// Copyright 2022 Woodpecker Authors
// Copyright 2018 Drone.IO Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package stepbuilder

import (
	"fmt"
	"path/filepath"
	"strings"

	"github.com/oklog/ulid/v2"
	"github.com/rs/zerolog/log"
	"go.uber.org/multierr"

	backend_types "go.woodpecker-ci.org/woodpecker/v2/pipeline/backend/types"
	pipeline_errors "go.woodpecker-ci.org/woodpecker/v2/pipeline/errors"
	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/metadata"
	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml"
	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml/compiler"
	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml/linter"
	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml/matrix"
	yaml_types "go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml/types"
	"go.woodpecker-ci.org/woodpecker/v2/server"
	forge_types "go.woodpecker-ci.org/woodpecker/v2/server/forge/types"
	"go.woodpecker-ci.org/woodpecker/v2/server/model"
)

// StepBuilder Takes the hook data and the yaml and returns in internal data model
type StepBuilder struct {
	Repo      *model.Repo
	Curr      *model.Pipeline
	Last      *model.Pipeline
	Netrc     *model.Netrc
	Secs      []*model.Secret
	Regs      []*model.Registry
	Host      string
	Yamls     []*forge_types.FileMeta
	Envs      map[string]string
	Forge     metadata.ServerForge
	ProxyOpts compiler.ProxyOptions
}

type Item struct {
	Workflow  *model.Workflow
	Labels    map[string]string
	DependsOn []string
	RunsOn    []string
	Config    *backend_types.Config
}

func (b *StepBuilder) Build() (items []*Item, errorsAndWarnings error) {
	b.Yamls = forge_types.SortByName(b.Yamls)

	pidSequence := 1

	for _, y := range b.Yamls {
		// matrix axes
		axes, err := matrix.ParseString(string(y.Data))
		if err != nil {
			return nil, err
		}
		if len(axes) == 0 {
			axes = append(axes, matrix.Axis{})
		}

		for i, axis := range axes {
			workflow := &model.Workflow{
				PID:     pidSequence,
				State:   model.StatusPending,
				Environ: axis,
				Name:    SanitizePath(y.Name),
			}
			if len(axes) > 1 {
				workflow.AxisID = i + 1
			}
			item, err := b.genItemForWorkflow(workflow, axis, string(y.Data))
			if err != nil && pipeline_errors.HasBlockingErrors(err) {
				return nil, err
			} else if err != nil {
				errorsAndWarnings = multierr.Append(errorsAndWarnings, err)
			}

			if item == nil {
				continue
			}
			items = append(items, item)
			pidSequence++
		}

		// TODO: add summary workflow that send status back based on workflows generated by matrix function
		// depend on https://github.com/woodpecker-ci/woodpecker/issues/778
	}

	items = filterItemsWithMissingDependencies(items)

	// check if at least one step can start if slice is not empty
	if len(items) > 0 && !stepListContainsItemsToRun(items) {
		return nil, fmt.Errorf("pipeline has no steps to run")
	}

	return items, errorsAndWarnings
}

func (b *StepBuilder) genItemForWorkflow(workflow *model.Workflow, axis matrix.Axis, data string) (item *Item, errorsAndWarnings error) {
	workflowMetadata := MetadataFromStruct(b.Forge, b.Repo, b.Curr, b.Last, workflow, b.Host)
	environ := b.environmentVariables(workflowMetadata, axis)

	// add global environment variables for substituting
	for k, v := range b.Envs {
		if _, exists := environ[k]; exists {
			// don't override existing values
			continue
		}
		environ[k] = v
	}

	// substitute vars
	substituted, err := metadata.EnvVarSubst(data, environ)
	if err != nil {
		return nil, multierr.Append(errorsAndWarnings, err)
	}

	// parse yaml pipeline
	parsed, err := yaml.ParseString(substituted)
	if err != nil {
		return nil, &pipeline_errors.PipelineError{Message: err.Error(), Type: pipeline_errors.PipelineErrorTypeCompiler}
	}

	// lint pipeline
	errorsAndWarnings = multierr.Append(errorsAndWarnings, linter.New(
		linter.WithTrusted(b.Repo.IsTrusted),
	).Lint([]*linter.WorkflowConfig{{
		Workflow:  parsed,
		File:      workflow.Name,
		RawConfig: data,
	}}))
	if pipeline_errors.HasBlockingErrors(errorsAndWarnings) {
		return nil, errorsAndWarnings
	}

	// checking if filtered.
	if match, err := parsed.When.Match(workflowMetadata, true, environ); !match && err == nil {
		log.Debug().Str("pipeline", workflow.Name).Msg(
			"marked as skipped, does not match metadata",
		)
		return nil, nil
	} else if err != nil {
		log.Debug().Str("pipeline", workflow.Name).Msg(
			"pipeline config could not be parsed",
		)
		return nil, multierr.Append(errorsAndWarnings, err)
	}

	ir, err := b.toInternalRepresentation(parsed, environ, workflowMetadata, workflow.ID)
	if err != nil {
		return nil, multierr.Append(errorsAndWarnings, err)
	}

	if len(ir.Stages) == 0 {
		return nil, nil
	}

	item = &Item{
		Workflow:  workflow,
		Config:    ir,
		Labels:    parsed.Labels,
		DependsOn: parsed.DependsOn,
		RunsOn:    parsed.RunsOn,
	}
	if item.Labels == nil {
		item.Labels = map[string]string{}
	}

	return item, errorsAndWarnings
}

func stepListContainsItemsToRun(items []*Item) bool {
	for i := range items {
		if items[i].Workflow.State == model.StatusPending {
			return true
		}
	}
	return false
}

func filterItemsWithMissingDependencies(items []*Item) []*Item {
	itemsToRemove := make([]*Item, 0)

	for _, item := range items {
		for _, dep := range item.DependsOn {
			if !containsItemWithName(dep, items) {
				itemsToRemove = append(itemsToRemove, item)
			}
		}
	}

	if len(itemsToRemove) > 0 {
		filtered := make([]*Item, 0)
		for _, item := range items {
			if !containsItemWithName(item.Workflow.Name, itemsToRemove) {
				filtered = append(filtered, item)
			}
		}
		// Recursive to handle transitive deps
		return filterItemsWithMissingDependencies(filtered)
	}

	return items
}

func containsItemWithName(name string, items []*Item) bool {
	for _, item := range items {
		if name == item.Workflow.Name {
			return true
		}
	}
	return false
}

func (b *StepBuilder) environmentVariables(metadata metadata.Metadata, axis matrix.Axis) map[string]string {
	environ := metadata.Environ()
	for k, v := range axis {
		environ[k] = v
	}
	return environ
}

func (b *StepBuilder) toInternalRepresentation(parsed *yaml_types.Workflow, environ map[string]string, metadata metadata.Metadata, stepID int64) (*backend_types.Config, error) {
	var secrets []compiler.Secret
	for _, sec := range b.Secs {
		events := []string{}
		for _, event := range sec.Events {
			events = append(events, string(event))
		}

		secrets = append(secrets, compiler.Secret{
			Name:           sec.Name,
			Value:          sec.Value,
			AllowedPlugins: sec.Images,
			Events:         events,
		})
	}

	var registries []compiler.Registry
	for _, reg := range b.Regs {
		registries = append(registries, compiler.Registry{
			Hostname: reg.Address,
			Username: reg.Username,
			Password: reg.Password,
		})
	}

	return compiler.New(
		compiler.WithEnviron(environ),
		compiler.WithEnviron(b.Envs),
		// TODO: server deps should be moved into StepBuilder fields and set on StepBuilder creation
		compiler.WithEscalated(server.Config.Pipeline.Privileged...),
		compiler.WithResourceLimit(server.Config.Pipeline.Limits.MemSwapLimit, server.Config.Pipeline.Limits.MemLimit, server.Config.Pipeline.Limits.ShmSize, server.Config.Pipeline.Limits.CPUQuota, server.Config.Pipeline.Limits.CPUShares, server.Config.Pipeline.Limits.CPUSet),
		compiler.WithVolumes(server.Config.Pipeline.Volumes...),
		compiler.WithNetworks(server.Config.Pipeline.Networks...),
		compiler.WithLocal(false),
		compiler.WithOption(
			compiler.WithNetrc(
				b.Netrc.Login,
				b.Netrc.Password,
				b.Netrc.Machine,
			),
			b.Repo.IsSCMPrivate || server.Config.Pipeline.AuthenticatePublicRepos,
		),
		compiler.WithDefaultCloneImage(server.Config.Pipeline.DefaultCloneImage),
		compiler.WithRegistry(registries...),
		compiler.WithSecret(secrets...),
		compiler.WithPrefix(
			fmt.Sprintf(
				"wp_%s_%d",
				strings.ToLower(ulid.Make().String()),
				stepID,
			),
		),
		compiler.WithProxy(b.ProxyOpts),
		compiler.WithWorkspaceFromURL("/woodpecker", b.Repo.ForgeURL),
		compiler.WithMetadata(metadata),
		compiler.WithTrusted(b.Repo.IsTrusted),
		compiler.WithNetrcOnlyTrusted(b.Repo.NetrcOnlyTrusted),
	).Compile(parsed)
}

func SanitizePath(path string) string {
	path = filepath.Base(path)
	path = strings.TrimSuffix(path, ".yml")
	path = strings.TrimSuffix(path, ".yaml")
	path = strings.TrimPrefix(path, ".")
	return path
}