package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/evanw/esbuild/pkg/api"
	"github.com/trading-peter/gowebbuild/fsutils"
	"gopkg.in/yaml.v3"
)

func cfgToESBuildCfg(cfg options) api.BuildOptions {
	buildOptions := api.BuildOptions{
		EntryPoints: cfg.ESBuild.EntryPoints,
		Outdir:      cfg.ESBuild.Outdir,
		Outfile:     cfg.ESBuild.Outfile,
		Outbase:     cfg.ESBuild.Outbase,
		Sourcemap:   api.SourceMap(cfg.ESBuild.Sourcemap),
		Format:      api.Format(cfg.ESBuild.Format),
		Splitting:   cfg.ESBuild.Splitting,
		Platform:    api.Platform(cfg.ESBuild.Platform),
		Bundle:      cfg.ESBuild.Bundle,
		Write:       cfg.ESBuild.Write,
		LogLevel:    api.LogLevel(cfg.ESBuild.LogLevel),
	}

	// Set target if specified, otherwise default to modern ES for decorator support
	if cfg.ESBuild.Target > 0 {
		buildOptions.Target = api.Target(cfg.ESBuild.Target)
	} else {
		buildOptions.Target = api.ES2022
	}

	return buildOptions
}

type options struct {
	Extends string `yaml:"extends"` // inherit from the first profile of the referenced config file
	ESBuild struct {
		EntryPoints        []string `yaml:"entryPoints"`
		ExcludeEntryPoints []string `yaml:"excludeEntryPoints"`
		Outdir             string   `yaml:"outdir"`
		Outbase            string   `yaml:"outbase"`
		Outfile            string   `yaml:"outfile"`
		Sourcemap          int      `yaml:"sourcemap"`
		Format             int      `yaml:"format"`
		Splitting          bool     `yaml:"splitting"`
		Platform           int      `yaml:"platform"`
		Bundle             bool     `yaml:"bundle"`
		Write              bool     `yaml:"write"`
		LogLevel           int      `yaml:"logLevel"`
		Target             int      `yaml:"target"`
		PurgeBeforeBuild   bool     `yaml:"purgeBeforeBuild"`
	} `yaml:"esbuild"`
	Watch struct {
		Paths            []string `yaml:"paths"`
		Exclude          []string `yaml:"exclude"`
		InjectLiveReload string   `yaml:"injectLiveReload"`
		SkipCSPInject    bool     `yaml:"skipCSPInject"`
	}
	Serve struct {
		Path string `yaml:"path"`
		Port int    `yaml:"port"`
	} `yaml:"serve"`
	Copy []struct {
		Src  string `yaml:"src"`
		Dest string `yaml:"dest"`
	} `yaml:"copy"`
	Download []struct {
		Url  string `yaml:"url"`
		Dest string `yaml:"dest"`
	} `yaml:"download"`
	Replace []struct {
		Pattern string `yaml:"pattern"`
		Search  string `yaml:"search"`
		Replace string `yaml:"replace"`
	} `yaml:"replace"`
	ContentSwap []struct {
		File        string `yaml:"file"`
		ReplaceWith string `yaml:"replaceWith"`
	} `yaml:"contentSwap"`
	Link struct {
		From string `yaml:"from"`
		To   string `yaml:"to"`
	} `yaml:"link"`
	ProductionBuildOptions struct {
		CmdPostBuild string `yaml:"cmdPostBuild"`
	} `yaml:"productionBuildOptions"`
	NpmProxy struct {
		Overrides []NpmProxyOverride
	} `yaml:"npm_proxy"`
}

type NpmProxyOverride struct {
	Namespace   string `yaml:"namespace"`
	Upstream    string `yaml:"upstream"`
	PackageRoot string `yaml:"packageRoot"`
}

func readCfg(cfgPath string) []options {
	if filepath.Ext(cfgPath) == ".json" {
		jsonOpts := readJsonCfg(cfgPath)

		data, err := yaml.Marshal(jsonOpts)
		if err != nil {
			fmt.Printf("%+v\n", err)
			os.Exit(1)
		}

		yamlPath := strings.TrimSuffix(cfgPath, ".json") + ".yaml"

		err = os.WriteFile(yamlPath, data, 0755)
		if err != nil {
			fmt.Printf("%+v\n", err)
			os.Exit(1)
		}

		cfgPath = yamlPath
	}

	profiles := readCfgFile(cfgPath, map[string]bool{})

	// Path resolution and entry point filtering run once, after all extends
	// chains are merged, so de-duplication compares like with like and
	// patterns match the same shape as the entries.
	for i := range profiles {
		processPaths(&profiles[i])
		filterEntryPoints(&profiles[i])
	}

	return profiles
}

// readCfgFile loads a config file and resolves `extends` chains. A profile
// may declare `extends: <path>`; the first profile of the referenced file is
// merged underneath it (scalars: overlay wins when set, slices: concatenated
// base-first and de-duplicated). Chains are resolved recursively; visiting
// guards against inheritance cycles.
func readCfgFile(cfgPath string, visiting map[string]bool) []options {
	absPath, err := filepath.Abs(cfgPath)
	if err != nil {
		fmt.Printf("%+v\n", err)
		os.Exit(1)
	}

	if visiting[absPath] {
		fmt.Printf("extends cycle detected at %s\n", absPath)
		os.Exit(1)
	}
	visiting[absPath] = true
	defer delete(visiting, absPath)

	cfgContent, err := os.ReadFile(cfgPath)

	if err != nil {
		fmt.Printf("%+v\n", err)
		os.Exit(1)
	}

	optsSetups := []options{}

	err = yaml.Unmarshal(cfgContent, &optsSetups)
	if err != nil {
		opt := options{}
		err = yaml.Unmarshal(cfgContent, &opt)
		if err != nil {
			fmt.Printf("%+v\n", err)
			os.Exit(1)
		}

		optsSetups = append(optsSetups, opt)
	}

	cfgDir := filepath.Dir(cfgPath)

	for i := range optsSetups {
		base := strings.TrimSpace(optsSetups[i].Extends)

		if base == "" {
			continue
		}

		if !filepath.IsAbs(base) {
			base = filepath.Join(cfgDir, base)
		}

		baseProfiles := readCfgFile(base, visiting)

		if len(baseProfiles) == 0 {
			fmt.Printf("extends target %s contains no profiles\n", base)
			os.Exit(1)
		}

		optsSetups[i] = mergeOptions(baseProfiles[0], optsSetups[i])
	}

	return optsSetups
}

func readJsonCfg(cfgPath string) []options {
	cfgContent, err := os.ReadFile(cfgPath)

	if err != nil {
		fmt.Printf("%+v\n", err)
		os.Exit(1)
	}

	optsSetups := []options{}

	err = json.Unmarshal(cfgContent, &optsSetups)
	if err != nil {
		opt := options{}
		err = json.Unmarshal(cfgContent, &opt)
		if err != nil {
			fmt.Printf("%+v\n", err)
			os.Exit(1)
		}

		optsSetups = append(optsSetups, opt)
	}

	return optsSetups
}

func processPaths(opts *options) {
	// ESBuild paths
	for i, entry := range opts.ESBuild.EntryPoints {
		opts.ESBuild.EntryPoints[i] = fsutils.ResolvePath(entry)
	}

	for i, entry := range opts.ESBuild.ExcludeEntryPoints {
		opts.ESBuild.ExcludeEntryPoints[i] = fsutils.ResolvePath(entry)
	}
	opts.ESBuild.Outdir = fsutils.ResolvePath(opts.ESBuild.Outdir)
	opts.ESBuild.Outfile = fsutils.ResolvePath(opts.ESBuild.Outfile)

	// Watch paths
	for i, path := range opts.Watch.Paths {
		opts.Watch.Paths[i] = fsutils.ResolvePath(path)
	}

	for i, path := range opts.Watch.Exclude {
		opts.Watch.Exclude[i] = fsutils.ResolvePath(path)
	}

	// opts.Watch.Inject = fsutils.ResolvePath(opts.Watch.Inject)

	// Serve path
	opts.Serve.Path = fsutils.ResolvePath(opts.Serve.Path)

	// Copy paths
	for i := range opts.Copy {
		opts.Copy[i].Src = fsutils.ResolvePath(opts.Copy[i].Src)
		opts.Copy[i].Dest = fsutils.ResolvePath(opts.Copy[i].Dest)
	}

	// Download paths
	for i := range opts.Download {
		opts.Download[i].Dest = fsutils.ResolvePath(opts.Download[i].Dest)
	}

	// Content swap paths
	for i := range opts.ContentSwap {
		opts.ContentSwap[i].File = fsutils.ResolvePath(opts.ContentSwap[i].File)
		opts.ContentSwap[i].ReplaceWith = fsutils.ResolvePath(opts.ContentSwap[i].ReplaceWith)
	}

	// Link paths
	opts.Link.From = fsutils.ResolvePath(opts.Link.From)
	opts.Link.To = fsutils.ResolvePath(opts.Link.To)

	// Npm proxy paths
	for i := range opts.NpmProxy.Overrides {
		opts.NpmProxy.Overrides[i].PackageRoot = fsutils.ResolvePath(opts.NpmProxy.Overrides[i].PackageRoot)
	}
}