package generate

import (
	"fmt"

	"github.com/spf13/cobra"
)

var helpSchemaCommand = &cobra.Command{
	Use:   "help-schema",
	Short: "Print a documented TOML schema to STDOUT",
	Run: func(cmd *cobra.Command, args []string) {
		fmt.Print(documentedSchema)
	},
}

func init() {
	Command.AddCommand(helpSchemaCommand)
}

const documentedSchema = `title = "Documented schema"

# limit the maximum number of series generated across all measurements
#
# series-limit: integer, optional (default: unlimited)

[[measurements]]

# name of measurement
#
# NOTE: 
# Multiple definitions of the same measurement name are allowed and
# will be merged together.
name = "cpu"

# sample: float; where 0 < sample ≤ 1.0 (default: 0.5)
#   sample a subset of the tag set
#
# sample 25% of the tags
#
sample = 0.25

# Keys for defining a tag
#
# name: string, required
#   Name of field
#
# source: array<string> or object
# 
#   A literal array of string values defines the tag values.
#
#   An object defines more complex generators. The type key determines the
#   type of generator.
#
# source types:
#
# type: "sequence" 
#   generate a sequence of tag values
#
#       format: string
#           a format string for the values (default: "value%s")
#       start: int (default: 0)
#           beginning value 
#       count: int, required
#           ending value
#
# type: "file"
#   generate a sequence of tag values from a file source.
#   The data in the file is sorted, deduplicated and verified is valid UTF-8
#
#       path: string
#           absolute path or relative path to current toml file
tags = [
    # example sequence tag source. The range of values are automatically 
    # prefixed with 0s
    # to ensure correct sort behavior.
    { name = "host", source = { type = "sequence", format = "host-%s", start = 0, count = 5 } },

    # tags can also be sourced from a file. The path is relative to the 
    # schema.toml.
    # Each value must be on a new line. The file is also sorted, deduplicated 
    # and UTF-8 validated.
    { name = "rack", source = { type = "file", path = "files/racks.txt" } },

    # Example string array source, which is also deduplicated and sorted
    { name = "region", source = ["us-west-01","us-west-02","us-east"] },
]

# Keys for defining a field
#
# name: string, required
#   Name of field
#
# count: int, required
#   The maximum number of values to generate. When multiple fields 
#   have the same count and time-spec, they will share timestamps.
#
# A time-spec can be either time-precision or time-interval, which 
# determines how timestamps are generated and may also influence 
# the time range and number of values generated.
#
# time-precision: string [ns, us, ms, s, m, h] (default: ms)
#   Specifies the precision (rounding) for generated timestamps.
#
#   If the precision results in fewer than "count" intervals for the 
#   given time range the number of values will be reduced.
#
#   Example: 
#      count = 1000, start = 0s, end = 100s, time-precison = s
#      100 values will be generated at [0s, 1s, 2s, ..., 99s] 
#
#   If the precision results in greater than "count" intervals for the
#   given time range, the interval will be rounded to the nearest multiple of
#   time-precision.
#
#   Example: 
#      count = 10, start = 0s, end = 100s, time-precison = s
#      100 values will be generated at [0s, 10s, 20s, ..., 90s] 
#
# time-interval: Go duration string (eg 90s, 1h30m)
#   Specifies the delta between generated timestamps. 
#
#   If the delta results in fewer than "count" intervals for the 
#   given time range the number of values will be reduced.
#
#   Example: 
#      count = 100, start = 0s, end = 100s, time-interval = 10s
#      10 values will be generated at [0s, 10s, 20s, ..., 90s] 
#
#   If the delta results in greater than "count" intervals for the
#   given time range, the start-time will be adjusted to ensure "count" values.
#
#   Example: 
#      count = 20, start = 0s, end = 1000s, time-interval = 10s
#      20 values will be generated at [800s, 810s, ..., 900s, ..., 990s] 
#
# source: int, float, boolean, string, array or object
# 
#   A literal int, float, boolean or string will produce 
#   a constant value of the same data type.
#
#   A literal array of homogeneous values will generate a repeating 
#   sequence.
#
#   An object defines more complex generators. The type key determines the
#   type of generator.
#
# source types:
#
# type: "rand<float>" 
#   generate random float values
#       seed: seed to random number generator (default: 0)
#       min:  minimum value (default: 0.0)
#       max:  maximum value (default: 1.0)
#
# type: "zipf<integer>" 
#   generate random integer values using a Zipf distribution
#   The generator generates values k ∈ [0, imax] such that P(k) 
#   is proportional to (v + k) ** (-s). Requirements: s > 1 and v ≥ 1.
#   See https://golang.org/pkg/math/rand/#NewZipf for more information.
#
#       seed: seed to random number generator (default: 0)
#       s:    float > 1 (required)
#       v:    float ≥ 1 (required)
#       imax: integer (required)
#
fields = [
    # Example constant float
    { name = "system", count = 5000, source = 2.5 },
    
    # Example random floats
    { name = "user",   count = 5000, source = { type = "rand<float>", seed = 10, min = 0.0, max = 1.0 } },
]

# Multiple measurements may be defined.
[[measurements]]
name = "mem"
tags = [
    { name = "host",   source = { type = "sequence", format = "host-%s", start = 0, count = 5 } },
    { name = "region", source = ["us-west-01","us-west-02","us-east"] },
]
fields = [
    # An example of a sequence of integer values
    { name = "free",    count = 100, source = [10,15,20,25,30,35,30], time-precision = "ms" },
    { name = "low_mem", count = 100, source = [false,true,true], time-precision = "ms" },
]
`
