err != nil {
		return fmt.Errorf("finishing run: %w", err)
	}
	return nil
}

func GetRun(ctx context.Context, db *gorm.DB, id uint) (*cairnapi.Run, error) {
	run := &Run{}
	if err := db.WithContext(ctx).First(run, id).Error; err != nil {
		return nil, fmt.Errorf("getting run: %w", err)
	}
	return enrichRun(ctx, db, *run)
}

func ListRuns(ctx context.Context, db *gorm.DB, targetID *uint, limit, offset int) ([]cairnapi.Run, int64, error) {
	if limit <= 0 {
		limit = 50
	}

	query := db.WithContext(ctx).Model(&Run{})
	if targetID != nil {
		query = query.Where("target_id = ?", *targetID)
	}

	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, fmt.Errorf("counting runs: %w", err)
	}

	var dbRuns []Run
	if err := query.Order("created_at DESC").Limit(limit).Offset(offset).Find(&dbRuns).Error; err != nil {
		return nil, 0, fmt.Errorf("listing runs: %w", err)
	}

	runs := make([]cairnapi.Run, 0, len(dbRuns))
	for _, m := range dbRuns {
		r, err := enrichRun(ctx, db, m)
		if err != nil {
			return nil, 0, err
		}
		runs = append(runs, *r)
	}

	return runs, total, nil
}

func enrichRun(ctx context.Context, db *gorm.DB, model Run) (*cairnapi.Run, error) {
	target := &Target{}
	if err := db.WithContext(ctx).First(target, model.TargetID).Error; err != nil {
		return nil, fmt.Errorf("loading run target: %w", err)
	}

	repo := &Repository{}
	if err := db.WithContext(ctx).First(repo, target.RepositoryID).Error; err != nil {
		return nil, fmt.Errorf("loading run repository: %w", err)
	}

	commit := &Commit{}
	if err := db.WithContext(ctx).First(commit, model.CommitID).Error; err != nil {
		return nil, fmt.Errorf("loading run commit: %w", err)
	}

	var artifactCount int64
	_ = db.WithContext(ctx).Model(&Artifact{}).Where("run_id = ?", model.ID).Count(&artifactCount).Error

	r := runFromModel(model)
	r.TargetName = target.Name
	r.RepoName = repo.Name
	r.CommitSHA = commit.SHA
	r.ArtifactCount = artifactCount
	return &r, nil
}

func runFromModel(m Run) cairnapi.Run {
	return cairnapi.Run{
		ID:         m.ID,
		TargetID:   m.TargetID,
		CommitID:   m.CommitID,
		Status:     m.Status,
		StartedAt:  m.StartedAt,
		FinishedAt: m.FinishedAt,
		Tags:       m.Tags,
		Metadata:   m.Metadata,
		CreatedAt:  m.CreatedAt,
	}
}

// Corpus functions

type CreateCorpusEntryParams struct {
	TargetID    uint
	RunID       *uint
	BlobKey     string
	BlobSize    int64
	Fingerprint *string
}

func CreateCorpusEntry(ctx context.Context, db *gorm.DB, p CreateCorpusEntryParams) (*cairnapi.CorpusEntry, error) {
	entry := &CorpusEntry{
		TargetID:    p.TargetID,
		RunID:       p.RunID,
		BlobKey:     p.BlobKey,
		BlobSize:    p.BlobSize,
		Fingerprint: p.Fingerprint,
	}

	if err := db.WithContext(ctx).Create(entry).Error; err != nil {
		return nil, fmt.Errorf("creating corpus entry: %w", err)
	}

	return corpusEntryToAPI(*entry), nil
}

func ListCorpusEntries(ctx context.Context, db *gorm.DB, targetID uint, limit, offset int) ([]cairnapi.CorpusEntry, int64, error) {
	if limit <= 0 {
		limit = 1000
	}

	query := db.WithContext(ctx).Model(&CorpusEntry{}).Where("target_id = ?", targetID)

	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, fmt.Errorf("counting corpus entries: %w", err)
	}

	var dbEntries []CorpusEntry
	if err := query.Order("created_at DESC").Limit(limit).Offset(offset).Find(&dbEntries).Error; err != nil {
		return nil, 0, fmt.Errorf("listing corpus entries: %w", err)
	}

	entries := make([]cairnapi.CorpusEntry, 0, len(dbEntries))
	for _, e := range dbEntries {
		entries = append(entries, *corpusEntryToAPI(e))
	}

	return entries, total, nil
}

func corpusEntryToAPI(m CorpusEntry) *cairnapi.CorpusEntry {
	return &cairnapi.CorpusEntry{
		ID:          m.ID,
		TargetID:    m.TargetID,
		RunID:       m.RunID,
		BlobKey:     m.BlobKey,
		BlobSize:    m.BlobSize,
		Fingerprint: m.Fingerprint,
		CreatedAt:   m.CreatedAt,
	}
}