// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package secret

import (
	"context"
	"fmt"
	"strings"

	actions_model "gitea.dev/models/actions"
	"gitea.dev/models/db"
	actions_module "gitea.dev/modules/actions"
	"gitea.dev/modules/actions/jobparser"
	"gitea.dev/modules/json"
	"gitea.dev/modules/log"
	secret_module "gitea.dev/modules/secret"
	"gitea.dev/modules/setting"
	"gitea.dev/modules/timeutil"
	"gitea.dev/modules/util"

	"xorm.io/builder"
)

// Secret represents a secret
//
// It can be:
//  1. org/user level secret, OwnerID is org/user ID and RepoID is 0
//  2. repo level secret, OwnerID is 0 and RepoID is repo ID
//
// Please note that it's not acceptable to have both OwnerID and RepoID to be non-zero,
// or it will be complicated to find secrets belonging to a specific owner.
// For example, conditions like `OwnerID = 1` will also return secret {OwnerID: 1, RepoID: 1},
// but it's a repo level secret, not an org/user level secret.
// To avoid this, make it clear with {OwnerID: 0, RepoID: 1} for repo level secrets.
//
// Please note that it's not acceptable to have both OwnerID and RepoID to zero, global secrets are not supported.
// It's for security reasons, admin may be not aware of that the secrets could be stolen by any user when setting them as global.
type Secret struct {
	ID          int64
	OwnerID     int64              `xorm:"INDEX UNIQUE(owner_repo_name) NOT NULL"`
	RepoID      int64              `xorm:"INDEX UNIQUE(owner_repo_name) NOT NULL DEFAULT 0"`
	Name        string             `xorm:"UNIQUE(owner_repo_name) NOT NULL"`
	Data        string             `xorm:"LONGTEXT"` // encrypted data
	Description string             `xorm:"TEXT"`
	CreatedUnix timeutil.TimeStamp `xorm:"created NOT NULL"`
}

const (
	SecretDataMaxLength        = 65536
	SecretDescriptionMaxLength = 4096
)

// ErrSecretNotFound represents a "secret not found" error.
type ErrSecretNotFound struct {
	Name string
}

func (err ErrSecretNotFound) Error() string {
	return fmt.Sprintf("secret was not found [name: %s]", err.Name)
}

func (err ErrSecretNotFound) Unwrap() error {
	return util.ErrNotExist
}

// InsertEncryptedSecret Creates, encrypts, and validates a new secret with yet unencrypted data and insert into database
func InsertEncryptedSecret(ctx context.Context, ownerID, repoID int64, name, data, description string) (*Secret, error) {
	if ownerID != 0 && repoID != 0 {
		// It's trying to create a secret that belongs to a repository, but OwnerID has been set accidentally.
		// Remove OwnerID to avoid confusion; it's not worth returning an error here.
		ownerID = 0
	}
	if ownerID == 0 && repoID == 0 {
		return nil, fmt.Errorf("%w: ownerID and repoID cannot be both zero, global secrets are not supported", util.ErrInvalidArgument)
	}

	if len(data) > SecretDataMaxLength {
		return nil, util.NewInvalidArgumentErrorf("data too long")
	}

	description = util.TruncateRunes(description, SecretDescriptionMaxLength)

	encrypted, err := secret_module.EncryptSecret(setting.SecretKey, data)
	if err != nil {
		return nil, err
	}

	secret := &Secret{
		OwnerID:     ownerID,
		RepoID:      repoID,
		Name:        strings.ToUpper(name),
		Data:        encrypted,
		Description: description,
	}
	return secret, db.Insert(ctx, secret)
}

func init() {
	db.RegisterModel(new(Secret))
}

type FindSecretsOptions struct {
	db.ListOptions
	RepoID   int64
	OwnerID  int64 // it will be ignored if RepoID is set
	SecretID int64
	Name     string
}

func (opts FindSecretsOptions) ToConds() builder.Cond {
	cond := builder.NewCond()

	cond = cond.And(builder.Eq{"repo_id": opts.RepoID})
	if opts.RepoID != 0 { // if RepoID is set
		// ignore OwnerID and treat it as 0
		cond = cond.And(builder.Eq{"owner_id": 0})
	} else {
		cond = cond.And(builder.Eq{"owner_id": opts.OwnerID})
	}

	if opts.SecretID != 0 {
		cond = cond.And(builder.Eq{"id": opts.SecretID})
	}
	if opts.Name != "" {
		cond = cond.And(builder.Eq{"name": strings.ToUpper(opts.Name)})
	}

	return cond
}

// UpdateSecret changes org or user reop secret.
func UpdateSecret(ctx context.Context, secretID int64, data, description string) error {
	if len(data) > SecretDataMaxLength {
		return util.NewInvalidArgumentErrorf("data too long")
	}

	description = util.TruncateRunes(description, SecretDescriptionMaxLength)

	encrypted, err := secret_module.EncryptSecret(setting.SecretKey, data)
	if err != nil {
		return err
	}

	s := &Secret{
		Data:        encrypted,
		Description: description,
	}
	affected, err := db.GetEngine(ctx).ID(secretID).Cols("data", "description").Update(s)
	if affected != 1 {
		return ErrSecretNotFound{}
	}
	return err
}

func GetSecretsOfTask(ctx context.Context, task *actions_model.ActionTask) (map[string]string, error) {
	baseSecrets := map[string]string{}

	baseSecrets["GITHUB_TOKEN"] = task.Token
	baseSecrets["GITEA_TOKEN"] = task.Token

	if task.Job.Run.IsForkPullRequest && task.Job.Run.TriggerEvent != actions_module.GithubEventPullRequestTarget {
		// ignore secrets for fork pull request, except GITHUB_TOKEN and GITEA_TOKEN which are automatically generated.
		// for the tasks triggered by pull_request_target event, they could access the secrets because they will run in the context of the base branch
		// see the documentation: https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target
		return baseSecrets, nil
	}

	ownerSecrets, err := db.Find[Secret](ctx, FindSecretsOptions{OwnerID: task.Job.Run.Repo.OwnerID})
	if err != nil {
		log.Error("find secrets of owner %v: %v", task.Job.Run.Repo.OwnerID, err)
		return nil, err
	}
	repoSecrets, err := db.Find[Secret](ctx, FindSecretsOptions{RepoID: task.Job.Run.RepoID})
	if err != nil {
		log.Error("find secrets of repo %v: %v", task.Job.Run.RepoID, err)
		return nil, err
	}

	for _, secret := range append(ownerSecrets, repoSecrets...) {
		v, err := secret_module.DecryptSecret(setting.SecretKey, secret.Data)
		if err != nil {
			log.Error("Unable to decrypt Actions secret %v %q, maybe SECRET_KEY is wrong: %v", secret.ID, secret.Name, err)
			continue
		}
		baseSecrets[secret.Name] = v
	}

	return getScopedSecretsForJob(ctx, task.Job, baseSecrets)
}

// getScopedSecretsForJob walks up the caller chain (ParentJobID) and applies
// each caller's secrets policy:
//   - "secrets: inherit" passes the parent scope's secrets through unchanged.
//   - explicit mapping {alias: SOURCE} only forwards the named secrets, plus the auto-generated tokens.
//
// For top-level jobs (ParentJobID == 0) the base secrets are returned as-is.
func getScopedSecretsForJob(ctx context.Context, job *actions_model.ActionRunJob, baseSecrets map[string]string) (map[string]string, error) {
	if job.ParentJobID == 0 {
		return baseSecrets, nil
	}

	caller, err := actions_model.GetRunJobByRunAndID(ctx, job.RunID, job.ParentJobID)
	if err != nil {
		return nil, fmt.Errorf("load caller job %d: %w", job.ParentJobID, err)
	}

	parentScope, err := getScopedSecretsForJob(ctx, caller, baseSecrets)
	if err != nil {
		return nil, err
	}

	if caller.CallSecrets == jobparser.SecretsInherit {
		return parentScope, nil
	}

	// Empty or explicit-mapping path: only auto-tokens + (any) mapped aliases are exposed.
	scoped := map[string]string{
		"GITHUB_TOKEN": baseSecrets["GITHUB_TOKEN"],
		"GITEA_TOKEN":  baseSecrets["GITEA_TOKEN"],
	}
	if caller.CallSecrets == "" {
		return scoped, nil
	}
	var mapping map[string]string
	if err := json.Unmarshal([]byte(caller.CallSecrets), &mapping); err != nil {
		return nil, fmt.Errorf("decode caller %d secret map: %w", caller.ID, err)
	}
	for alias, source := range mapping {
		if v, ok := parentScope[source]; ok {
			scoped[alias] = v
			continue
		}
		// Secret names are case-insensitive in storage (uppercased).
		if v, ok := parentScope[strings.ToUpper(source)]; ok {
			scoped[alias] = v
		}
	}
	return scoped, nil
}

func CountWrongRepoLevelSecrets(ctx context.Context) (int64, error) {
	var result int64
	_, err := db.GetEngine(ctx).SQL("SELECT count(`id`) FROM `secret` WHERE `repo_id` > 0 AND `owner_id` > 0").Get(&result)
	return result, err
}

func UpdateWrongRepoLevelSecrets(ctx context.Context) (int64, error) {
	result, err := db.GetEngine(ctx).Exec("UPDATE `secret` SET `owner_id` = 0 WHERE `repo_id` > 0 AND `owner_id` > 0")
	if err != nil {
		return 0, err
	}
	return result.RowsAffected()
}
