package coderd

import (
	"context"
	"database/sql"
	"errors"
	"net/http"

	"github.com/go-chi/chi/v5"
	"github.com/google/uuid"
	"golang.org/x/xerrors"

	"github.com/coder/coder/v2/coderd/audit"
	"github.com/coder/coder/v2/coderd/database"
	"github.com/coder/coder/v2/coderd/database/db2sdk"
	"github.com/coder/coder/v2/coderd/httpapi"
	"github.com/coder/coder/v2/coderd/httpmw"
	"github.com/coder/coder/v2/codersdk"
)

const (
	userSecretNameField     = "name"
	userSecretValueField    = "value"
	userSecretEnvNameField  = "env_name"
	userSecretFilePathField = "file_path"
)

// @Summary Create a new user secret
// @ID create-a-new-user-secret
// @Security CoderSessionToken
// @Accept json
// @Produce json
// @Tags Secrets
// @Param user path string true "User ID, username, or me"
// @Param request body codersdk.CreateUserSecretRequest true "Create secret request"
// @Success 201 {object} codersdk.UserSecret
// @Router /api/v2/users/{user}/secrets [post]
func (api *API) postUserSecret(rw http.ResponseWriter, r *http.Request) {
	var (
		ctx               = r.Context()
		user              = httpmw.UserParam(r)
		auditor           = api.Auditor.Load()
		aReq, commitAudit = audit.InitRequest[database.UserSecret](rw, &audit.RequestParams{
			Audit:   *auditor,
			Log:     api.Logger,
			Request: r,
			Action:  database.AuditActionCreate,
		})
	)
	defer commitAudit()

	var req codersdk.CreateUserSecretRequest
	if !httpapi.Read(ctx, rw, r, &req) {
		return
	}

	if validations := createUserSecretValidationErrors(req); len(validations) > 0 {
		writeUserSecretValidationErrors(ctx, rw, http.StatusBadRequest, validations)
		return
	}

	secret, err := api.Database.CreateUserSecret(ctx, database.CreateUserSecretParams{
		ID:          uuid.New(),
		UserID:      user.ID,
		Name:        req.Name,
		Description: req.Description,
		Value:       req.Value,
		ValueKeyID:  sql.NullString{},
		EnvName:     req.EnvName,
		FilePath:    req.FilePath,
	})
	if err != nil {
		if validations := userSecretConflictValidationErrors(err); len(validations) > 0 {
			writeUserSecretValidationErrors(ctx, rw, http.StatusConflict, validations)
			return
		}
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Internal error creating secret.",
			Detail:  err.Error(),
		})
		return
	}
	aReq.New = secret

	httpapi.Write(ctx, rw, http.StatusCreated, db2sdk.UserSecretFromFull(secret))
}

// @Summary List user secrets
// @ID list-user-secrets
// @Security CoderSessionToken
// @Produce json
// @Tags Secrets
// @Param user path string true "User ID, username, or me"
// @Success 200 {array} codersdk.UserSecret
// @Router /api/v2/users/{user}/secrets [get]
func (api *API) getUserSecrets(rw http.ResponseWriter, r *http.Request) { //nolint:revive // Method name matches route.
	ctx := r.Context()
	user := httpmw.UserParam(r)

	secrets, err := api.Database.ListUserSecrets(ctx, user.ID)
	if err != nil {
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Internal error listing secrets.",
			Detail:  err.Error(),
		})
		return
	}

	httpapi.Write(ctx, rw, http.StatusOK, db2sdk.UserSecrets(secrets))
}

// @Summary Get a user secret by name
// @ID get-a-user-secret-by-name
// @Security CoderSessionToken
// @Produce json
// @Tags Secrets
// @Param user path string true "User ID, username, or me"
// @Param name path string true "Secret name"
// @Success 200 {object} codersdk.UserSecret
// @Router /api/v2/users/{user}/secrets/{name} [get]
func (api *API) getUserSecret(rw http.ResponseWriter, r *http.Request) { //nolint:revive // Method name matches route.
	ctx := r.Context()
	user := httpmw.UserParam(r)
	name := chi.URLParam(r, userSecretNameField)

	secret, err := api.Database.GetUserSecretByUserIDAndName(ctx, database.GetUserSecretByUserIDAndNameParams{
		UserID: user.ID,
		Name:   name,
	})
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			httpapi.ResourceNotFound(rw)
			return
		}
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Internal error fetching secret.",
			Detail:  err.Error(),
		})
		return
	}

	httpapi.Write(ctx, rw, http.StatusOK, db2sdk.UserSecretFromFull(secret))
}

// @Summary Update a user secret
// @ID update-a-user-secret
// @Security CoderSessionToken
// @Accept json
// @Produce json
// @Tags Secrets
// @Param user path string true "User ID, username, or me"
// @Param name path string true "Secret name"
// @Param request body codersdk.UpdateUserSecretRequest true "Update secret request"
// @Success 200 {object} codersdk.UserSecret
// @Router /api/v2/users/{user}/secrets/{name} [patch]
func (api *API) patchUserSecret(rw http.ResponseWriter, r *http.Request) {
	var (
		ctx               = r.Context()
		user              = httpmw.UserParam(r)
		name              = chi.URLParam(r, userSecretNameField)
		auditor           = api.Auditor.Load()
		aReq, commitAudit = audit.InitRequest[database.UserSecret](rw, &audit.RequestParams{
			Audit:   *auditor,
			Log:     api.Logger,
			Request: r,
			Action:  database.AuditActionWrite,
		})
	)
	defer commitAudit()

	var req codersdk.UpdateUserSecretRequest
	if !httpapi.Read(ctx, rw, r, &req) {
		return
	}

	if req.Value == nil && req.Description == nil && req.EnvName == nil && req.FilePath == nil {
		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
			Message: "At least one field must be provided.",
		})
		return
	}
	if validations := updateUserSecretValidationErrors(req); len(validations) > 0 {
		writeUserSecretValidationErrors(ctx, rw, http.StatusBadRequest, validations)
		return
	}

	params := database.UpdateUserSecretByUserIDAndNameParams{
		UserID:            user.ID,
		Name:              name,
		UpdateValue:       req.Value != nil,
		Value:             "",
		ValueKeyID:        sql.NullString{},
		UpdateDescription: req.Description != nil,
		Description:       "",
		UpdateEnvName:     req.EnvName != nil,
		EnvName:           "",
		UpdateFilePath:    req.FilePath != nil,
		FilePath:          "",
	}
	if req.Value != nil {
		params.Value = *req.Value
	}
	if req.Description != nil {
		params.Description = *req.Description
	}
	if req.EnvName != nil {
		params.EnvName = *req.EnvName
	}
	if req.FilePath != nil {
		params.FilePath = *req.FilePath
	}

	// Pre-read the secret inside a transaction so the audit diff has both an
	// "old" and "new" snapshot.
	//
	// Under read committed isolation, a concurrent writer between our SELECT
	// and our UPDATE can cause the audit diff to attribute changes to us that
	// we did not make. We accept this race to match other audit log diffs
	// (templates, workspaces, chats, etc). In practice this should be unlikely
	// to hit since a user can only modify their own secrets.
	var secret database.UserSecret
	err := api.Database.InTx(func(tx database.Store) error {
		old, err := tx.GetUserSecretByUserIDAndName(ctx, database.GetUserSecretByUserIDAndNameParams{
			UserID: user.ID,
			Name:   name,
		})
		if err != nil {
			return xerrors.Errorf("fetch user secret: %w", err)
		}
		aReq.Old = old

		updated, err := tx.UpdateUserSecretByUserIDAndName(ctx, params)
		if err != nil {
			return xerrors.Errorf("update user secret: %w", err)
		}
		secret = updated
		aReq.New = updated
		return nil
	}, nil)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			httpapi.ResourceNotFound(rw)
			return
		}
		if validations := userSecretConflictValidationErrors(err); len(validations) > 0 {
			writeUserSecretValidationErrors(ctx, rw, http.StatusConflict, validations)
			return
		}
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Internal error updating secret.",
			Detail:  err.Error(),
		})
		return
	}

	httpapi.Write(ctx, rw, http.StatusOK, db2sdk.UserSecretFromFull(secret))
}

// @Summary Delete a user secret
// @ID delete-a-user-secret
// @Security CoderSessionToken
// @Tags Secrets
// @Param user path string true "User ID, username, or me"
// @Param name path string true "Secret name"
// @Success 204
// @Router /api/v2/users/{user}/secrets/{name} [delete]
func (api *API) deleteUserSecret(rw http.ResponseWriter, r *http.Request) {
	var (
		ctx               = r.Context()
		user              = httpmw.UserParam(r)
		name              = chi.URLParam(r, userSecretNameField)
		auditor           = api.Auditor.Load()
		aReq, commitAudit = audit.InitRequest[database.UserSecret](rw, &audit.RequestParams{
			Audit:   *auditor,
			Log:     api.Logger,
			Request: r,
			Action:  database.AuditActionDelete,
		})
	)
	defer commitAudit()

	deleted, err := api.Database.DeleteUserSecretByUserIDAndName(ctx, database.DeleteUserSecretByUserIDAndNameParams{
		UserID: user.ID,
		Name:   name,
	})
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			httpapi.ResourceNotFound(rw)
			return
		}
		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
			Message: "Internal error deleting secret.",
			Detail:  err.Error(),
		})
		return
	}
	aReq.Old = deleted

	rw.WriteHeader(http.StatusNoContent)
}

func writeUserSecretValidationErrors(ctx context.Context, rw http.ResponseWriter, status int, validations []codersdk.ValidationError) {
	httpapi.Write(ctx, rw, status, codersdk.Response{
		Message:     "Validation failed.",
		Validations: validations,
	})
}

func createUserSecretValidationErrors(req codersdk.CreateUserSecretRequest) []codersdk.ValidationError {
	var validations []codersdk.ValidationError
	validations = appendUserSecretValidationError(validations, userSecretNameField, codersdk.UserSecretNameValid(req.Name))
	if req.Value == "" {
		validations = append(validations, codersdk.ValidationError{
			Field:  userSecretValueField,
			Detail: "Value is required.",
		})
	} else {
		validations = appendUserSecretValidationError(validations, userSecretValueField, codersdk.UserSecretValueValid(req.Value))
	}
	validations = appendUserSecretValidationError(validations, userSecretEnvNameField, codersdk.UserSecretEnvNameValid(req.EnvName))
	validations = appendUserSecretValidationError(validations, userSecretFilePathField, codersdk.UserSecretFilePathValid(req.FilePath))
	return validations
}

func updateUserSecretValidationErrors(req codersdk.UpdateUserSecretRequest) []codersdk.ValidationError {
	var validations []codersdk.ValidationError
	if req.Value != nil {
		validations = appendUserSecretValidationError(validations, userSecretValueField, codersdk.UserSecretValueValid(*req.Value))
	}
	if req.EnvName != nil {
		validations = appendUserSecretValidationError(validations, userSecretEnvNameField, codersdk.UserSecretEnvNameValid(*req.EnvName))
	}
	if req.FilePath != nil {
		validations = appendUserSecretValidationError(validations, userSecretFilePathField, codersdk.UserSecretFilePathValid(*req.FilePath))
	}
	return validations
}

func appendUserSecretValidationError(validations []codersdk.ValidationError, field string, err error) []codersdk.ValidationError {
	if err == nil {
		return validations
	}
	return append(validations, codersdk.ValidationError{
		Field:  field,
		Detail: err.Error(),
	})
}

func userSecretConflictValidationErrors(err error) []codersdk.ValidationError {
	switch {
	case database.IsUniqueViolation(err, database.UniqueUserSecretsUserNameIndex):
		return []codersdk.ValidationError{{
			Field:  userSecretNameField,
			Detail: "name already in use",
		}}
	case database.IsUniqueViolation(err, database.UniqueUserSecretsUserEnvNameIndex):
		return []codersdk.ValidationError{{
			Field:  userSecretEnvNameField,
			Detail: "environment variable already in use",
		}}
	case database.IsUniqueViolation(err, database.UniqueUserSecretsUserFilePathIndex):
		return []codersdk.ValidationError{{
			Field:  userSecretFilePathField,
			Detail: "file path already in use",
		}}
	default:
		return nil
	}
}